ext4: move ext4_ind_* functions from inode.c to indirect.c
Amir Goldstein [Mon, 27 Jun 2011 23:40:50 +0000 (19:40 -0400)]
This patch moves functions from inode.c to indirect.c.
The moved functions are ext4_ind_* functions and their helpers.
Functions called from inode.c are declared extern.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/Makefile
fs/ext4/block_validity.c
fs/ext4/ext4.h
fs/ext4/indirect.c [new file with mode: 0644]
fs/ext4/inode.c

index 0410946..56fd8f8 100644 (file)
@@ -7,7 +7,7 @@ obj-$(CONFIG_EXT4_FS) += ext4.o
 ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o page-io.o \
                ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \
                ext4_jbd2.o migrate.o mballoc.o block_validity.o move_extent.o \
-               mmp.o
+               mmp.o indirect.o
 
 ext4-$(CONFIG_EXT4_FS_XATTR)           += xattr.o xattr_user.o xattr_trusted.o
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)       += acl.o
index af103be..8efb2f0 100644 (file)
@@ -266,3 +266,4 @@ int ext4_check_blockref(const char *function, unsigned int line,
        }
        return 0;
 }
+
index 82ba7eb..ddaf504 100644 (file)
@@ -1834,6 +1834,15 @@ extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
 extern void ext4_da_update_reserve_space(struct inode *inode,
                                        int used, int quota_claim);
+
+/* indirect.c */
+extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
+                               struct ext4_map_blocks *map, int flags);
+extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
+                               const struct iovec *iov, loff_t offset,
+                               unsigned long nr_segs);
+extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
+extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk);
 extern void ext4_ind_truncate(struct inode *inode);
 
 /* ioctl.c */
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
new file mode 100644 (file)
index 0000000..c3e85a8
--- /dev/null
@@ -0,0 +1,1510 @@
+/*
+ *  linux/fs/ext4/indirect.c
+ *
+ *  from
+ *
+ *  linux/fs/ext4/inode.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/inode.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Goal-directed block allocation by Stephen Tweedie
+ *     (sct@redhat.com), 1993, 1998
+ */
+
+#include <linux/module.h>
+#include "ext4_jbd2.h"
+#include "truncate.h"
+
+#include <trace/events/ext4.h>
+
+typedef struct {
+       __le32  *p;
+       __le32  key;
+       struct buffer_head *bh;
+} Indirect;
+
+static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
+{
+       p->key = *(p->p = v);
+       p->bh = bh;
+}
+
+/**
+ *     ext4_block_to_path - parse the block number into array of offsets
+ *     @inode: inode in question (we are only interested in its superblock)
+ *     @i_block: block number to be parsed
+ *     @offsets: array to store the offsets in
+ *     @boundary: set this non-zero if the referred-to block is likely to be
+ *            followed (on disk) by an indirect block.
+ *
+ *     To store the locations of file's data ext4 uses a data structure common
+ *     for UNIX filesystems - tree of pointers anchored in the inode, with
+ *     data blocks at leaves and indirect blocks in intermediate nodes.
+ *     This function translates the block number into path in that tree -
+ *     return value is the path length and @offsets[n] is the offset of
+ *     pointer to (n+1)th node in the nth one. If @block is out of range
+ *     (negative or too large) warning is printed and zero returned.
+ *
+ *     Note: function doesn't find node addresses, so no IO is needed. All
+ *     we need to know is the capacity of indirect blocks (taken from the
+ *     inode->i_sb).
+ */
+
+/*
+ * Portability note: the last comparison (check that we fit into triple
+ * indirect block) is spelled differently, because otherwise on an
+ * architecture with 32-bit longs and 8Kb pages we might get into trouble
+ * if our filesystem had 8Kb blocks. We might use long long, but that would
+ * kill us on x86. Oh, well, at least the sign propagation does not matter -
+ * i_block would have to be negative in the very beginning, so we would not
+ * get there at all.
+ */
+
+static int ext4_block_to_path(struct inode *inode,
+                             ext4_lblk_t i_block,
+                             ext4_lblk_t offsets[4], int *boundary)
+{
+       int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+       int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
+       const long direct_blocks = EXT4_NDIR_BLOCKS,
+               indirect_blocks = ptrs,
+               double_blocks = (1 << (ptrs_bits * 2));
+       int n = 0;
+       int final = 0;
+
+       if (i_block < direct_blocks) {
+               offsets[n++] = i_block;
+               final = direct_blocks;
+       } else if ((i_block -= direct_blocks) < indirect_blocks) {
+               offsets[n++] = EXT4_IND_BLOCK;
+               offsets[n++] = i_block;
+               final = ptrs;
+       } else if ((i_block -= indirect_blocks) < double_blocks) {
+               offsets[n++] = EXT4_DIND_BLOCK;
+               offsets[n++] = i_block >> ptrs_bits;
+               offsets[n++] = i_block & (ptrs - 1);
+               final = ptrs;
+       } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
+               offsets[n++] = EXT4_TIND_BLOCK;
+               offsets[n++] = i_block >> (ptrs_bits * 2);
+               offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
+               offsets[n++] = i_block & (ptrs - 1);
+               final = ptrs;
+       } else {
+               ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
+                            i_block + direct_blocks +
+                            indirect_blocks + double_blocks, inode->i_ino);
+       }
+       if (boundary)
+               *boundary = final - 1 - (i_block & (ptrs - 1));
+       return n;
+}
+
+/**
+ *     ext4_get_branch - read the chain of indirect blocks leading to data
+ *     @inode: inode in question
+ *     @depth: depth of the chain (1 - direct pointer, etc.)
+ *     @offsets: offsets of pointers in inode/indirect blocks
+ *     @chain: place to store the result
+ *     @err: here we store the error value
+ *
+ *     Function fills the array of triples <key, p, bh> and returns %NULL
+ *     if everything went OK or the pointer to the last filled triple
+ *     (incomplete one) otherwise. Upon the return chain[i].key contains
+ *     the number of (i+1)-th block in the chain (as it is stored in memory,
+ *     i.e. little-endian 32-bit), chain[i].p contains the address of that
+ *     number (it points into struct inode for i==0 and into the bh->b_data
+ *     for i>0) and chain[i].bh points to the buffer_head of i-th indirect
+ *     block for i>0 and NULL for i==0. In other words, it holds the block
+ *     numbers of the chain, addresses they were taken from (and where we can
+ *     verify that chain did not change) and buffer_heads hosting these
+ *     numbers.
+ *
+ *     Function stops when it stumbles upon zero pointer (absent block)
+ *             (pointer to last triple returned, *@err == 0)
+ *     or when it gets an IO error reading an indirect block
+ *             (ditto, *@err == -EIO)
+ *     or when it reads all @depth-1 indirect blocks successfully and finds
+ *     the whole chain, all way to the data (returns %NULL, *err == 0).
+ *
+ *      Need to be called with
+ *      down_read(&EXT4_I(inode)->i_data_sem)
+ */
+static Indirect *ext4_get_branch(struct inode *inode, int depth,
+                                ext4_lblk_t  *offsets,
+                                Indirect chain[4], int *err)
+{
+       struct super_block *sb = inode->i_sb;
+       Indirect *p = chain;
+       struct buffer_head *bh;
+
+       *err = 0;
+       /* i_data is not going away, no lock needed */
+       add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
+       if (!p->key)
+               goto no_block;
+       while (--depth) {
+               bh = sb_getblk(sb, le32_to_cpu(p->key));
+               if (unlikely(!bh))
+                       goto failure;
+
+               if (!bh_uptodate_or_lock(bh)) {
+                       if (bh_submit_read(bh) < 0) {
+                               put_bh(bh);
+                               goto failure;
+                       }
+                       /* validate block references */
+                       if (ext4_check_indirect_blockref(inode, bh)) {
+                               put_bh(bh);
+                               goto failure;
+                       }
+               }
+
+               add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
+               /* Reader: end */
+               if (!p->key)
+                       goto no_block;
+       }
+       return NULL;
+
+failure:
+       *err = -EIO;
+no_block:
+       return p;
+}
+
+/**
+ *     ext4_find_near - find a place for allocation with sufficient locality
+ *     @inode: owner
+ *     @ind: descriptor of indirect block.
+ *
+ *     This function returns the preferred place for block allocation.
+ *     It is used when heuristic for sequential allocation fails.
+ *     Rules are:
+ *       + if there is a block to the left of our position - allocate near it.
+ *       + if pointer will live in indirect block - allocate near that block.
+ *       + if pointer will live in inode - allocate in the same
+ *         cylinder group.
+ *
+ * In the latter case we colour the starting block by the callers PID to
+ * prevent it from clashing with concurrent allocations for a different inode
+ * in the same block group.   The PID is used here so that functionally related
+ * files will be close-by on-disk.
+ *
+ *     Caller must make sure that @ind is valid and will stay that way.
+ */
+static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
+{
+       struct ext4_inode_info *ei = EXT4_I(inode);
+       __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
+       __le32 *p;
+       ext4_fsblk_t bg_start;
+       ext4_fsblk_t last_block;
+       ext4_grpblk_t colour;
+       ext4_group_t block_group;
+       int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
+
+       /* Try to find previous block */
+       for (p = ind->p - 1; p >= start; p--) {
+               if (*p)
+                       return le32_to_cpu(*p);
+       }
+
+       /* No such thing, so let's try location of indirect block */
+       if (ind->bh)
+               return ind->bh->b_blocknr;
+
+       /*
+        * It is going to be referred to from the inode itself? OK, just put it
+        * into the same cylinder group then.
+        */
+       block_group = ei->i_block_group;
+       if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
+               block_group &= ~(flex_size-1);
+               if (S_ISREG(inode->i_mode))
+                       block_group++;
+       }
+       bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
+       last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
+
+       /*
+        * If we are doing delayed allocation, we don't need take
+        * colour into account.
+        */
+       if (test_opt(inode->i_sb, DELALLOC))
+               return bg_start;
+
+       if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
+               colour = (current->pid % 16) *
+                       (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+       else
+               colour = (current->pid % 16) * ((last_block - bg_start) / 16);
+       return bg_start + colour;
+}
+
+/**
+ *     ext4_find_goal - find a preferred place for allocation.
+ *     @inode: owner
+ *     @block:  block we want
+ *     @partial: pointer to the last triple within a chain
+ *
+ *     Normally this function find the preferred place for block allocation,
+ *     returns it.
+ *     Because this is only used for non-extent files, we limit the block nr
+ *     to 32 bits.
+ */
+static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
+                                  Indirect *partial)
+{
+       ext4_fsblk_t goal;
+
+       /*
+        * XXX need to get goal block from mballoc's data structures
+        */
+
+       goal = ext4_find_near(inode, partial);
+       goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
+       return goal;
+}
+
+/**
+ *     ext4_blks_to_allocate - Look up the block map and count the number
+ *     of direct blocks need to be allocated for the given branch.
+ *
+ *     @branch: chain of indirect blocks
+ *     @k: number of blocks need for indirect blocks
+ *     @blks: number of data blocks to be mapped.
+ *     @blocks_to_boundary:  the offset in the indirect block
+ *
+ *     return the total number of blocks to be allocate, including the
+ *     direct and indirect blocks.
+ */
+static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
+                                int blocks_to_boundary)
+{
+       unsigned int count = 0;
+
+       /*
+        * Simple case, [t,d]Indirect block(s) has not allocated yet
+        * then it's clear blocks on that path have not allocated
+        */
+       if (k > 0) {
+               /* right now we don't handle cross boundary allocation */
+               if (blks < blocks_to_boundary + 1)
+                       count += blks;
+               else
+                       count += blocks_to_boundary + 1;
+               return count;
+       }
+
+       count++;
+       while (count < blks && count <= blocks_to_boundary &&
+               le32_to_cpu(*(branch[0].p + count)) == 0) {
+               count++;
+       }
+       return count;
+}
+
+/**
+ *     ext4_alloc_blocks: multiple allocate blocks needed for a branch
+ *     @handle: handle for this transaction
+ *     @inode: inode which needs allocated blocks
+ *     @iblock: the logical block to start allocated at
+ *     @goal: preferred physical block of allocation
+ *     @indirect_blks: the number of blocks need to allocate for indirect
+ *                     blocks
+ *     @blks: number of desired blocks
+ *     @new_blocks: on return it will store the new block numbers for
+ *     the indirect blocks(if needed) and the first direct block,
+ *     @err: on return it will store the error code
+ *
+ *     This function will return the number of blocks allocated as
+ *     requested by the passed-in parameters.
+ */
+static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
+                            ext4_lblk_t iblock, ext4_fsblk_t goal,
+                            int indirect_blks, int blks,
+                            ext4_fsblk_t new_blocks[4], int *err)
+{
+       struct ext4_allocation_request ar;
+       int target, i;
+       unsigned long count = 0, blk_allocated = 0;
+       int index = 0;
+       ext4_fsblk_t current_block = 0;
+       int ret = 0;
+
+       /*
+        * Here we try to allocate the requested multiple blocks at once,
+        * on a best-effort basis.
