Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm...
[linux-3.10.git] / fs / jffs2 / file.c
index 8279bf0..1506673 100644 (file)
@@ -1,18 +1,18 @@
 /*
  * JFFS2 -- Journalling Flash File System, Version 2.
  *
- * Copyright (C) 2001-2003 Red Hat, Inc.
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
  *
  * Created by David Woodhouse <dwmw2@infradead.org>
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: file.c,v 1.102 2005/07/06 12:13:09 dwmw2 Exp $
- *
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kernel.h>
-#include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/time.h>
 #include <linux/pagemap.h>
 #include <linux/jffs2.h>
 #include "nodelist.h"
 
-static int jffs2_commit_write (struct file *filp, struct page *pg,
-                              unsigned start, unsigned end);
-static int jffs2_prepare_write (struct file *filp, struct page *pg,
-                               unsigned start, unsigned end);
+static int jffs2_write_end(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned copied,
+                       struct page *pg, void *fsdata);
+static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned flags,
+                       struct page **pagep, void **fsdata);
 static int jffs2_readpage (struct file *filp, struct page *pg);
 
-int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 {
-       struct inode *inode = dentry->d_inode;
+       struct inode *inode = filp->f_mapping->host;
        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
+       int ret;
 
+       ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+       if (ret)
+               return ret;
+
+       mutex_lock(&inode->i_mutex);
        /* Trigger GC to flush any pending writes for this inode */
        jffs2_flush_wbuf_gc(c, inode->i_ino);
-                       
-       return 0;       
+       mutex_unlock(&inode->i_mutex);
+
+       return 0;
 }
 
-struct file_operations jffs2_file_operations =
+const struct file_operations jffs2_file_operations =
 {
        .llseek =       generic_file_llseek,
        .open =         generic_file_open,
-       .read =         generic_file_read,
-       .write =        generic_file_write,
-       .ioctl =        jffs2_ioctl,
+       .read =         do_sync_read,
+       .aio_read =     generic_file_aio_read,
+       .write =        do_sync_write,
+       .aio_write =    generic_file_aio_write,
+       .unlocked_ioctl=jffs2_ioctl,
        .mmap =         generic_file_readonly_mmap,
        .fsync =        jffs2_fsync,
-       .sendfile =     generic_file_sendfile
+       .splice_read =  generic_file_splice_read,
 };
 
 /* jffs2_file_inode_operations */
 
-struct inode_operations jffs2_file_inode_operations =
+const struct inode_operations jffs2_file_inode_operations =
 {
-       .setattr =      jffs2_setattr
+       .get_acl =      jffs2_get_acl,
+       .setattr =      jffs2_setattr,
+       .setxattr =     jffs2_setxattr,
+       .getxattr =     jffs2_getxattr,
+       .listxattr =    jffs2_listxattr,
+       .removexattr =  jffs2_removexattr
 };
 
-struct address_space_operations jffs2_file_address_operations =
+const struct address_space_operations jffs2_file_address_operations =
 {
        .readpage =     jffs2_readpage,
-       .prepare_write =jffs2_prepare_write,
-       .commit_write = jffs2_commit_write
+       .write_begin =  jffs2_write_begin,
+       .write_end =    jffs2_write_end,
 };
 
 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
@@ -71,7 +87,8 @@ static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
        unsigned char *pg_buf;
        int ret;
 
-       D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
+       jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n",
+                 __func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT);
 
        BUG_ON(!PageLocked(pg));
 
@@ -91,8 +108,8 @@ static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
        flush_dcache_page(pg);
        kunmap(pg);
 
-       D2(printk(KERN_DEBUG "readpage finished\n"));
-       return 0;
+       jffs2_dbg(2, "readpage finished\n");
+       return ret;
 }
 
 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
@@ -107,38 +124,53 @@ static int jffs2_readpage (struct file *filp, struct page *pg)
 {
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
        int ret;
-       
-       down(&f->sem);
+
+       mutex_lock(&f->sem);
        ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
-       up(&f->sem);
+       mutex_unlock(&f->sem);
        return ret;
 }
 
