ext4: Use bitops to read/modify EXT4_I(inode)->i_state
Theodore Ts'o [Sun, 24 Jan 2010 19:34:07 +0000 (14:34 -0500)]
At several places we modify EXT4_I(inode)->i_state without holding
i_mutex (ext4_release_file, ext4_bmap, ext4_journalled_writepage,
ext4_do_update_inode, ...). These modifications are racy and we can
lose updates to i_state. So convert handling of i_state to use bitops
which are atomic.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ext4.h
fs/ext4/extents.c
fs/ext4/file.c
fs/ext4/ialloc.c
fs/ext4/inode.c
fs/ext4/migrate.c
fs/ext4/xattr.c

index 307ecd1..ffe1334 100644 (file)
@@ -313,17 +313,6 @@ static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
                return flags & EXT4_OTHER_FLMASK;
 }
 
-/*
- * Inode dynamic state flags
- */
-#define EXT4_STATE_JDATA               0x00000001 /* journaled data exists */
-#define EXT4_STATE_NEW                 0x00000002 /* inode is newly created */
-#define EXT4_STATE_XATTR               0x00000004 /* has in-inode xattrs */
-#define EXT4_STATE_NO_EXPAND           0x00000008 /* No space for expansion */
-#define EXT4_STATE_DA_ALLOC_CLOSE      0x00000010 /* Alloc DA blks on close */
-#define EXT4_STATE_EXT_MIGRATE         0x00000020 /* Inode is migrating */
-#define EXT4_STATE_DIO_UNWRITTEN       0x00000040 /* need convert on dio done*/
-
 /* Used to pass group descriptor data when online resize is done */
 struct ext4_new_group_input {
        __u32 group;            /* Group number for this data */
@@ -631,7 +620,7 @@ struct ext4_inode_info {
         * near to their parent directory's inode.
         */
        ext4_group_t    i_block_group;
-       __u32   i_state;                /* Dynamic state flags for ext4 */
+       unsigned long   i_state_flags;          /* Dynamic state flags */
 
        ext4_lblk_t             i_dir_start_lookup;
 #ifdef CONFIG_EXT4_FS_XATTR
@@ -1051,6 +1040,34 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
                (ino >= EXT4_FIRST_INO(sb) &&
                 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
 }
+
+/*
+ * Inode dynamic state flags
+ */
+enum {
+       EXT4_STATE_JDATA,               /* journaled data exists */
+       EXT4_STATE_NEW,                 /* inode is newly created */
+       EXT4_STATE_XATTR,               /* has in-inode xattrs */
+       EXT4_STATE_NO_EXPAND,           /* No space for expansion */
+       EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
+       EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
+       EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
+};
+
+static inline int ext4_test_inode_state(struct inode *inode, int bit)
+{
+       return test_bit(bit, &EXT4_I(inode)->i_state_flags);
+}
+
+static inline void ext4_set_inode_state(struct inode *inode, int bit)
+{
+       set_bit(bit, &EXT4_I(inode)->i_state_flags);
+}
+
+static inline void ext4_clear_inode_state(struct inode *inode, int bit)
+{
+       clear_bit(bit, &EXT4_I(inode)->i_state_flags);
+}
 #else
 /* Assume that user mode programs are passing in an ext4fs superblock, not
  * a kernel struct super_block.  This will allow us to call the feature-test
index c568779..5461615 100644 (file)
@@ -3076,7 +3076,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
                if (io)
                        io->flag = DIO_AIO_UNWRITTEN;
                else
-                       EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;
+                       ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
                goto out;
        }
        /* async DIO end_io complete, convert the filled extent to written */
@@ -3362,8 +3362,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                        if (io)
                                io->flag = DIO_AIO_UNWRITTEN;
                        else
-                               EXT4_I(inode)->i_state |=
-                                       EXT4_STATE_DIO_UNWRITTEN;;
+                               ext4_set_inode_state(inode,
+                                                    EXT4_STATE_DIO_UNWRITTEN);
                }
        }
        err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
@@ -3739,7 +3739,7 @@ static int ext4_xattr_fiemap(struct inode *inode,
        int error = 0;
 
        /* in-inode? */
-       if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
+       if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
                struct ext4_iloc iloc;
                int offset;     /* offset of xattr in inode */
 
index 9630583..f6071ce 100644 (file)
@@ -35,9 +35,9 @@
  */
 static int ext4_release_file(struct inode *inode, struct file *filp)
 {
-       if (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) {
+       if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
                ext4_alloc_da_blocks(inode);
-               EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE;
+               ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
        }
        /* if we are the last writer on the inode, drop the block reservation */
        if ((filp->f_mode & FMODE_WRITE) &&
index f3624ea..2fab5ad 100644 (file)
@@ -1029,7 +1029,8 @@ got:
        inode->i_generation = sbi->s_next_generation++;
        spin_unlock(&sbi->s_next_gen_lock);
 