+        * To build a branch, we should allocate blocks for
+        * the indirect blocks(if not allocated yet), and at least
+        * the first direct block of this branch.  That's the
+        * minimum number of blocks need to allocate(required)
+        */
+       /* first we try to allocate the indirect blocks */
+       target = indirect_blks;
+       while (target > 0) {
+               count = target;
+               /* allocating blocks for indirect blocks and direct blocks */
+               current_block = ext4_new_meta_blocks(handle, inode, goal,
+                                                    0, &count, err);
+               if (*err)
+                       goto failed_out;
+
+               if (unlikely(current_block + count > EXT4_MAX_BLOCK_FILE_PHYS)) {
+                       EXT4_ERROR_INODE(inode,
+                                        "current_block %llu + count %lu > %d!",
+                                        current_block, count,
+                                        EXT4_MAX_BLOCK_FILE_PHYS);
+                       *err = -EIO;
+                       goto failed_out;
+               }
+
+               target -= count;
+               /* allocate blocks for indirect blocks */
+               while (index < indirect_blks && count) {
+                       new_blocks[index++] = current_block++;
+                       count--;
+               }
+               if (count > 0) {
+                       /*
+                        * save the new block number
+                        * for the first direct block
+                        */
+                       new_blocks[index] = current_block;
+                       printk(KERN_INFO "%s returned more blocks than "
+                                               "requested\n", __func__);
+                       WARN_ON(1);
+                       break;
+               }
+       }
+
+       target = blks - count ;
+       blk_allocated = count;
+       if (!target)
+               goto allocated;
+       /* Now allocate data blocks */
+       memset(&ar, 0, sizeof(ar));
+       ar.inode = inode;
+       ar.goal = goal;
+       ar.len = target;
+       ar.logical = iblock;
+       if (S_ISREG(inode->i_mode))
+               /* enable in-core preallocation only for regular files */
+               ar.flags = EXT4_MB_HINT_DATA;
+
+       current_block = ext4_mb_new_blocks(handle, &ar, err);
+       if (unlikely(current_block + ar.len > EXT4_MAX_BLOCK_FILE_PHYS)) {
+               EXT4_ERROR_INODE(inode,
+                                "current_block %llu + ar.len %d > %d!",
+                                current_block, ar.len,
+                                EXT4_MAX_BLOCK_FILE_PHYS);
+               *err = -EIO;
+               goto failed_out;
+       }
+
+       if (*err && (target == blks)) {
+               /*
+                * if the allocation failed and we didn't allocate
+                * any blocks before
+                */
+               goto failed_out;
+       }
+       if (!*err) {
+               if (target == blks) {
+                       /*
+                        * save the new block number
+                        * for the first direct block
+                        */
+                       new_blocks[index] = current_block;
+               }
+               blk_allocated += ar.len;
+       }
+allocated:
+       /* total number of blocks allocated for direct blocks */
+       ret = blk_allocated;
+       *err = 0;
+       return ret;
+failed_out:
+       for (i = 0; i < index; i++)
+               ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
+       return ret;
+}
+
+/**
+ *     ext4_alloc_branch - allocate and set up a chain of blocks.
+ *     @handle: handle for this transaction
+ *     @inode: owner
+ *     @indirect_blks: number of allocated indirect blocks
+ *     @blks: number of allocated direct blocks
+ *     @goal: preferred place for allocation
+ *     @offsets: offsets (in the blocks) to store the pointers to next.
+ *     @branch: place to store the chain in.
+ *
+ *     This function allocates blocks, zeroes out all but the last one,
+ *     links them into chain and (if we are synchronous) writes them to disk.
+ *     In other words, it prepares a branch that can be spliced onto the
+ *     inode. It stores the information about that chain in the branch[], in
+ *     the same format as ext4_get_branch() would do. We are calling it after
+ *     we had read the existing part of chain and partial points to the last
+ *     triple of that (one with zero ->key). Upon the exit we have the same
+ *     picture as after the successful ext4_get_block(), except that in one
+ *     place chain is disconnected - *branch->p is still zero (we did not
+ *     set the last link), but branch->key contains the number that should
+ *     be placed into *branch->p to fill that gap.
+ *
+ *     If allocation fails we free all blocks we've allocated (and forget
+ *     their buffer_heads) and return the error value the from failed
+ *     ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
+ *     as described above and return 0.
+ */
+static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
+                            ext4_lblk_t iblock, int indirect_blks,
+                            int *blks, ext4_fsblk_t goal,
+                            ext4_lblk_t *offsets, Indirect *branch)
+{
+       int blocksize = inode->i_sb->s_blocksize;
+       int i, n = 0;
+       int err = 0;
+       struct buffer_head *bh;
+       int num;
+       ext4_fsblk_t new_blocks[4];
+       ext4_fsblk_t current_block;
+
+       num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
+                               *blks, new_blocks, &err);
+       if (err)
+               return err;
+
+       branch[0].key = cpu_to_le32(new_blocks[0]);
+       /*
+        * metadata blocks and data blocks are allocated.
+        */
+       for (n = 1; n <= indirect_blks;  n++) {
+               /*
+                * Get buffer_head for parent block, zero it out
+                * and set the pointer to new one, then send
+                * parent to disk.
+                */
+               bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
+               if (unlikely(!bh)) {
+                       err = -EIO;
+                       goto failed;
+               }
+
+               branch[n].bh = bh;
+               lock_buffer(bh);
+               BUFFER_TRACE(bh, "call get_create_access");
+               err = ext4_journal_get_create_access(handle, bh);
+               if (err) {
+                       /* Don't brelse(bh) here; it's done in
+                        * ext4_journal_forget() below */
+                       unlock_buffer(bh);
+                       goto failed;
+               }
+
+               memset(bh->b_data, 0, blocksize);
+               branch[n].p = (__le32 *) bh->b_data + offsets[n];
+               branch[n].key = cpu_to_le32(new_blocks[n]);
+               *branch[n].p = branch[n].key;
+               if (n == indirect_blks) {
+                       current_block = new_blocks[n];
+                       /*
+                        * End of chain, update the last new metablock of
+                        * the chain to point to the new allocated
+                        * data blocks numbers
+                        */
+                       for (i = 1; i < num; i++)
+                               *(branch[n].p + i) = cpu_to_le32(++current_block);
+               }
+               BUFFER_TRACE(bh, "marking uptodate");
+               set_buffer_uptodate(bh);
+               unlock_buffer(bh);
+
+               BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+               err = ext4_handle_dirty_metadata(handle, inode, bh);
+               if (err)
+                       goto failed;
+       }
+       *blks = num;
+       return err;
+failed:
+       /* Allocation failed, free what we already allocated */
+       ext4_free_blocks(handle, inode, NULL, new_blocks[0], 1, 0);
+       for (i = 1; i <= n ; i++) {
+               /*
+                * branch[i].bh is newly allocated, so there is no
+                * need to revoke the block, which is why we don't
+                * need to set EXT4_FREE_BLOCKS_METADATA.
+                */
+               ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1,
+                                EXT4_FREE_BLOCKS_FORGET);
+       }
+       for (i = n+1; i < indirect_blks; i++)
+               ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
+
+       ext4_free_blocks(handle, inode, NULL, new_blocks[i], num, 0);
+
+       return err;
+}
+
+/**
+ * ext4_splice_branch - splice the allocated branch onto inode.
+ * @handle: handle for this transaction
+ * @inode: owner
+ * @block: (logical) number of block we are adding
+ * @chain: chain of indirect blocks (with a missing link - see
+ *     ext4_alloc_branch)
+ * @where: location of missing link
+ * @num:   number of indirect blocks we are adding
+ * @blks:  number of direct blocks we are adding
+ *
+ * This function fills the missing link and does all housekeeping needed in
+ * inode (->i_blocks, etc.). In case of success we end up with the full
+ * chain to new block and return 0.
+ */
+static int ext4_splice_branch(handle_t *handle, struct inode *inode,
+                             ext4_lblk_t block, Indirect *where, int num,
+                             int blks)
+{
+       int i;
+       int err = 0;
+       ext4_fsblk_t current_block;
+
+       /*
+        * If we're splicing into a [td]indirect block (as opposed to the
+        * inode) then we need to get write access to the [td]indirect block
+        * before the splice.
+        */
+       if (where->bh) {
+               BUFFER_TRACE(where->bh, "get_write_access");
+               err = ext4_journal_get_write_access(handle, where->bh);
+               if (err)
+                       goto err_out;
+       }
+       /* That's it */
+
+       *where->p = where->key;
+
+       /*
+        * Update the host buffer_head or inode to point to more just allocated
+        * direct blocks blocks
+        */
+       if (num == 0 && blks > 1) {
+               current_block = le32_to_cpu(where->key) + 1;
+               for (i = 1; i < blks; i++)
+                       *(where->p + i) = cpu_to_le32(current_block++);
+       }
+
+       /* We are done with atomic stuff, now do the rest of housekeeping */
+       /* had we spliced it onto indirect block? */
+       if (where->bh) {
+               /*
+                * If we spliced it onto an indirect block, we haven't
+                * altered the inode.  Note however that if it is being spliced
+                * onto an indirect block at the very end of the file (the
+                * file is growing) then we *will* alter the inode to reflect
+                * the new i_size.  But that is not done here - it is done in
+                * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
+                */
+               jbd_debug(5, "splicing indirect only\n");
+               BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
+               err = ext4_handle_dirty_metadata(handle, inode, where->bh);
+               if (err)
+                       goto err_out;
+       } else {
+               /*
+                * OK, we spliced it into the inode itself on a direct block.
+                */
+               ext4_mark_inode_dirty(handle, inode);
+               jbd_debug(5, "splicing direct\n");
+       }
+       return err;
+
+err_out:
+       for (i = 1; i <= num; i++) {
+               /*
+                * branch[i].bh is newly allocated, so there is no
+                * need to revoke the block, which is why we don't
+                * need to set EXT4_FREE_BLOCKS_METADATA.
+                */
+               ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
+                                EXT4_FREE_BLOCKS_FORGET);
+       }
+       ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key),
+                        blks, 0);
+
+       return err;
+}
+
+/*
+ * The ext4_ind_map_blocks() function handles non-extents inodes
+ * (i.e., using the traditional indirect/double-indirect i_blocks
+ * scheme) for ext4_map_blocks().
+ *
+ * Allocation strategy is simple: if we have to allocate something, we will
+ * have to go the whole way to leaf. So let's do it before attaching anything
+ * to tree, set linkage between the newborn blocks, write them if sync is
+ * required, recheck the path, free and repeat if check fails, otherwise
+ * set the last missing link (that will protect us from any truncate-generated
+ * removals - all blocks on the path are immune now) and possibly force the
+ * write on the parent block.
+ * That has a nice additional property: no special recovery from the failed
+ * allocations is needed - we simply release blocks and do not touch anything
+ * reachable from inode.
+ *
+ * `handle' can be NULL if create == 0.
+ *
+ * return > 0, # of blocks mapped or allocated.
+ * return = 0, if plain lookup failed.
+ * return < 0, error case.
+ *
+ * The ext4_ind_get_blocks() function should be called with
+ * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
+ * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
+ * blocks.
+ */
+int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
+                       struct ext4_map_blocks *map,
+                       int flags)
+{
+       int err = -EIO;
+       ext4_lblk_t offsets[4];
+       Indirect chain[4];
+       Indirect *partial;
+       ext4_fsblk_t goal;
+       int indirect_blks;
+       int blocks_to_boundary = 0;
+       int depth;
+       int count = 0;
+       ext4_fsblk_t first_block = 0;
+
+       trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
+       J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
+       J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
+       depth = ext4_block_to_path(inode, map->m_lblk, offsets,
+                                  &blocks_to_boundary);
+
+       if (depth == 0)
+               goto out;
+
+       partial = ext4_get_branch(inode, depth, offsets, chain, &err);
+
+       /* Simplest case - block found, no allocation needed */
+       if (!partial) {
+               first_block = le32_to_cpu(chain[depth - 1].key);
+               count++;
+               /*map more blocks*/
+               while (count < map->m_len && count <= blocks_to_boundary) {
+                       ext4_fsblk_t blk;
+
+                       blk = le32_to_cpu(*(chain[depth-1].p + count));
+
+                       if (blk == first_block + count)
+                               count++;
+                       else
+                               break;
+               }
+               goto got_it;
+       }
+
+       /* Next simple case - plain lookup or failed read of indirect block */
+       if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
+               goto cleanup;
+
+       /*
+        * Okay, we need to do block allocation.