-static int jffs2_prepare_write (struct file *filp, struct page *pg,
-                               unsigned start, unsigned end)
+static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned flags,
+                       struct page **pagep, void **fsdata)
 {
-       struct inode *inode = pg->mapping->host;
+       struct page *pg;
+       struct inode *inode = mapping->host;
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
-       uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
+       struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
+       struct jffs2_raw_inode ri;
+       uint32_t alloc_len = 0;
+       pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+       uint32_t pageofs = index << PAGE_CACHE_SHIFT;
        int ret = 0;
 
-       D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
+       jffs2_dbg(1, "%s()\n", __func__);
 
        if (pageofs > inode->i_size) {
+               ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
+                                         ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
+               if (ret)
+                       return ret;
+       }
+
+       mutex_lock(&f->sem);
+       pg = grab_cache_page_write_begin(mapping, index, flags);
+       if (!pg) {
+               if (alloc_len)
+                       jffs2_complete_reservation(c);
+               mutex_unlock(&f->sem);
+               return -ENOMEM;
+       }
+       *pagep = pg;
+
+       if (alloc_len) {
                /* Make new hole frag from old EOF to new page */
-               struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
-               struct jffs2_raw_inode ri;
                struct jffs2_full_dnode *fn;
-               uint32_t phys_ofs, alloc_len;
-               
-               D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
-                         (unsigned int)inode->i_size, pageofs));
 
-               ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
-               if (ret)
-                       return ret;
+               jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
+                         (unsigned int)inode->i_size, pageofs);
 
-               down(&f->sem);
                memset(&ri, 0, sizeof(ri));
 
                ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
@@ -149,8 +181,8 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
                ri.ino = cpu_to_je32(f->inocache->ino);
                ri.version = cpu_to_je32(++f->highest_version);
                ri.mode = cpu_to_jemode(inode->i_mode);
-               ri.uid = cpu_to_je16(inode->i_uid);
-               ri.gid = cpu_to_je16(inode->i_gid);
+               ri.uid = cpu_to_je16(i_uid_read(inode));
+               ri.gid = cpu_to_je16(i_gid_read(inode));
                ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
                ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
                ri.offset = cpu_to_je32(inode->i_size);
@@ -159,14 +191,13 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
                ri.compr = JFFS2_COMPR_ZERO;
                ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
                ri.data_crc = cpu_to_je32(0);
-               
-               fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
+
+               fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
 
                if (IS_ERR(fn)) {
                        ret = PTR_ERR(fn);
                        jffs2_complete_reservation(c);
-                       up(&f->sem);
-                       return ret;
+                       goto out_page;
                }
                ret = jffs2_add_full_dnode_to_inode(c, f, fn);
                if (f->metadata) {
@@ -175,65 +206,88 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg,
                        f->metadata = NULL;
                }
                if (ret) {
-                       D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
+                       jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
+                                 ret);
                        jffs2_mark_node_obsolete(c, fn->raw);
                        jffs2_free_full_dnode(fn);
                        jffs2_complete_reservation(c);
-                       up(&f->sem);
-                       return ret;
+                       goto out_page;
                }
                jffs2_complete_reservation(c);
                inode->i_size = pageofs;
-               up(&f->sem);
        }
-       
-       /* Read in the page if it wasn't already present, unless it's a whole page */
-       if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
-               down(&f->sem);
+
+       /*
+        * Read in the page if it wasn't already present. Cannot optimize away
+        * the whole page write case until jffs2_write_end can handle the
+        * case of a short-copy.
+        */
+       if (!PageUptodate(pg)) {
                ret = jffs2_do_readpage_nolock(inode, pg);
-               up(&f->sem);
+               if (ret)
+                       goto out_page;
        }
-       D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
+       mutex_unlock(&f->sem);
+       jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
+       return ret;
+
+out_page:
+       unlock_page(pg);
+       page_cache_release(pg);
+       mutex_unlock(&f->sem);
        return ret;
 }
 