-       ei->i_state = EXT4_STATE_NEW;
+       ei->i_state_flags = 0;
+       ext4_set_inode_state(inode, EXT4_STATE_NEW);
 
        ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
 
index 1a3d7b2..3e53011 100644 (file)
@@ -1307,7 +1307,7 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
                         * i_data's format changing.  Force the migrate
                         * to fail by clearing migrate flags
                         */
-                       EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
+                       ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
                }
 
                /*
@@ -1794,7 +1794,7 @@ static int ext4_journalled_write_end(struct file *file,
        new_i_size = pos + copied;
        if (new_i_size > inode->i_size)
                i_size_write(inode, pos+copied);
-       EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+       ext4_set_inode_state(inode, EXT4_STATE_JDATA);
        if (new_i_size > EXT4_I(inode)->i_disksize) {
                ext4_update_i_disksize(inode, new_i_size);
                ret2 = ext4_mark_inode_dirty(handle, inode);
@@ -2632,7 +2632,7 @@ static int __ext4_journalled_writepage(struct page *page,
                ret = err;
 
        walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
-       EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+       ext4_set_inode_state(inode, EXT4_STATE_JDATA);
 out:
        return ret;
 }
@@ -3303,7 +3303,8 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
                filemap_write_and_wait(mapping);
        }
 
-       if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
+       if (EXT4_JOURNAL(inode) &&
+           ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
                /*
                 * This is a REALLY heavyweight approach, but the use of
                 * bmap on dirty files is expected to be extremely rare:
@@ -3322,7 +3323,7 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
                 * everything they get.
                 */
 
-               EXT4_I(inode)->i_state &= ~EXT4_STATE_JDATA;
+               ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
                journal = EXT4_JOURNAL(inode);
                jbd2_journal_lock_updates(journal);
                err = jbd2_journal_flush(journal);
@@ -3790,8 +3791,8 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
                        ext4_free_io_end(iocb->private);
                        iocb->private = NULL;
-               } else if (ret > 0 && (EXT4_I(inode)->i_state &
-                                      EXT4_STATE_DIO_UNWRITTEN)) {
+               } else if (ret > 0 && ext4_test_inode_state(inode,
+                                               EXT4_STATE_DIO_UNWRITTEN)) {
                        int err;
                        /*
                         * for non AIO case, since the IO is already
@@ -3801,7 +3802,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                                                             offset, ret);
                        if (err < 0)
                                ret = err;
-                       EXT4_I(inode)->i_state &= ~EXT4_STATE_DIO_UNWRITTEN;
+                       ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
                }
                return ret;
        }
@@ -4457,7 +4458,7 @@ void ext4_truncate(struct inode *inode)
                return;
 
        if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
-               ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
+               ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
 
        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
                ext4_ext_truncate(inode);
@@ -4743,7 +4744,7 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
 {
        /* We have all inode data except xattrs in memory here. */
        return __ext4_get_inode_loc(inode, iloc,
-               !(EXT4_I(inode)->i_state & EXT4_STATE_XATTR));
+               !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
 }
 
 void ext4_set_inode_flags(struct inode *inode)
@@ -4837,7 +4838,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
        }
        inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
 
-       ei->i_state = 0;
+       ei->i_state_flags = 0;
        ei->i_dir_start_lookup = 0;
        ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
        /* We now have enough fields to check if the inode was active or not.
@@ -4920,7 +4921,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                                        EXT4_GOOD_OLD_INODE_SIZE +
                                        ei->i_extra_isize;
                        if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))
-                               ei->i_state |= EXT4_STATE_XATTR;
+                               ext4_set_inode_state(inode, EXT4_STATE_XATTR);
                }
        } else
                ei->i_extra_isize = 0;
@@ -5060,7 +5061,7 @@ static int ext4_do_update_inode(handle_t *handle,
 
        /* For fields not not tracking in the in-memory inode,
         * initialise them to zero for new inodes. */
-       if (ei->i_state & EXT4_STATE_NEW)
+       if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
                memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
 
        ext4_get_inode_flags(ei);
@@ -5156,7 +5157,7 @@ static int ext4_do_update_inode(handle_t *handle,
        rc = ext4_handle_dirty_metadata(handle, inode, bh);
        if (!err)
                err = rc;
-       ei->i_state &= ~EXT4_STATE_NEW;
+       ext4_clear_inode_state(inode, EXT4_STATE_NEW);
 
        ext4_update_inode_fsync_trans(handle, inode, 0);
 out_brelse:
@@ -5580,8 +5581,8 @@ static int ext4_expand_extra_isize(struct inode *inode,
        entry = IFIRST(header);
 