+       */
+       goal = ext4_find_goal(inode, map->m_lblk, partial);
+
+       /* the number of blocks need to allocate for [d,t]indirect blocks */
+       indirect_blks = (chain + depth) - partial - 1;
+
+       /*
+        * Next look up the indirect map to count the totoal number of
+        * direct blocks to allocate for this branch.
+        */
+       count = ext4_blks_to_allocate(partial, indirect_blks,
+                                     map->m_len, blocks_to_boundary);
+       /*
+        * Block out ext4_truncate while we alter the tree
+        */
+       err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
+                               &count, goal,
+                               offsets + (partial - chain), partial);
+
+       /*
+        * The ext4_splice_branch call will free and forget any buffers
+        * on the new chain if there is a failure, but that risks using
+        * up transaction credits, especially for bitmaps where the
+        * credits cannot be returned.  Can we handle this somehow?  We
+        * may need to return -EAGAIN upwards in the worst case.  --sct
+        */
+       if (!err)
+               err = ext4_splice_branch(handle, inode, map->m_lblk,
+                                        partial, indirect_blks, count);
+       if (err)
+               goto cleanup;
+
+       map->m_flags |= EXT4_MAP_NEW;
+
+       ext4_update_inode_fsync_trans(handle, inode, 1);
+got_it:
+       map->m_flags |= EXT4_MAP_MAPPED;
+       map->m_pblk = le32_to_cpu(chain[depth-1].key);
+       map->m_len = count;
+       if (count > blocks_to_boundary)
+               map->m_flags |= EXT4_MAP_BOUNDARY;
+       err = count;
+       /* Clean up and exit */
+       partial = chain + depth - 1;    /* the whole chain */
+cleanup:
+       while (partial > chain) {
+               BUFFER_TRACE(partial->bh, "call brelse");
+               brelse(partial->bh);
+               partial--;
+       }
+out:
+       trace_ext4_ind_map_blocks_exit(inode, map->m_lblk,
+                               map->m_pblk, map->m_len, err);
+       return err;
+}
+
+/*
+ * O_DIRECT for ext3 (or indirect map) based files
+ *
+ * If the O_DIRECT write will extend the file then add this inode to the
+ * orphan list.  So recovery will truncate it back to the original size
+ * if the machine crashes during the write.
+ *
+ * If the O_DIRECT write is intantiating holes inside i_size and the machine
+ * crashes then stale disk data _may_ be exposed inside the file. But current
+ * VFS code falls back into buffered path in that case so we are safe.
+ */
+ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
+                          const struct iovec *iov, loff_t offset,
+                          unsigned long nr_segs)
+{
+       struct file *file = iocb->ki_filp;
+       struct inode *inode = file->f_mapping->host;
+       struct ext4_inode_info *ei = EXT4_I(inode);
+       handle_t *handle;
+       ssize_t ret;
+       int orphan = 0;
+       size_t count = iov_length(iov, nr_segs);
+       int retries = 0;
+
+       if (rw == WRITE) {
+               loff_t final_size = offset + count;
+
+               if (final_size > inode->i_size) {
+                       /* Credits for sb + inode write */
+                       handle = ext4_journal_start(inode, 2);
+                       if (IS_ERR(handle)) {
+                               ret = PTR_ERR(handle);
+                               goto out;
+                       }
+                       ret = ext4_orphan_add(handle, inode);
+                       if (ret) {
+                               ext4_journal_stop(handle);
+                               goto out;
+                       }
+                       orphan = 1;
+                       ei->i_disksize = inode->i_size;
+                       ext4_journal_stop(handle);
+               }
+       }
+
+retry:
+       if (rw == READ && ext4_should_dioread_nolock(inode))
+               ret = __blockdev_direct_IO(rw, iocb, inode,
+                                inode->i_sb->s_bdev, iov,
+                                offset, nr_segs,
+                                ext4_get_block, NULL, NULL, 0);
+       else {
+               ret = blockdev_direct_IO(rw, iocb, inode,
+                                inode->i_sb->s_bdev, iov,
+                                offset, nr_segs,
+                                ext4_get_block, NULL);
+
+               if (unlikely((rw & WRITE) && ret < 0)) {
+                       loff_t isize = i_size_read(inode);
+                       loff_t end = offset + iov_length(iov, nr_segs);
+
+                       if (end > isize)
+                               ext4_truncate_failed_write(inode);
+               }
+       }
+       if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+               goto retry;
+
+       if (orphan) {
+               int err;
+
+               /* Credits for sb + inode write */
+               handle = ext4_journal_start(inode, 2);
+               if (IS_ERR(handle)) {
+                       /* This is really bad luck. We've written the data
+                        * but cannot extend i_size. Bail out and pretend
+                        * the write failed... */
+                       ret = PTR_ERR(handle);
+                       if (inode->i_nlink)
+                               ext4_orphan_del(NULL, inode);
+
+                       goto out;
+               }
+               if (inode->i_nlink)
+                       ext4_orphan_del(handle, inode);
+               if (ret > 0) {
+                       loff_t end = offset + ret;
+                       if (end > inode->i_size) {
+                               ei->i_disksize = end;
+                               i_size_write(inode, end);
+                               /*
+                                * We're going to return a positive `ret'
+                                * here due to non-zero-length I/O, so there's
+                                * no way of reporting error returns from
+                                * ext4_mark_inode_dirty() to userspace.  So
+                                * ignore it.
+                                */
+                               ext4_mark_inode_dirty(handle, inode);
+                       }
+               }
+               err = ext4_journal_stop(handle);
+               if (ret == 0)
+                       ret = err;
+       }
+out:
+       return ret;
+}
+
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate a new block at @lblocks for non extent file based file
+ */
+int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock)
+{
+       struct ext4_inode_info *ei = EXT4_I(inode);
+       sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
+       int blk_bits;
+
+       if (lblock < EXT4_NDIR_BLOCKS)
+               return 0;
+
+       lblock -= EXT4_NDIR_BLOCKS;
+
+       if (ei->i_da_metadata_calc_len &&
+           (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
+               ei->i_da_metadata_calc_len++;
+               return 0;
+       }
+       ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
+       ei->i_da_metadata_calc_len = 1;
+       blk_bits = order_base_2(lblock);
+       return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
+}
+
+int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+       int indirects;
+
+       /* if nrblocks are contiguous */
+       if (chunk) {
+               /*
+                * With N contiguous data blocks, we need at most
+                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+                * 2 dindirect blocks, and 1 tindirect block
+                */
+               return DIV_ROUND_UP(nrblocks,
+                                   EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
+       }
+       /*
+        * if nrblocks are not contiguous, worse case, each block touch
+        * a indirect block, and each indirect block touch a double indirect
+        * block, plus a triple indirect block
+        */
+       indirects = nrblocks * 2 + 1;
+       return indirects;
+}
+
+/*
+ * Truncate transactions can be complex and absolutely huge.  So we need to
+ * be able to restart the transaction at a conventient checkpoint to make
+ * sure we don't overflow the journal.
+ *
+ * start_transaction gets us a new handle for a truncate transaction,
+ * and extend_transaction tries to extend the existing one a bit.  If
+ * extend fails, we need to propagate the failure up and restart the
+ * transaction in the top-level truncate loop. --sct
+ */
+static handle_t *start_transaction(struct inode *inode)
+{
+       handle_t *result;
+
+       result = ext4_journal_start(inode, ext4_blocks_for_truncate(inode));
+       if (!IS_ERR(result))
+               return result;
+
+       ext4_std_error(inode->i_sb, PTR_ERR(result));
+       return result;
+}
+
+/*
+ * Try to extend this transaction for the purposes of truncation.
+ *
+ * Returns 0 if we managed to create more room.  If we can't create more
+ * room, and the transaction must be restarted we return 1.
+ */
+static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
+{
+       if (!ext4_handle_valid(handle))
+               return 0;
+       if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
+               return 0;
+       if (!ext4_journal_extend(handle, ext4_blocks_for_truncate(inode)))
+               return 0;
+       return 1;
+}
+
+/*
+ * Probably it should be a library function... search for first non-zero word
+ * or memcmp with zero_page, whatever is better for particular architecture.
+ * Linus?
+ */
+static inline int all_zeroes(__le32 *p, __le32 *q)
+{
+       while (p < q)
+               if (*p++)
+                       return 0;
+       return 1;
+}
+
+/**
+ *     ext4_find_shared - find the indirect blocks for partial truncation.
+ *     @inode:   inode in question
+ *     @depth:   depth of the affected branch
+ *     @offsets: offsets of pointers in that branch (see ext4_block_to_path)
+ *     @chain:   place to store the pointers to partial indirect blocks
+ *     @top:     place to the (detached) top of branch
+ *
+ *     This is a helper function used by ext4_truncate().
+ *
+ *     When we do truncate() we may have to clean the ends of several
+ *     indirect blocks but leave the blocks themselves alive. Block is
+ *     partially truncated if some data below the new i_size is referred
+ *     from it (and it is on the path to the first completely truncated
+ *     data block, indeed).  We have to free the top of that path along
+ *     with everything to the right of the path. Since no allocation
+ *     past the truncation point is possible until ext4_truncate()
+ *     finishes, we may safely do the latter, but top of branch may
+ *     require special attention - pageout below the truncation point
+ *     might try to populate it.
+ *
+ *     We atomically detach the top of branch from the tree, store the
+ *     block number of its root in *@top, pointers to buffer_heads of
+ *     partially truncated blocks - in @chain[].bh and pointers to
+ *     their last elements that should not be removed - in
+ *     @chain[].p. Return value is the pointer to last filled element
+ *     of @chain.
+ *
+ *     The work left to caller to do the actual freeing of subtrees:
+ *             a) free the subtree starting from *@top
+ *             b) free the subtrees whose roots are stored in
+ *                     (@chain[i].p+1 .. end of @chain[i].bh->b_data)
+ *             c) free the subtrees growing from the inode past the @chain[0].
+ *                     (no partially truncated stuff there).  */
+
+static Indirect *ext4_find_shared(struct inode *inode, int depth,
+                                 ext4_lblk_t offsets[4], Indirect chain[4],
+                                 __le32 *top)
+{
+       Indirect *partial, *p;
+       int k, err;
+
+       *top = 0;
+       /* Make k index the deepest non-null offset + 1 */
+       for (k = depth; k > 1 && !offsets[k-1]; k--)
+               ;
+       partial = ext4_get_branch(inode, k, offsets, chain, &err);
+       /* Writer: pointers */
+       if (!partial)
+               partial = chain + k-1;
+       /*
+        * If the branch acquired continuation since we've looked at it -
+        * fine, it should all survive and (new) top doesn't belong to us.
+        */
+       if (!partial->key && *partial->p)
+               /* Writer: end */
+               goto no_top;
+       for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
+               ;
+       /*
+        * OK, we've found the last block that must survive. The rest of our
+        * branch should be detached before unlocking. However, if that rest
+        * of branch is all ours and does not grow immediately from the inode
+        * it's easier to cheat and just decrement partial->p.
+        */
+       if (p == chain + k - 1 && p > chain) {
+               p->p--;
+       } else {
+               *top = *p->p;
+               /* Nope, don't do this in ext4.  Must leave the tree intact */
+#if 0
+               *p->p = 0;
+#endif
+       }
+       /* Writer: end */
+
+       while (partial > p) {
+               brelse(partial->bh);
+               partial--;
+       }
+no_top:
+       return partial;
+}
+
+/*
+ * Zero a number of block pointers in either an inode or an indirect block.
+ * If we restart the transaction we must again get write access to the
+ * indirect block for further modification.
+ *
+ * We release `count' blocks on disk, but (last - first) may be greater
+ * than `count' because there can be holes in there.
+ *
+ * Return 0 on success, 1 on invalid block range
+ * and < 0 on fatal error.
+ */
+static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
+                            struct buffer_head *bh,
+                            ext4_fsblk_t block_to_free,
+                            unsigned long count, __le32 *first,
+                            __le32 *last)
+{
+       __le32 *p;
+       int     flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
+       int     err;
+
+       if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+               flags |= EXT4_FREE_BLOCKS_METADATA;
+
+       if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
+                                  count)) {
+               EXT4_ERROR_INODE(inode, "attempt to clear invalid "
+                                "blocks %llu len %lu",
+                                (unsigned long long) block_to_free, count);
+               return 1;
+       }
+
+       if (try_to_extend_transaction(handle, inode)) {
+               if (bh) {
+                       BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+                       err = ext4_handle_dirty_metadata(handle, inode, bh);
+                       if (unlikely(err))
+                               goto out_err;
+               }
+               err = ext4_mark_inode_dirty(handle, inode);
+               if (unlikely(err))
+                       goto out_err;
+               err = ext4_truncate_restart_trans(handle, inode,
+                                       ext4_blocks_for_truncate(inode));
+               if (unlikely(err))
+                       goto out_err;
+               if (bh) {
+                       BUFFER_TRACE(bh, "retaking write access");
+                       err = ext4_journal_get_write_access(handle, bh);
+                       if (unlikely(err))
+                               goto out_err;
+               }
+       }
+
+       for (p = first; p < last; p++)
+               *p = 0;
+
+       ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
+       return 0;
+out_err:
+       ext4_std_error(inode->i_sb, err);
+       return err;
+}
+
+/**
+ * ext4_free_data - free a list of data blocks
+ * @handle:    handle for this transaction
+ * @inode:     inode we are dealing with
+ * @this_bh:   indirect buffer_head which contains *@first and *@last
+ * @first:     array of block numbers
+ * @last:      points immediately past the end of array
+ *
+ * We are freeing all blocks referred from that array (numbers are stored as
+ * little-endian 32-bit) and updating @inode->i_blocks appropriately.