-static int jffs2_commit_write (struct file *filp, struct page *pg,
-                              unsigned start, unsigned end)
+static int jffs2_write_end(struct file *filp, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned copied,
+                       struct page *pg, void *fsdata)
 {
        /* Actually commit the write from the page cache page we're looking at.
         * For now, we write the full page out each time. It sucks, but it's simple
         */
-       struct inode *inode = pg->mapping->host;
+       struct inode *inode = mapping->host;
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
        struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
        struct jffs2_raw_inode *ri;
+       unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+       unsigned end = start + copied;
        unsigned aligned_start = start & ~3;
        int ret = 0;
        uint32_t writtenlen = 0;
 
-       D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
-                 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
-
-       if (!start && end == PAGE_CACHE_SIZE) {
-               /* We need to avoid deadlock with page_cache_read() in
-                  jffs2_garbage_collect_pass(). So we have to mark the
-                  page up to date, to prevent page_cache_read() from 
-                  trying to re-lock it. */
-               SetPageUptodate(pg);
+       jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
+                 __func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT,
+                 start, end, pg->flags);
+
+       /* We need to avoid deadlock with page_cache_read() in
+          jffs2_garbage_collect_pass(). So the page must be
+          up to date to prevent page_cache_read() from trying
+          to re-lock it. */
+       BUG_ON(!PageUptodate(pg));
+
+       if (end == PAGE_CACHE_SIZE) {
+               /* When writing out the end of a page, write out the
+                  _whole_ page. This helps to reduce the number of
+                  nodes in files which have many short writes, like
+                  syslog files. */
+               aligned_start = 0;
        }
 
        ri = jffs2_alloc_raw_inode();
 
        if (!ri) {
-               D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
+               jffs2_dbg(1, "%s(): Allocation of raw inode failed\n",
+                         __func__);
+               unlock_page(pg);
+               page_cache_release(pg);
                return -ENOMEM;
        }
 
        /* Set the fields that the generic jffs2_write_inode_range() code can't find */
        ri->ino = cpu_to_je32(inode->i_ino);
        ri->mode = cpu_to_jemode(inode->i_mode);
-       ri->uid = cpu_to_je16(inode->i_uid);
-       ri->gid = cpu_to_je16(inode->i_gid);
+       ri->uid = cpu_to_je16(i_uid_read(inode));
+       ri->gid = cpu_to_je16(i_gid_read(inode));
        ri->isize = cpu_to_je32((uint32_t)inode->i_size);
        ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
 
@@ -251,18 +305,15 @@ static int jffs2_commit_write (struct file *filp, struct page *pg,
                /* There was an error writing. */
                SetPageError(pg);
        }
-       
+
        /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
-       if (writtenlen < (start&3))
-               writtenlen = 0;
-       else
-               writtenlen -= (start&3);
+       writtenlen -= min(writtenlen, (start - aligned_start));
 
        if (writtenlen) {
-               if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
-                       inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
+               if (inode->i_size < pos + writtenlen) {
+                       inode->i_size = pos + writtenlen;
                        inode->i_blocks = (inode->i_size + 511) >> 9;
-                       
+
                        inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
                }
        }
@@ -271,13 +322,17 @@ static int jffs2_commit_write (struct file *filp, struct page *pg,
 
        if (start+writtenlen < end) {
                /* generic_file_write has written more to the page cache than we've
-                  actually written to the medium. Mark the page !Uptodate so that 
+                  actually written to the medium. Mark the page !Uptodate so that
                   it gets reread */
-               D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
+               jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n",
+                       __func__);
                SetPageError(pg);
                ClearPageUptodate(pg);
        }
 
-       D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret));
-       return writtenlen?writtenlen:ret;
+       jffs2_dbg(1, "%s() returning %d\n",
+                 __func__, writtenlen > 0 ? writtenlen : ret);
+       unlock_page(pg);
+       page_cache_release(pg);
+       return writtenlen > 0 ? writtenlen : ret;
 }