        /* No extended attributes present */
-       if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) ||
-               header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
+       if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
+           header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
                memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
                        new_extra_isize);
                EXT4_I(inode)->i_extra_isize = new_extra_isize;
@@ -5625,7 +5626,7 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
        err = ext4_reserve_inode_write(handle, inode, &iloc);
        if (ext4_handle_valid(handle) &&
            EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
-           !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
+           !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
                /*
                 * We need extra buffer credits since we may write into EA block
                 * with this same handle. If journal_extend fails, then it will
@@ -5639,7 +5640,8 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
                                                      sbi->s_want_extra_isize,
                                                      iloc, handle);
                        if (ret) {
-                               EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+                               ext4_set_inode_state(inode,
+                                                    EXT4_STATE_NO_EXPAND);
                                if (mnt_count !=
                                        le16_to_cpu(sbi->s_es->s_mnt_count)) {
                                        ext4_warning(inode->i_sb, __func__,
index 8141581..46a4101 100644 (file)
@@ -365,12 +365,12 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
         * happened after we started the migrate. We need to
         * fail the migrate
         */
-       if (!(EXT4_I(inode)->i_state & EXT4_STATE_EXT_MIGRATE)) {
+       if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
                retval = -EAGAIN;
                up_write(&EXT4_I(inode)->i_data_sem);
                goto err_out;
        } else
-               EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
+               ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
        /*
         * We have the extent map build with the tmp inode.
         * Now copy the i_data across
@@ -533,7 +533,7 @@ int ext4_ext_migrate(struct inode *inode)
         * allocation.
         */
        down_read((&EXT4_I(inode)->i_data_sem));
-       EXT4_I(inode)->i_state |= EXT4_STATE_EXT_MIGRATE;
+       ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
        up_read((&EXT4_I(inode)->i_data_sem));
 
        handle = ext4_journal_start(inode, 1);
index f3a2f7e..c619a7e 100644 (file)
@@ -267,7 +267,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
        void *end;
        int error;
 
-       if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
+       if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
                return -ENODATA;
        error = ext4_get_inode_loc(inode, &iloc);
        if (error)
@@ -396,7 +396,7 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
        void *end;
        int error;
 
-       if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
+       if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
                return 0;
        error = ext4_get_inode_loc(inode, &iloc);
        if (error)
@@ -908,7 +908,7 @@ ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
        is->s.base = is->s.first = IFIRST(header);
        is->s.here = is->s.first;
        is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
-       if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
+       if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
                error = ext4_xattr_check_names(IFIRST(header), is->s.end);
                if (error)
                        return error;
@@ -940,10 +940,10 @@ ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
        header = IHDR(inode, ext4_raw_inode(&is->iloc));
        if (!IS_LAST_ENTRY(s->first)) {
                header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
-               EXT4_I(inode)->i_state |= EXT4_STATE_XATTR;
+               ext4_set_inode_state(inode, EXT4_STATE_XATTR);
        } else {
                header->h_magic = cpu_to_le32(0);
-               EXT4_I(inode)->i_state &= ~EXT4_STATE_XATTR;
+               ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
        }
        return 0;
 }
@@ -986,8 +986,8 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
        if (strlen(name) > 255)
                return -ERANGE;
        down_write(&EXT4_I(inode)->xattr_sem);
-       no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND;
-       EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+       no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
+       ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
 
        error = ext4_get_inode_loc(inode, &is.iloc);
        if (error)
@@ -997,10 +997,10 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
        if (error)
                goto cleanup;
 
-       if (EXT4_I(inode)->i_state & EXT4_STATE_NEW) {
+       if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
                struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
                memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
-               EXT4_I(inode)->i_state &= ~EXT4_STATE_NEW;
+               ext4_clear_inode_state(inode, EXT4_STATE_NEW);
        }
 
        error = ext4_xattr_ibody_find(inode, &i, &is);
@@ -1052,7 +1052,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
                ext4_xattr_update_super_block(handle, inode->i_sb);
                inode->i_ctime = ext4_current_time(inode);
                if (!value)
-                       EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
+                       ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
                error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
                /*
                 * The bh is consumed by ext4_mark_iloc_dirty, even with
@@ -1067,7 +1067,7 @@ cleanup:
        brelse(is.iloc.bh);
        brelse(bs.bh);
        if (no_expand == 0)
-               EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
+               ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
        up_write(&EXT4_I(inode)->xattr_sem);
        return error;
 }