+ *
+ * We accumulate contiguous runs of blocks to free.  Conveniently, if these
+ * blocks are contiguous then releasing them at one time will only affect one
+ * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
+ * actually use a lot of journal space.
+ *
+ * @this_bh will be %NULL if @first and @last point into the inode's direct
+ * block pointers.
+ */
+static void ext4_free_data(handle_t *handle, struct inode *inode,
+                          struct buffer_head *this_bh,
+                          __le32 *first, __le32 *last)
+{
+       ext4_fsblk_t block_to_free = 0;    /* Starting block # of a run */
+       unsigned long count = 0;            /* Number of blocks in the run */
+       __le32 *block_to_free_p = NULL;     /* Pointer into inode/ind
+                                              corresponding to
+                                              block_to_free */
+       ext4_fsblk_t nr;                    /* Current block # */
+       __le32 *p;                          /* Pointer into inode/ind
+                                              for current block */
+       int err = 0;
+
+       if (this_bh) {                          /* For indirect block */
+               BUFFER_TRACE(this_bh, "get_write_access");
+               err = ext4_journal_get_write_access(handle, this_bh);
+               /* Important: if we can't update the indirect pointers
+                * to the blocks, we can't free them. */
+               if (err)
+                       return;
+       }
+
+       for (p = first; p < last; p++) {
+               nr = le32_to_cpu(*p);
+               if (nr) {
+                       /* accumulate blocks to free if they're contiguous */
+                       if (count == 0) {
+                               block_to_free = nr;
+                               block_to_free_p = p;
+                               count = 1;
+                       } else if (nr == block_to_free + count) {
+                               count++;
+                       } else {
+                               err = ext4_clear_blocks(handle, inode, this_bh,
+                                                       block_to_free, count,
+                                                       block_to_free_p, p);
+                               if (err)
+                                       break;
+                               block_to_free = nr;
+                               block_to_free_p = p;
+                               count = 1;
+                       }
+               }
+       }
+
+       if (!err && count > 0)
+               err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,
+                                       count, block_to_free_p, p);
+       if (err < 0)
+               /* fatal error */
+               return;
+
+       if (this_bh) {
+               BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
+
+               /*
+                * The buffer head should have an attached journal head at this
+                * point. However, if the data is corrupted and an indirect
+                * block pointed to itself, it would have been detached when
+                * the block was cleared. Check for this instead of OOPSing.
+                */
+               if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
+                       ext4_handle_dirty_metadata(handle, inode, this_bh);
+               else
+                       EXT4_ERROR_INODE(inode,
+                                        "circular indirect block detected at "
+                                        "block %llu",
+                               (unsigned long long) this_bh->b_blocknr);
+       }
+}
+
+/**
+ *     ext4_free_branches - free an array of branches
+ *     @handle: JBD handle for this transaction
+ *     @inode: inode we are dealing with
+ *     @parent_bh: the buffer_head which contains *@first and *@last
+ *     @first: array of block numbers
+ *     @last:  pointer immediately past the end of array
+ *     @depth: depth of the branches to free
+ *
+ *     We are freeing all blocks referred from these branches (numbers are
+ *     stored as little-endian 32-bit) and updating @inode->i_blocks
+ *     appropriately.
+ */
+static void ext4_free_branches(handle_t *handle, struct inode *inode,
+                              struct buffer_head *parent_bh,
+                              __le32 *first, __le32 *last, int depth)
+{
+       ext4_fsblk_t nr;
+       __le32 *p;
+
+       if (ext4_handle_is_aborted(handle))
+               return;
+
+       if (depth--) {
+               struct buffer_head *bh;
+               int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+               p = last;
+               while (--p >= first) {
+                       nr = le32_to_cpu(*p);
+                       if (!nr)
+                               continue;               /* A hole */
+
+                       if (!ext4_data_block_valid(EXT4_SB(inode->i_sb),
+                                                  nr, 1)) {
+                               EXT4_ERROR_INODE(inode,
+                                                "invalid indirect mapped "
+                                                "block %lu (level %d)",
+                                                (unsigned long) nr, depth);
+                               break;
+                       }
+
+                       /* Go read the buffer for the next level down */
+                       bh = sb_bread(inode->i_sb, nr);
+
+                       /*
+                        * A read failure? Report error and clear slot
+                        * (should be rare).
+                        */
+                       if (!bh) {
+                               EXT4_ERROR_INODE_BLOCK(inode, nr,
+                                                      "Read failure");
+                               continue;
+                       }
+
+                       /* This zaps the entire block.  Bottom up. */
+                       BUFFER_TRACE(bh, "free child branches");
+                       ext4_free_branches(handle, inode, bh,
+                                       (__le32 *) bh->b_data,
+                                       (__le32 *) bh->b_data + addr_per_block,
+                                       depth);
+                       brelse(bh);
+
+                       /*
+                        * Everything below this this pointer has been
+                        * released.  Now let this top-of-subtree go.
+                        *
+                        * We want the freeing of this indirect block to be
+                        * atomic in the journal with the updating of the
+                        * bitmap block which owns it.  So make some room in
+                        * the journal.
+                        *
+                        * We zero the parent pointer *after* freeing its
+                        * pointee in the bitmaps, so if extend_transaction()
+                        * for some reason fails to put the bitmap changes and
+                        * the release into the same transaction, recovery
+                        * will merely complain about releasing a free block,
+                        * rather than leaking blocks.
+                        */
+                       if (ext4_handle_is_aborted(handle))
+                               return;
+                       if (try_to_extend_transaction(handle, inode)) {
+                               ext4_mark_inode_dirty(handle, inode);
+                               ext4_truncate_restart_trans(handle, inode,
+                                           ext4_blocks_for_truncate(inode));
+                       }
+
+                       /*
+                        * The forget flag here is critical because if
+                        * we are journaling (and not doing data
+                        * journaling), we have to make sure a revoke
+                        * record is written to prevent the journal
+                        * replay from overwriting the (former)
+                        * indirect block if it gets reallocated as a
+                        * data block.  This must happen in the same
+                        * transaction where the data blocks are
+                        * actually freed.
+                        */
+                       ext4_free_blocks(handle, inode, NULL, nr, 1,
+                                        EXT4_FREE_BLOCKS_METADATA|
+                                        EXT4_FREE_BLOCKS_FORGET);
+
+                       if (parent_bh) {
+                               /*
+                                * The block which we have just freed is
+                                * pointed to by an indirect block: journal it
+                                */
+                               BUFFER_TRACE(parent_bh, "get_write_access");
+                               if (!ext4_journal_get_write_access(handle,
+                                                                  parent_bh)){
+                                       *p = 0;
+                                       BUFFER_TRACE(parent_bh,
+                                       "call ext4_handle_dirty_metadata");
+                                       ext4_handle_dirty_metadata(handle,
+                                                                  inode,
+                                                                  parent_bh);
+                               }
+                       }
+               }
+       } else {
+               /* We have reached the bottom of the tree. */
+               BUFFER_TRACE(parent_bh, "free data blocks");
+               ext4_free_data(handle, inode, parent_bh, first, last);
+       }
+}
+
+void ext4_ind_truncate(struct inode *inode)
+{
+       handle_t *handle;
+       struct ext4_inode_info *ei = EXT4_I(inode);
+       __le32 *i_data = ei->i_data;
+       int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+       struct address_space *mapping = inode->i_mapping;
+       ext4_lblk_t offsets[4];
+       Indirect chain[4];
+       Indirect *partial;
+       __le32 nr = 0;
+       int n = 0;
+       ext4_lblk_t last_block, max_block;
+       unsigned blocksize = inode->i_sb->s_blocksize;
+
+       handle = start_transaction(inode);
+       if (IS_ERR(handle))
+               return;         /* AKPM: return what? */
+
+       last_block = (inode->i_size + blocksize-1)
+                                       >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+       max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
+                                       >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+
+       if (inode->i_size & (blocksize - 1))
+               if (ext4_block_truncate_page(handle, mapping, inode->i_size))
+                       goto out_stop;
+
+       if (last_block != max_block) {
+               n = ext4_block_to_path(inode, last_block, offsets, NULL);
+               if (n == 0)
+                       goto out_stop;  /* error */
+       }
+
+       /*
+        * OK.  This truncate is going to happen.  We add the inode to the
+        * orphan list, so that if this truncate spans multiple transactions,
+        * and we crash, we will resume the truncate when the filesystem
+        * recovers.  It also marks the inode dirty, to catch the new size.
+        *
+        * Implication: the file must always be in a sane, consistent
+        * truncatable state while each transaction commits.
+        */
+       if (ext4_orphan_add(handle, inode))
+               goto out_stop;
+
+       /*
+        * From here we block out all ext4_get_block() callers who want to
+        * modify the block allocation tree.
+        */
+       down_write(&ei->i_data_sem);
+
+       ext4_discard_preallocations(inode);
+
+       /*
+        * The orphan list entry will now protect us from any crash which
+        * occurs before the truncate completes, so it is now safe to propagate
+        * the new, shorter inode size (held for now in i_size) into the
+        * on-disk inode. We do this via i_disksize, which is the value which
+        * ext4 *really* writes onto the disk inode.
+        */
+       ei->i_disksize = inode->i_size;
+
+       if (last_block == max_block) {
+               /*
+                * It is unnecessary to free any data blocks if last_block is
+                * equal to the indirect block limit.
+                */
+               goto out_unlock;
+       } else if (n == 1) {            /* direct blocks */
+               ext4_free_data(handle, inode, NULL, i_data+offsets[0],
+                              i_data + EXT4_NDIR_BLOCKS);
+               goto do_indirects;
+       }
+
+       partial = ext4_find_shared(inode, n, offsets, chain, &nr);
+       /* Kill the top of shared branch (not detached) */
+       if (nr) {
+               if (partial == chain) {
+                       /* Shared branch grows from the inode */
+                       ext4_free_branches(handle, inode, NULL,
+                                          &nr, &nr+1, (chain+n-1) - partial);
+                       *partial->p = 0;
+                       /*
+                        * We mark the inode dirty prior to restart,
+                        * and prior to stop.  No need for it here.
+                        */
+               } else {
+                       /* Shared branch grows from an indirect block */
+                       BUFFER_TRACE(partial->bh, "get_write_access");
+                       ext4_free_branches(handle, inode, partial->bh,
+                                       partial->p,
+                                       partial->p+1, (chain+n-1) - partial);
+               }
+       }
+       /* Clear the ends of indirect blocks on the shared branch */
+       while (partial > chain) {
+               ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
+                                  (__le32*)partial->bh->b_data+addr_per_block,
+                                  (chain+n-1) - partial);
+               BUFFER_TRACE(partial->bh, "call brelse");
+               brelse(partial->bh);
+               partial--;
+       }
+do_indirects:
+       /* Kill the remaining (whole) subtrees */
+       switch (offsets[0]) {
+       default:
+               nr = i_data[EXT4_IND_BLOCK];
+               if (nr) {
+                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
+                       i_data[EXT4_IND_BLOCK] = 0;
+               }
+       case EXT4_IND_BLOCK:
+               nr = i_data[EXT4_DIND_BLOCK];
+               if (nr) {
+                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
+                       i_data[EXT4_DIND_BLOCK] = 0;
+               }
+       case EXT4_DIND_BLOCK:
+               nr = i_data[EXT4_TIND_BLOCK];
+               if (nr) {
+                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
+                       i_data[EXT4_TIND_BLOCK] = 0;
+               }
+       case EXT4_TIND_BLOCK:
+               ;
+       }
+
+out_unlock:
+       up_write(&ei->i_data_sem);
+       inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+       ext4_mark_inode_dirty(handle, inode);
+
+       /*
+        * In a multi-transaction truncate, we only make the final transaction
+        * synchronous
+        */
+       if (IS_SYNC(inode))
+               ext4_handle_sync(handle);
+out_stop:
+       /*
+        * If this was a simple ftruncate(), and the file will remain alive
+        * then we need to clear up the orphan record which we created above.
+        * However, if this was a real unlink then we were called by
+        * ext4_delete_inode(), and we allow that function to clean up the
+        * orphan info for us.
+        */
+       if (inode->i_nlink)
+               ext4_orphan_del(handle, inode);
+
+       ext4_journal_stop(handle);
+       trace_ext4_truncate_exit(inode);
+}
+
index 9b82ac7..de50b16 100644 (file)
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
- *  Goal-directed block allocation by Stephen Tweedie
- *     (sct@redhat.com), 1993, 1998
- *  Big-endian to little-endian byte-swapping/bitmaps by
- *        David S. Miller (davem@caip.rutgers.edu), 1995
  *  64-bit file support on 64-bit platforms by Jakub Jelinek
  *     (jj@sunsite.ms.mff.cuni.cz)
  *
@@ -90,45 +86,6 @@ static int ext4_inode_is_fast_symlink(struct inode *inode)
 }
 
 /*
- * Truncate transactions can be complex and absolutely huge.  So we need to
- * be able to restart the transaction at a conventient checkpoint to make
- * sure we don't overflow the journal.
- *
- * start_transaction gets us a new handle for a truncate transaction,
- * and extend_transaction tries to extend the existing one a bit.  If
- * extend fails, we need to propagate the failure up and restart the
- * transaction in the top-level truncate loop. --sct
- */
-static handle_t *start_transaction(struct inode *inode)
-{
-       handle_t *result;
-
-       result = ext4_journal_start(inode, ext4_blocks_for_truncate(inode));
-       if (!IS_ERR(result))
-               return result;
-
-       ext4_std_error(inode->i_sb, PTR_ERR(result));
-       return result;
-}
-
-/*
- * Try to extend this transaction for the purposes of truncation.
- *
- * Returns 0 if we managed to create more room.  If we can't create more
- * room, and the transaction must be restarted we return 1.
- */
-static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
-{
-       if (!ext4_handle_valid(handle))
-               return 0;
-       if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
-               return 0;
-       if (!ext4_journal_extend(handle, ext4_blocks_for_truncate(inode)))
-               return 0;
-       return 1;
-}
-
-/*
  * Restart the transaction associated with *handle.  This does a commit,
  * so before we call here everything must be consistently dirtied against
  * this transaction.
@@ -251,760 +208,6 @@ no_delete:
        ext4_clear_inode(inode);        /* We must guarantee clearing of inode... */
 }
 
-typedef struct {
-       __le32  *p;
-       __le32  key;
-       struct buffer_head *bh;
-} Indirect;
-
-static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
-{
-       p->key = *(p->p = v);
-       p->bh = bh;
-}
-
-/**
- *     ext4_block_to_path - parse the block number into array of offsets
- *     @inode: inode in question (we are only interested in its superblock)
- *     @i_block: block number to be parsed
- *     @offsets: array to store the offsets in
- *     @boundary: set this non-zero if the referred-to block is likely to be
- *            followed (on disk) by an indirect block.
- *
- *     To store the locations of file's data ext4 uses a data structure common
- *     for UNIX filesystems - tree of pointers anchored in the inode, with
- *     data blocks at leaves and indirect blocks in intermediate nodes.
- *     This function translates the block number into path in that tree -
- *     return value is the path length and @offsets[n] is the offset of
- *     pointer to (n+1)th node in the nth one. If @block is out of range
- *     (negative or too large) warning is printed and zero returned.
- *
- *     Note: function doesn't find node addresses, so no IO is needed. All
- *     we need to know is the capacity of indirect blocks (taken from the
- *     inode->i_sb).
- */
-
-/*
- * Portability note: the last comparison (check that we fit into triple
- * indirect block) is spelled differently, because otherwise on an
- * architecture with 32-bit longs and 8Kb pages we might get into trouble
- * if our filesystem had 8Kb blocks. We might use long long, but that would
- * kill us on x86. Oh, well, at least the sign propagation does not matter -
- * i_block would have to be negative in the very beginning, so we would not
- * get there at all.
- */
-
-static int ext4_block_to_path(struct inode *inode,
-                             ext4_lblk_t i_block,
-                             ext4_lblk_t offsets[4], int *boundary)
-{
-       int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
-       int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
-       const long direct_blocks = EXT4_NDIR_BLOCKS,
-               indirect_blocks = ptrs,
-               double_blocks = (1 << (ptrs_bits * 2));
-       int n = 0;
-       int final = 0;
-
-       if (i_block < direct_blocks) {
-               offsets[n++] = i_block;
-               final = direct_blocks;
-       } else if ((i_block -= direct_blocks) < indirect_blocks) {
-               offsets[n++] = EXT4_IND_BLOCK;
-               offsets[n++] = i_block;
-               final = ptrs;
-       } else if ((i_block -= indirect_blocks) < double_blocks) {
-               offsets[n++] = EXT4_DIND_BLOCK;
-               offsets[n++] = i_block >> ptrs_bits;
-               offsets[n++] = i_block & (ptrs - 1);
-               final = ptrs;
-       } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
-               offsets[n++] = EXT4_TIND_BLOCK;
-               offsets[n++] = i_block >> (ptrs_bits * 2);
-               offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
-               offsets[n++] = i_block & (ptrs - 1);
-               final = ptrs;
-       } else {
-               ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
-                            i_block + direct_blocks +
-                            indirect_blocks + double_blocks, inode->i_ino);
-       }
-       if (boundary)
-               *boundary = final - 1 - (i_block & (ptrs - 1));
-       return n;
-}
-
-/**
- *     ext4_get_branch - read the chain of indirect blocks leading to data
- *     @inode: inode in question
- *     @depth: depth of the chain (1 - direct pointer, etc.)
- *     @offsets: offsets of pointers in inode/indirect blocks
- *     @chain: place to store the result
- *     @err: here we store the error value
- *
- *     Function fills the array of triples <key, p, bh> and returns %NULL
- *     if everything went OK or the pointer to the last filled triple
- *     (incomplete one) otherwise. Upon the return chain[i].key contains
- *     the number of (i+1)-th block in the chain (as it is stored in memory,
- *     i.e. little-endian 32-bit), chain[i].p contains the address of that
- *     number (it points into struct inode for i==0 and into the bh->b_data
- *     for i>0) and chain[i].bh points to the buffer_head of i-th indirect
- *     block for i>0 and NULL for i==0. In other words, it holds the block
- *     numbers of the chain, addresses they were taken from (and where we can
- *     verify that chain did not change) and buffer_heads hosting these
- *     numbers.
- *
- *     Function stops when it stumbles upon zero pointer (absent block)
- *             (pointer to last triple returned, *@err == 0)
- *     or when it gets an IO error reading an indirect block
- *             (ditto, *@err == -EIO)
- *     or when it reads all @depth-1 indirect blocks successfully and finds
- *     the whole chain, all way to the data (returns %NULL, *err == 0).
- *
- *      Need to be called with
- *      down_read(&EXT4_I(inode)->i_data_sem)
- */
-static Indirect *ext4_get_branch(struct inode *inode, int depth,
-                                ext4_lblk_t  *offsets,
-                                Indirect chain[4], int *err)
-{
-       struct super_block *sb = inode->i_sb;
-       Indirect *p = chain;
-       struct buffer_head *bh;
-
-       *err = 0;
-       /* i_data is not going away, no lock needed */
-       add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
-       if (!p->key)
-               goto no_block;
-       while (--depth) {
-               bh = sb_getblk(sb, le32_to_cpu(p->key));
-               if (unlikely(!bh))
-                       goto failure;
-
-               if (!bh_uptodate_or_lock(bh)) {
-                       if (bh_submit_read(bh) < 0) {
-                               put_bh(bh);
-                               goto failure;
-                       }
-                       /* validate block references */
-                       if (ext4_check_indirect_blockref(inode, bh)) {
-                               put_bh(bh);
-                               goto failure;
-                       }
-               }
-
-               add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
-               /* Reader: end */
-               if (!p->key)
-                       goto no_block;
-       }
-       return NULL;
-
-failure:
-       *err = -EIO;
-no_block:
-       return p;
-}
-
-/**
- *     ext4_find_near - find a place for allocation with sufficient locality
- *     @inode: owner
- *     @ind: descriptor of indirect block.
- *
- *     This function returns the preferred place for block allocation.
- *     It is used when heuristic for sequential allocation fails.
- *     Rules are:
- *       + if there is a block to the left of our position - allocate near it.
- *       + if pointer will live in indirect block - allocate near that block.
- *       + if pointer will live in inode - allocate in the same
- *         cylinder group.
- *
- * In the latter case we colour the starting block by the callers PID to
- * prevent it from clashing with concurrent allocations for a different inode
- * in the same block group.   The PID is used here so that functionally related
- * files will be close-by on-disk.
- *
- *     Caller must make sure that @ind is valid and will stay that way.
- */
-static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
-{
-       struct ext4_inode_info *ei = EXT4_I(inode);
-       __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
-       __le32 *p;
-       ext4_fsblk_t bg_start;
-       ext4_fsblk_t last_block;
-       ext4_grpblk_t colour;
-       ext4_group_t block_group;
-       int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
-
-       /* Try to find previous block */
-       for (p = ind->p - 1; p >= start; p--) {
-               if (*p)
-                       return le32_to_cpu(*p);
-       }
-
-       /* No such thing, so let's try location of indirect block */
-       if (ind->bh)
-               return ind->bh->b_blocknr;
-
-       /*
-        * It is going to be referred to from the inode itself? OK, just put it
-        * into the same cylinder group then.
-        */
-       block_group = ei->i_block_group;
-       if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
-               block_group &= ~(flex_size-1);
-               if (S_ISREG(inode->i_mode))
-                       block_group++;
-       }
-       bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
-       last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
-
-       /*
-        * If we are doing delayed allocation, we don't need take
-        * colour into account.
-        */
-       if (test_opt(inode->i_sb, DELALLOC))
-               return bg_start;
-
-       if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
-               colour = (current->pid % 16) *
-                       (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
-       else
-               colour = (current->pid % 16) * ((last_block - bg_start) / 16);
-       return bg_start + colour;
-}
-
-/**
- *     ext4_find_goal - find a preferred place for allocation.
- *     @inode: owner
- *     @block:  block we want
- *     @partial: pointer to the last triple within a chain
- *
- *     Normally this function find the preferred place for block allocation,
- *     returns it.
- *     Because this is only used for non-extent files, we limit the block nr
- *     to 32 bits.
- */
-static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
-                                  Indirect *partial)
-{
-       ext4_fsblk_t goal;
-
-       /*
-        * XXX need to get goal block from mballoc's data structures
-        */
-
-       goal = ext4_find_near(inode, partial);
-       goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
-       return goal;
-}
-
-/**
- *     ext4_blks_to_allocate - Look up the block map and count the number
- *     of direct blocks need to be allocated for the given branch.
- *
- *     @branch: chain of indirect blocks
- *     @k: number of blocks need for indirect blocks
- *     @blks: number of data blocks to be mapped.
- *     @blocks_to_boundary:  the offset in the indirect block
- *
- *     return the total number of blocks to be allocate, including the
- *     direct and indirect blocks.
- */
-static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
-                                int blocks_to_boundary)
-{
-       unsigned int count = 0;
-
-       /*
-        * Simple case, [t,d]Indirect block(s) has not allocated yet
-        * then it's clear blocks on that path have not allocated
-        */
-       if (k > 0) {
-               /* right now we don't handle cross boundary allocation */
-               if (blks < blocks_to_boundary + 1)
-                       count += blks;
-               else
-                       count += blocks_to_boundary + 1;
-               return count;
-       }
-
-       count++;
-       while (count < blks && count <= blocks_to_boundary &&
-               le32_to_cpu(*(branch[0].p + count)) == 0) {
-               count++;
-       }
-       return count;
-}
-
-/**
- *     ext4_alloc_blocks: multiple allocate blocks needed for a branch
- *     @handle: handle for this transaction
- *     @inode: inode which needs allocated blocks
- *     @iblock: the logical block to start allocated at
- *     @goal: preferred physical block of allocation
- *     @indirect_blks: the number of blocks need to allocate for indirect
- *                     blocks
- *     @blks: number of desired blocks
- *     @new_blocks: on return it will store the new block numbers for
- *     the indirect blocks(if needed) and the first direct block,
- *     @err: on return it will store the error code
- *
- *     This function will return the number of blocks allocated as
- *     requested by the passed-in parameters.
- */
-static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
-                            ext4_lblk_t iblock, ext4_fsblk_t goal,
-                            int indirect_blks, int blks,
-                            ext4_fsblk_t new_blocks[4], int *err)
-{
-       struct ext4_allocation_request ar;
-       int target, i;
-       unsigned long count = 0, blk_allocated = 0;
-       int index = 0;
-       ext4_fsblk_t current_block = 0;
-       int ret = 0;
-
-       /*
-        * Here we try to allocate the requested multiple blocks at once,
-        * on a best-effort basis.
-        * To build a branch, we should allocate blocks for
-        * the indirect blocks(if not allocated yet), and at least
-        * the first direct block of this branch.  That's the
-        * minimum number of blocks need to allocate(required)
-        */
-       /* first we try to allocate the indirect blocks */
-       target = indirect_blks;
-       while (target > 0) {
-               count = target;
-               /* allocating blocks for indirect blocks and direct blocks */
-               current_block = ext4_new_meta_blocks(handle, inode, goal,
-                                                    0, &count, err);
-               if (*err)
-                       goto failed_out;
-
-               if (unlikely(current_block + count > EXT4_MAX_BLOCK_FILE_PHYS)) {
-                       EXT4_ERROR_INODE(inode,
-                                        "current_block %llu + count %lu > %d!",
-                                        current_block, count,
-                                        EXT4_MAX_BLOCK_FILE_PHYS);
-                       *err = -EIO;
-                       goto failed_out;
-               }
-
-               target -= count;
-               /* allocate blocks for indirect blocks */
-               while (index < indirect_blks && count) {
-                       new_blocks[index++] = current_block++;
-                       count--;
-               }
-               if (count > 0) {
-                       /*
-                        * save the new block number
-                        * for the first direct block
-                        */
-                       new_blocks[index] = current_block;
-                       printk(KERN_INFO "%s returned more blocks than "
-                                               "requested\n", __func__);
-                       WARN_ON(1);
-                       break;
-               }
-       }
-
-       target = blks - count ;
-       blk_allocated = count;
-       if (!target)
-               goto allocated;
-       /* Now allocate data blocks */
-       memset(&ar, 0, sizeof(ar));
-       ar.inode = inode;
-       ar.goal = goal;
-       ar.len = target;
-       ar.logical = iblock;
-       if (S_ISREG(inode->i_mode))
-               /* enable in-core preallocation only for regular files */
-               ar.flags = EXT4_MB_HINT_DATA;
-
-       current_block = ext4_mb_new_blocks(handle, &ar, err);
-       if (unlikely(current_block + ar.len > EXT4_MAX_BLOCK_FILE_PHYS)) {
-               EXT4_ERROR_INODE(inode,
-                                "current_block %llu + ar.len %d > %d!",
-                                current_block, ar.len,
-                                EXT4_MAX_BLOCK_FILE_PHYS);
-               *err = -EIO;
-               goto failed_out;
-       }
-
-       if (*err && (target == blks)) {
-               /*
-                * if the allocation failed and we didn't allocate
-                * any blocks before
-                */
-               goto failed_out;
-       }
-       if (!*err) {
-               if (target == blks) {
-                       /*
-                        * save the new block number
-                        * for the first direct block
-                        */
-                       new_blocks[index] = current_block;
-               }
-               blk_allocated += ar.len;
-       }
-allocated:
-       /* total number of blocks allocated for direct blocks */
-       ret = blk_allocated;
-       *err = 0;
-       return ret;
-failed_out:
-       for (i = 0; i < index; i++)
-               ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
-       return ret;
-}
-
-/**
- *     ext4_alloc_branch - allocate and set up a chain of blocks.
- *     @handle: handle for this transaction
- *     @inode: owner
- *     @indirect_blks: number of allocated indirect blocks
- *     @blks: number of allocated direct blocks
- *     @goal: preferred place for allocation
- *     @offsets: offsets (in the blocks) to store the pointers to next.
- *     @branch: place to store the chain in.
- *
- *     This function allocates blocks, zeroes out all but the last one,
- *     links them into chain and (if we are synchronous) writes them to disk.
- *     In other words, it prepares a branch that can be spliced onto the
- *     inode. It stores the information about that chain in the branch[], in
- *     the same format as ext4_get_branch() would do. We are calling it after
- *     we had read the existing part of chain and partial points to the last
- *     triple of that (one with zero ->key). Upon the exit we have the same
- *     picture as after the successful ext4_get_block(), except that in one
- *     place chain is disconnected - *branch->p is still zero (we did not
- *     set the last link), but branch->key contains the number that should
- *     be placed into *branch->p to fill that gap.
- *
- *     If allocation fails we free all blocks we've allocated (and forget
- *     their buffer_heads) and return the error value the from failed
- *     ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
- *     as described above and return 0.
- */
-static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
-                            ext4_lblk_t iblock, int indirect_blks,
-                            int *blks, ext4_fsblk_t goal,
-                            ext4_lblk_t *offsets, Indirect *branch)
-{
-       int blocksize = inode->i_sb->s_blocksize;
-       int i, n = 0;
-       int err = 0;
-       struct buffer_head *bh;
-       int num;
-       ext4_fsblk_t new_blocks[4];
-       ext4_fsblk_t current_block;
-
-       num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
-                               *blks, new_blocks, &err);
-       if (err)
-               return err;
-
-       branch[0].key = cpu_to_le32(new_blocks[0]);
-       /*
-        * metadata blocks and data blocks are allocated.
-        */
-       for (n = 1; n <= indirect_blks;  n++) {
-               /*
-                * Get buffer_head for parent block, zero it out
-                * and set the pointer to new one, then send
-                * parent to disk.
-                */
-               bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
-               if (unlikely(!bh)) {
-                       err = -EIO;
-                       goto failed;
-               }
-
-               branch[n].bh = bh;
-               lock_buffer(bh);
-               BUFFER_TRACE(bh, "call get_create_access");
-               err = ext4_journal_get_create_access(handle, bh);
-               if (err) {
-                       /* Don't brelse(bh) here; it's done in
-                        * ext4_journal_forget() below */
-                       unlock_buffer(bh);
-                       goto failed;
-               }
-
-               memset(bh->b_data, 0, blocksize);
-               branch[n].p = (__le32 *) bh->b_data + offsets[n];
-               branch[n].key = cpu_to_le32(new_blocks[n]);
-               *branch[n].p = branch[n].key;
-               if (n == indirect_blks) {
-                       current_block = new_blocks[n];
-                       /*
-                        * End of chain, update the last new metablock of
-                        * the chain to point to the new allocated
-                        * data blocks numbers
-                        */
-                       for (i = 1; i < num; i++)
-                               *(branch[n].p + i) = cpu_to_le32(++current_block);
-               }
-               BUFFER_TRACE(bh, "marking uptodate");
-               set_buffer_uptodate(bh);
-               unlock_buffer(bh);
-
-               BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-               err = ext4_handle_dirty_metadata(handle, inode, bh);
-               if (err)
-                       goto failed;
-       }
-       *blks = num;
-       return err;
-failed:
-       /* Allocation failed, free what we already allocated */
-       ext4_free_blocks(handle, inode, NULL, new_blocks[0], 1, 0);
-       for (i = 1; i <= n ; i++) {
-               /*
-                * branch[i].bh is newly allocated, so there is no
-                * need to revoke the block, which is why we don't
-                * need to set EXT4_FREE_BLOCKS_METADATA.
-                */
-               ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1,
-                                EXT4_FREE_BLOCKS_FORGET);
-       }
-       for (i = n+1; i < indirect_blks; i++)
-               ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
-
-       ext4_free_blocks(handle, inode, NULL, new_blocks[i], num, 0);
-
-       return err;
-}
-
-/**
- * ext4_splice_branch - splice the allocated branch onto inode.
- * @handle: handle for this transaction
- * @inode: owner
- * @block: (logical) number of block we are adding
- * @chain: chain of indirect blocks (with a missing link - see
- *     ext4_alloc_branch)
- * @where: location of missing link
- * @num:   number of indirect blocks we are adding
- * @blks:  number of direct blocks we are adding
- *
- * This function fills the missing link and does all housekeeping needed in
- * inode (->i_blocks, etc.). In case of success we end up with the full
- * chain to new block and return 0.
- */
-static int ext4_splice_branch(handle_t *handle, struct inode *inode,
-                             ext4_lblk_t block, Indirect *where, int num,
-                             int blks)
-{
-       int i;
-       int err = 0;
-       ext4_fsblk_t current_block;
-
-       /*
-        * If we're splicing into a [td]indirect block (as opposed to the
-        * inode) then we need to get write access to the [td]indirect block
-        * before the splice.
-        */
-       if (where->bh) {
-               BUFFER_TRACE(where->bh, "get_write_access");
-               err = ext4_journal_get_write_access(handle, where->bh);
-               if (err)
-                       goto err_out;
-       }
-       /* That's it */
-
-       *where->p = where->key;
-
-       /*
-        * Update the host buffer_head or inode to point to more just allocated
-        * direct blocks blocks
-        */
-       if (num == 0 && blks > 1) {
-               current_block = le32_to_cpu(where->key) + 1;
-               for (i = 1; i < blks; i++)
-                       *(where->p + i) = cpu_to_le32(current_block++);
-       }
-
-       /* We are done with atomic stuff, now do the rest of housekeeping */
-       /* had we spliced it onto indirect block? */
-       if (where->bh) {
-               /*
-                * If we spliced it onto an indirect block, we haven't
-                * altered the inode.  Note however that if it is being spliced
-                * onto an indirect block at the very end of the file (the
-                * file is growing) then we *will* alter the inode to reflect
-                * the new i_size.  But that is not done here - it is done in
-                * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
-                */
-               jbd_debug(5, "splicing indirect only\n");
-               BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
-               err = ext4_handle_dirty_metadata(handle, inode, where->bh);
-               if (err)
-                       goto err_out;
-       } else {
-               /*
-                * OK, we spliced it into the inode itself on a direct block.
-                */
-               ext4_mark_inode_dirty(handle, inode);
-               jbd_debug(5, "splicing direct\n");
-       }
-       return err;
-
-err_out:
-       for (i = 1; i <= num; i++) {
-               /*
-                * branch[i].bh is newly allocated, so there is no
-                * need to revoke the block, which is why we don't
-                * need to set EXT4_FREE_BLOCKS_METADATA.
-                */
-               ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
-                                EXT4_FREE_BLOCKS_FORGET);
-       }
-       ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key),
-                        blks, 0);
-
-       return err;
-}
-
-/*
- * The ext4_ind_map_blocks() function handles non-extents inodes
- * (i.e., using the traditional indirect/double-indirect i_blocks
- * scheme) for ext4_map_blocks().
- *
- * Allocation strategy is simple: if we have to allocate something, we will
- * have to go the whole way to leaf. So let's do it before attaching anything
- * to tree, set linkage between the newborn blocks, write them if sync is
- * required, recheck the path, free and repeat if check fails, otherwise
- * set the last missing link (that will protect us from any truncate-generated
- * removals - all blocks on the path are immune now) and possibly force the
- * write on the parent block.
- * That has a nice additional property: no special recovery from the failed
- * allocations is needed - we simply release blocks and do not touch anything
- * reachable from inode.
- *
- * `handle' can be NULL if create == 0.
- *
- * return > 0, # of blocks mapped or allocated.
- * return = 0, if plain lookup failed.
- * return < 0, error case.
- *
- * The ext4_ind_get_blocks() function should be called with
- * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
- * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
- * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
- * blocks.
- */
-static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
-                              struct ext4_map_blocks *map,
-                              int flags)
-{
-       int err = -EIO;
-       ext4_lblk_t offsets[4];
-       Indirect chain[4];
-       Indirect *partial;
-       ext4_fsblk_t goal;
-       int indirect_blks;
-       int blocks_to_boundary = 0;
-       int depth;
-       int count = 0;
-       ext4_fsblk_t first_block = 0;
-
-       trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
-       J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
-       J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
-       depth = ext4_block_to_path(inode, map->m_lblk, offsets,
-                                  &blocks_to_boundary);
-
-       if (depth == 0)
-               goto out;
-
-       partial = ext4_get_branch(inode, depth, offsets, chain, &err);
-
-       /* Simplest case - block found, no allocation needed */
-       if (!partial) {
-               first_block = le32_to_cpu(chain[depth - 1].key);
-               count++;
-               /*map more blocks*/
-               while (count < map->m_len && count <= blocks_to_boundary) {
-                       ext4_fsblk_t blk;
-
-                       blk = le32_to_cpu(*(chain[depth-1].p + count));
-
-                       if (blk == first_block + count)
-                               count++;
-                       else
-                               break;
-               }
-               goto got_it;
-       }
-
-       /* Next simple case - plain lookup or failed read of indirect block */
-       if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
-               goto cleanup;
-
-       /*
-        * Okay, we need to do block allocation.
-       */
-       goal = ext4_find_goal(inode, map->m_lblk, partial);
-
-       /* the number of blocks need to allocate for [d,t]indirect blocks */
-       indirect_blks = (chain + depth) - partial - 1;
-
-       /*
-        * Next look up the indirect map to count the totoal number of
-        * direct blocks to allocate for this branch.
-        */
-       count = ext4_blks_to_allocate(partial, indirect_blks,
-                                     map->m_len, blocks_to_boundary);
-       /*
-        * Block out ext4_truncate while we alter the tree
-        */
-       err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
-                               &count, goal,
-                               offsets + (partial - chain), partial);
-
-       /*
-        * The ext4_splice_branch call will free and forget any buffers
-        * on the new chain if there is a failure, but that risks using
-        * up transaction credits, especially for bitmaps where the
-        * credits cannot be returned.  Can we handle this somehow?  We
-        * may need to return -EAGAIN upwards in the worst case.  --sct
-        */
-       if (!err)
-               err = ext4_splice_branch(handle, inode, map->m_lblk,
-                                        partial, indirect_blks, count);
-       if (err)
-               goto cleanup;
-
-       map->m_flags |= EXT4_MAP_NEW;
-
-       ext4_update_inode_fsync_trans(handle, inode, 1);
-got_it:
-       map->m_flags |= EXT4_MAP_MAPPED;
-       map->m_pblk = le32_to_cpu(chain[depth-1].key);
-       map->m_len = count;
-       if (count > blocks_to_boundary)
-               map->m_flags |= EXT4_MAP_BOUNDARY;
-       err = count;
-       /* Clean up and exit */
-       partial = chain + depth - 1;    /* the whole chain */
-cleanup:
-       while (partial > chain) {
-               BUFFER_TRACE(partial->bh, "call brelse");
-               brelse(partial->bh);
-               partial--;
-       }
-out:
-       trace_ext4_ind_map_blocks_exit(inode, map->m_lblk,
-                               map->m_pblk, map->m_len, err);
-       return err;
-}
-
 #ifdef CONFIG_QUOTA
 qsize_t *ext4_get_reserved_space(struct inode *inode)
 {
@@ -1014,32 +217,6 @@ qsize_t *ext4_get_reserved_space(struct inode *inode)
 
 /*
  * Calculate the number of metadata blocks need to reserve
- * to allocate a new block at @lblocks for non extent file based file
- */
-static int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock)
-{
-       struct ext4_inode_info *ei = EXT4_I(inode);
-       sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
-       int blk_bits;
-
-       if (lblock < EXT4_NDIR_BLOCKS)
-               return 0;
-
-       lblock -= EXT4_NDIR_BLOCKS;
-
-       if (ei->i_da_metadata_calc_len &&
-           (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
-               ei->i_da_metadata_calc_len++;
-               return 0;
-       }
-       ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
-       ei->i_da_metadata_calc_len = 1;
-       blk_bits = order_base_2(lblock);
-       return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
-}
-
-/*
- * Calculate the number of metadata blocks need to reserve
  * to allocate a block located at @lblock
  */
 static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
@@ -3380,114 +2557,6 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
 }
 
 /*
- * O_DIRECT for ext3 (or indirect map) based files
- *
- * If the O_DIRECT write will extend the file then add this inode to the
- * orphan list.  So recovery will truncate it back to the original size
- * if the machine crashes during the write.
- *
- * If the O_DIRECT write is intantiating holes inside i_size and the machine
- * crashes then stale disk data _may_ be exposed inside the file. But current
- * VFS code falls back into buffered path in that case so we are safe.
- */
-static ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
-                             const struct iovec *iov, loff_t offset,
-                             unsigned long nr_segs)
-{
-       struct file *file = iocb->ki_filp;
-       struct inode *inode = file->f_mapping->host;
-       struct ext4_inode_info *ei = EXT4_I(inode);
-       handle_t *handle;
-       ssize_t ret;
-       int orphan = 0;
-       size_t count = iov_length(iov, nr_segs);
-       int retries = 0;
-
-       if (rw == WRITE) {
-               loff_t final_size = offset + count;
-
-               if (final_size > inode->i_size) {
-                       /* Credits for sb + inode write */
-                       handle = ext4_journal_start(inode, 2);
-                       if (IS_ERR(handle)) {
-                               ret = PTR_ERR(handle);
-                               goto out;
-                       }
-                       ret = ext4_orphan_add(handle, inode);
-                       if (ret) {
-                               ext4_journal_stop(handle);
-                               goto out;
-                       }
-                       orphan = 1;
-                       ei->i_disksize = inode->i_size;
-                       ext4_journal_stop(handle);
-               }
-       }
-
-retry:
-       if (rw == READ && ext4_should_dioread_nolock(inode))
-               ret = __blockdev_direct_IO(rw, iocb, inode,
-                                inode->i_sb->s_bdev, iov,
-                                offset, nr_segs,
-                                ext4_get_block, NULL, NULL, 0);
-       else {
-               ret = blockdev_direct_IO(rw, iocb, inode,
-                                inode->i_sb->s_bdev, iov,
-                                offset, nr_segs,
-                                ext4_get_block, NULL);
-
-               if (unlikely((rw & WRITE) && ret < 0)) {
-                       loff_t isize = i_size_read(inode);
-                       loff_t end = offset + iov_length(iov, nr_segs);
-
-                       if (end > isize)
-                               ext4_truncate_failed_write(inode);
-               }
-       }
-       if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
-               goto retry;
-
-       if (orphan) {
-               int err;
-
-               /* Credits for sb + inode write */
-               handle = ext4_journal_start(inode, 2);
-               if (IS_ERR(handle)) {
-                       /* This is really bad luck. We've written the data
-                        * but cannot extend i_size. Bail out and pretend
-                        * the write failed... */
-                       ret = PTR_ERR(handle);
-                       if (inode->i_nlink)
-                               ext4_orphan_del(NULL, inode);
-
-                       goto out;
-               }
-               if (inode->i_nlink)
-                       ext4_orphan_del(handle, inode);
-               if (ret > 0) {
-                       loff_t end = offset + ret;
-                       if (end > inode->i_size) {
-                               ei->i_disksize = end;
-                               i_size_write(inode, end);
-                               /*
-                                * We're going to return a positive `ret'
-                                * here due to non-zero-length I/O, so there's
-                                * no way of reporting error returns from
-                                * ext4_mark_inode_dirty() to userspace.  So
-                                * ignore it.
-                                */
-                               ext4_mark_inode_dirty(handle, inode);
-                       }
-               }
-               err = ext4_journal_stop(handle);
-               if (ret == 0)
-                       ret = err;
-       }
-out:
-       return ret;
-}
-
-/*
  * ext4_get_block used when preparing for a DIO write or buffer write.
  * We allocate an uinitialized extent if blocks haven't been allocated.
  * The extent will be converted to initialized after the IO is complete.
@@ -3958,383 +3027,6 @@ unlock:
        return err;
 }
 
-/*
- * Probably it should be a library function... search for first non-zero word
- * or memcmp with zero_page, whatever is better for particular architecture.
- * Linus?
- */
-static inline int all_zeroes(__le32 *p, __le32 *q)
-{
-       while (p < q)
-               if (*p++)
-                       return 0;
-       return 1;
-}
-
-/**
- *     ext4_find_shared - find the indirect blocks for partial truncation.
- *     @inode:   inode in question
- *     @depth:   depth of the affected branch
- *     @offsets: offsets of pointers in that branch (see ext4_block_to_path)
- *     @chain:   place to store the pointers to partial indirect blocks
- *     @top:     place to the (detached) top of branch
- *
- *     This is a helper function used by ext4_truncate().
- *
- *     When we do truncate() we may have to clean the ends of several
- *     indirect blocks but leave the blocks themselves alive. Block is
- *     partially truncated if some data below the new i_size is referred
- *     from it (and it is on the path to the first completely truncated
- *     data block, indeed).  We have to free the top of that path along
- *     with everything to the right of the path. Since no allocation
- *     past the truncation point is possible until ext4_truncate()
- *     finishes, we may safely do the latter, but top of branch may
- *     require special attention - pageout below the truncation point
- *     might try to populate it.
- *
- *     We atomically detach the top of branch from the tree, store the
- *     block number of its root in *@top, pointers to buffer_heads of
- *     partially truncated blocks - in @chain[].bh and pointers to
- *     their last elements that should not be removed - in
- *     @chain[].p. Return value is the pointer to last filled element
- *     of @chain.
- *
- *     The work left to caller to do the actual freeing of subtrees:
- *             a) free the subtree starting from *@top
- *             b) free the subtrees whose roots are stored in
- *                     (@chain[i].p+1 .. end of @chain[i].bh->b_data)
- *             c) free the subtrees growing from the inode past the @chain[0].
- *                     (no partially truncated stuff there).  */
-
-static Indirect *ext4_find_shared(struct inode *inode, int depth,
-                                 ext4_lblk_t offsets[4], Indirect chain[4],
-                                 __le32 *top)
-{
-       Indirect *partial, *p;
-       int k, err;
-
-       *top = 0;
-       /* Make k index the deepest non-null offset + 1 */
-       for (k = depth; k > 1 && !offsets[k-1]; k--)
-               ;
-       partial = ext4_get_branch(inode, k, offsets, chain, &err);
-       /* Writer: pointers */
-       if (!partial)
-               partial = chain + k-1;
-       /*
-        * If the branch acquired continuation since we've looked at it -
-        * fine, it should all survive and (new) top doesn't belong to us.
-        */
-       if (!partial->key && *partial->p)
-               /* Writer: end */
-               goto no_top;
-       for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
-               ;
-       /*
-        * OK, we've found the last block that must survive. The rest of our
-        * branch should be detached before unlocking. However, if that rest
-        * of branch is all ours and does not grow immediately from the inode
-        * it's easier to cheat and just decrement partial->p.
-        */
-       if (p == chain + k - 1 && p > chain) {
-               p->p--;
-       } else {
-               *top = *p->p;
-               /* Nope, don't do this in ext4.  Must leave the tree intact */
-#if 0
-               *p->p = 0;
-#endif
-       }
-       /* Writer: end */
-
-       while (partial > p) {
-               brelse(partial->bh);
-               partial--;
-       }
-no_top:
-       return partial;
-}
-
-/*
- * Zero a number of block pointers in either an inode or an indirect block.
- * If we restart the transaction we must again get write access to the
- * indirect block for further modification.
- *
- * We release `count' blocks on disk, but (last - first) may be greater
- * than `count' because there can be holes in there.
- *
- * Return 0 on success, 1 on invalid block range
- * and < 0 on fatal error.
- */
-static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
-                            struct buffer_head *bh,
-                            ext4_fsblk_t block_to_free,
-                            unsigned long count, __le32 *first,
-                            __le32 *last)
-{
-       __le32 *p;
-       int     flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
-       int     err;
-
-       if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-               flags |= EXT4_FREE_BLOCKS_METADATA;
-
-       if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
-                                  count)) {
-               EXT4_ERROR_INODE(inode, "attempt to clear invalid "
-                                "blocks %llu len %lu",
-                                (unsigned long long) block_to_free, count);
-               return 1;
-       }
-
-       if (try_to_extend_transaction(handle, inode)) {
-               if (bh) {
-                       BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-                       err = ext4_handle_dirty_metadata(handle, inode, bh);
-                       if (unlikely(err))
-                               goto out_err;
-               }
-               err = ext4_mark_inode_dirty(handle, inode);
-               if (unlikely(err))
-                       goto out_err;
-               err = ext4_truncate_restart_trans(handle, inode,
-                                       ext4_blocks_for_truncate(inode));
-               if (unlikely(err))
-                       goto out_err;
-               if (bh) {
-                       BUFFER_TRACE(bh, "retaking write access");
-                       err = ext4_journal_get_write_access(handle, bh);
-                       if (unlikely(err))
-                               goto out_err;
-               }
-       }
-
-       for (p = first; p < last; p++)
-               *p = 0;
-
-       ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
-       return 0;
-out_err:
-       ext4_std_error(inode->i_sb, err);
-       return err;
-}
-
-/**
- * ext4_free_data - free a list of data blocks
- * @handle:    handle for this transaction
- * @inode:     inode we are dealing with
- * @this_bh:   indirect buffer_head which contains *@first and *@last
- * @first:     array of block numbers
- * @last:      points immediately past the end of array
- *
- * We are freeing all blocks referred from that array (numbers are stored as
- * little-endian 32-bit) and updating @inode->i_blocks appropriately.
- *
- * We accumulate contiguous runs of blocks to free.  Conveniently, if these
- * blocks are contiguous then releasing them at one time will only affect one
- * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
- * actually use a lot of journal space.
- *
- * @this_bh will be %NULL if @first and @last point into the inode's direct
- * block pointers.
- */
-static void ext4_free_data(handle_t *handle, struct inode *inode,
-                          struct buffer_head *this_bh,
-                          __le32 *first, __le32 *last)
-{
-       ext4_fsblk_t block_to_free = 0;    /* Starting block # of a run */
-       unsigned long count = 0;            /* Number of blocks in the run */
-       __le32 *block_to_free_p = NULL;     /* Pointer into inode/ind
-                                              corresponding to
-                                              block_to_free */
-       ext4_fsblk_t nr;                    /* Current block # */
-       __le32 *p;                          /* Pointer into inode/ind
-                                              for current block */
-       int err = 0;
-
-       if (this_bh) {                          /* For indirect block */
-               BUFFER_TRACE(this_bh, "get_write_access");
-               err = ext4_journal_get_write_access(handle, this_bh);
-               /* Important: if we can't update the indirect pointers
-                * to the blocks, we can't free them. */
-               if (err)
-                       return;
-       }
-
-       for (p = first; p < last; p++) {
-               nr = le32_to_cpu(*p);
-               if (nr) {
-                       /* accumulate blocks to free if they're contiguous */
-                       if (count == 0) {
-                               block_to_free = nr;
-                               block_to_free_p = p;
-                               count = 1;
-                       } else if (nr == block_to_free + count) {
-                               count++;
-                       } else {
-                               err = ext4_clear_blocks(handle, inode, this_bh,
-                                                       block_to_free, count,
-                                                       block_to_free_p, p);
-                               if (err)
-                                       break;
-                               block_to_free = nr;
-                               block_to_free_p = p;
-                               count = 1;
-                       }
-               }
-       }
-
-       if (!err && count > 0)
-               err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,
-                                       count, block_to_free_p, p);
-       if (err < 0)
-               /* fatal error */
-               return;
-
-       if (this_bh) {
-               BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
-
-               /*
-                * The buffer head should have an attached journal head at this
-                * point. However, if the data is corrupted and an indirect
-                * block pointed to itself, it would have been detached when
-                * the block was cleared. Check for this instead of OOPSing.
-                */
-               if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
-                       ext4_handle_dirty_metadata(handle, inode, this_bh);
-               else
-                       EXT4_ERROR_INODE(inode,
-                                        "circular indirect block detected at "
-                                        "block %llu",
-                               (unsigned long long) this_bh->b_blocknr);
-       }
-}
-
-/**
- *     ext4_free_branches - free an array of branches
- *     @handle: JBD handle for this transaction
- *     @inode: inode we are dealing with
- *     @parent_bh: the buffer_head which contains *@first and *@last
- *     @first: array of block numbers
- *     @last:  pointer immediately past the end of array
- *     @depth: depth of the branches to free
- *
- *     We are freeing all blocks referred from these branches (numbers are
- *     stored as little-endian 32-bit) and updating @inode->i_blocks
- *     appropriately.
- */
-static void ext4_free_branches(handle_t *handle, struct inode *inode,
-                              struct buffer_head *parent_bh,
-                              __le32 *first, __le32 *last, int depth)
-{
-       ext4_fsblk_t nr;
-       __le32 *p;
-
-       if (ext4_handle_is_aborted(handle))
-               return;
-
-       if (depth--) {
-               struct buffer_head *bh;
-               int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
-               p = last;
-               while (--p >= first) {
-                       nr = le32_to_cpu(*p);
-                       if (!nr)
-                               continue;               /* A hole */
-
-                       if (!ext4_data_block_valid(EXT4_SB(inode->i_sb),
-                                                  nr, 1)) {
-                               EXT4_ERROR_INODE(inode,
-                                                "invalid indirect mapped "
-                                                "block %lu (level %d)",
-                                                (unsigned long) nr, depth);
-                               break;
-                       }
-
-                       /* Go read the buffer for the next level down */
-                       bh = sb_bread(inode->i_sb, nr);
-
-                       /*
-                        * A read failure? Report error and clear slot
-                        * (should be rare).
-                        */
-                       if (!bh) {
-                               EXT4_ERROR_INODE_BLOCK(inode, nr,
-                                                      "Read failure");
-                               continue;
-                       }
-
-                       /* This zaps the entire block.  Bottom up. */
-                       BUFFER_TRACE(bh, "free child branches");
-                       ext4_free_branches(handle, inode, bh,
-                                       (__le32 *) bh->b_data,
-                                       (__le32 *) bh->b_data + addr_per_block,
-                                       depth);
-                       brelse(bh);
-
-                       /*
-                        * Everything below this this pointer has been
-                        * released.  Now let this top-of-subtree go.
-                        *
-                        * We want the freeing of this indirect block to be
-                        * atomic in the journal with the updating of the
-                        * bitmap block which owns it.  So make some room in
-                        * the journal.
-                        *
-                        * We zero the parent pointer *after* freeing its
-                        * pointee in the bitmaps, so if extend_transaction()
-                        * for some reason fails to put the bitmap changes and
-                        * the release into the same transaction, recovery
-                        * will merely complain about releasing a free block,
-                        * rather than leaking blocks.
-                        */
-                       if (ext4_handle_is_aborted(handle))
-                               return;
-                       if (try_to_extend_transaction(handle, inode)) {
-                               ext4_mark_inode_dirty(handle, inode);
-                               ext4_truncate_restart_trans(handle, inode,
-                                           ext4_blocks_for_truncate(inode));
-                       }
-
-                       /*
-                        * The forget flag here is critical because if
-                        * we are journaling (and not doing data
-                        * journaling), we have to make sure a revoke
-                        * record is written to prevent the journal
-                        * replay from overwriting the (former)
-                        * indirect block if it gets reallocated as a
-                        * data block.  This must happen in the same
-                        * transaction where the data blocks are
-                        * actually freed.
-                        */
-                       ext4_free_blocks(handle, inode, NULL, nr, 1,
-                                        EXT4_FREE_BLOCKS_METADATA|
-                                        EXT4_FREE_BLOCKS_FORGET);
-
-                       if (parent_bh) {
-                               /*
-                                * The block which we have just freed is
-                                * pointed to by an indirect block: journal it
-                                */
-                               BUFFER_TRACE(parent_bh, "get_write_access");
-                               if (!ext4_journal_get_write_access(handle,
-                                                                  parent_bh)){
-                                       *p = 0;
-                                       BUFFER_TRACE(parent_bh,
-                                       "call ext4_handle_dirty_metadata");
-                                       ext4_handle_dirty_metadata(handle,
-                                                                  inode,
-                                                                  parent_bh);
-                               }
-                       }
-               }
-       } else {
-               /* We have reached the bottom of the tree. */
-               BUFFER_TRACE(parent_bh, "free data blocks");
-               ext4_free_data(handle, inode, parent_bh, first, last);
-       }
-}
-
 int ext4_can_truncate(struct inode *inode)
 {
        if (S_ISREG(inode->i_mode))
@@ -4419,161 +3111,6 @@ void ext4_truncate(struct inode *inode)
        trace_ext4_truncate_exit(inode);
 }
 
-void ext4_ind_truncate(struct inode *inode)
-{
-       handle_t *handle;
-       struct ext4_inode_info *ei = EXT4_I(inode);
-       __le32 *i_data = ei->i_data;
-       int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
-       struct address_space *mapping = inode->i_mapping;
-       ext4_lblk_t offsets[4];
-       Indirect chain[4];
-       Indirect *partial;
-       __le32 nr = 0;
-       int n = 0;
-       ext4_lblk_t last_block, max_block;
-       unsigned blocksize = inode->i_sb->s_blocksize;
-
-       handle = start_transaction(inode);
-       if (IS_ERR(handle))
-               return;         /* AKPM: return what? */
-
-       last_block = (inode->i_size + blocksize-1)
-                                       >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
-       max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
-                                       >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
-
-       if (inode->i_size & (blocksize - 1))
-               if (ext4_block_truncate_page(handle, mapping, inode->i_size))
-                       goto out_stop;
-
-       if (last_block != max_block) {
-               n = ext4_block_to_path(inode, last_block, offsets, NULL);
-               if (n == 0)
-                       goto out_stop;  /* error */
-       }
-
-       /*
-        * OK.  This truncate is going to happen.  We add the inode to the
-        * orphan list, so that if this truncate spans multiple transactions,
-        * and we crash, we will resume the truncate when the filesystem
-        * recovers.  It also marks the inode dirty, to catch the new size.
-        *
-        * Implication: the file must always be in a sane, consistent
-        * truncatable state while each transaction commits.
-        */
-       if (ext4_orphan_add(handle, inode))
-               goto out_stop;
-
-       /*
-        * From here we block out all ext4_get_block() callers who want to
-        * modify the block allocation tree.
-        */
-       down_write(&ei->i_data_sem);
-
-       ext4_discard_preallocations(inode);
-
-       /*
-        * The orphan list entry will now protect us from any crash which
-        * occurs before the truncate completes, so it is now safe to propagate
-        * the new, shorter inode size (held for now in i_size) into the
-        * on-disk inode. We do this via i_disksize, which is the value which
-        * ext4 *really* writes onto the disk inode.
-        */
-       ei->i_disksize = inode->i_size;
-
-       if (last_block == max_block) {
-               /*
-                * It is unnecessary to free any data blocks if last_block is
-                * equal to the indirect block limit.
-                */
-               goto out_unlock;
-       } else if (n == 1) {            /* direct blocks */
-               ext4_free_data(handle, inode, NULL, i_data+offsets[0],
-                              i_data + EXT4_NDIR_BLOCKS);
-               goto do_indirects;
-       }
-
-       partial = ext4_find_shared(inode, n, offsets, chain, &nr);
-       /* Kill the top of shared branch (not detached) */
-       if (nr) {
-               if (partial == chain) {
-                       /* Shared branch grows from the inode */
-                       ext4_free_branches(handle, inode, NULL,
-                                          &nr, &nr+1, (chain+n-1) - partial);
-                       *partial->p = 0;
-                       /*
-                        * We mark the inode dirty prior to restart,
-                        * and prior to stop.  No need for it here.
-                        */
-               } else {
-                       /* Shared branch grows from an indirect block */
-                       BUFFER_TRACE(partial->bh, "get_write_access");
-                       ext4_free_branches(handle, inode, partial->bh,
-                                       partial->p,
-                                       partial->p+1, (chain+n-1) - partial);
-               }
-       }
-       /* Clear the ends of indirect blocks on the shared branch */
-       while (partial > chain) {
-               ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
-                                  (__le32*)partial->bh->b_data+addr_per_block,
-                                  (chain+n-1) - partial);
-               BUFFER_TRACE(partial->bh, "call brelse");
-               brelse(partial->bh);
-               partial--;
-       }
-do_indirects:
-       /* Kill the remaining (whole) subtrees */
-       switch (offsets[0]) {
-       default:
-               nr = i_data[EXT4_IND_BLOCK];
-               if (nr) {
-                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
-                       i_data[EXT4_IND_BLOCK] = 0;
-               }
-       case EXT4_IND_BLOCK:
-               nr = i_data[EXT4_DIND_BLOCK];
-               if (nr) {
-                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
-                       i_data[EXT4_DIND_BLOCK] = 0;
-               }
-       case EXT4_DIND_BLOCK:
-               nr = i_data[EXT4_TIND_BLOCK];
-               if (nr) {
-                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
-                       i_data[EXT4_TIND_BLOCK] = 0;
-               }
-       case EXT4_TIND_BLOCK:
-               ;
-       }
-
-out_unlock:
-       up_write(&ei->i_data_sem);
-       inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
-       ext4_mark_inode_dirty(handle, inode);
-
-       /*
-        * In a multi-transaction truncate, we only make the final transaction
-        * synchronous
-        */
-       if (IS_SYNC(inode))
-               ext4_handle_sync(handle);
-out_stop:
-       /*
-        * If this was a simple ftruncate(), and the file will remain alive
-        * then we need to clear up the orphan record which we created above.
-        * However, if this was a real unlink then we were called by
-        * ext4_delete_inode(), and we allow that function to clean up the
-        * orphan info for us.
-        */
-       if (inode->i_nlink)
-               ext4_orphan_del(handle, inode);
-
-       ext4_journal_stop(handle);
-       trace_ext4_truncate_exit(inode);
-}
-
 /*
  * ext4_get_inode_loc returns with an extra refcount against the inode's
  * underlying buffer_head on success. If 'in_mem' is true, we have all
@@ -5386,29 +3923,6 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
        return 0;
 }
 
-static int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk)
-{
-       int indirects;
-
-       /* if nrblocks are contiguous */
-       if (chunk) {
-               /*
-                * With N contiguous data blocks, we need at most
-                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
-                * 2 dindirect blocks, and 1 tindirect block
-                */
-               return DIV_ROUND_UP(nrblocks,
-                                   EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
-       }
-       /*
-        * if nrblocks are not contiguous, worse case, each block touch
-        * a indirect block, and each indirect block touch a double indirect
-        * block, plus a triple indirect block
-        */
-       indirects = nrblocks * 2 + 1;
-       return indirects;
-}
-
 static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
 {
        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))