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| author | Davide Italiano <dccitaliano@gmail.com> | 2015-05-03 06:21:15 +0300 |
|---|---|---|
| committer | Zefan Li <lizefan@huawei.com> | 2015-09-18 04:20:35 +0300 |
| commit | 0c797892cfa290d60a425d863962d285801fee8b (patch) | |
| tree | f2a53925f3100d34bba08a189d5e205e730a1797 | |
| parent | c79a54264db288e0fc221a4f39981feea15447ab (diff) | |
| download | linux-0c797892cfa290d60a425d863962d285801fee8b.tar.xz | |
ext4: move check under lock scope to close a race.
commit 280227a75b56ab5d35854f3a77ef74a7ad56a203 upstream.
fallocate() checks that the file is extent-based and returns
EOPNOTSUPP in case is not. Other tasks can convert from and to
indirect and extent so it's safe to check only after grabbing
the inode mutex.
Signed-off-by: Davide Italiano <dccitaliano@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[lizf: Backported to 3.4:
- adjust context
- return -EOPNOTSUPP instead of jumping to the "out" label]
Signed-off-by: Zefan Li <lizefan@huawei.com>
| -rw-r--r-- | fs/ext4/extents.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 4296a6f800a0..bb72833e9455 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4365,13 +4365,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) struct ext4_map_blocks map; unsigned int credits, blkbits = inode->i_blkbits; - /* - * currently supporting (pre)allocate mode for extent-based - * files _only_ - */ - if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) - return -EOPNOTSUPP; - /* Return error if mode is not supported */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) return -EOPNOTSUPP; @@ -4392,6 +4385,15 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) */ credits = ext4_chunk_trans_blocks(inode, max_blocks); mutex_lock(&inode->i_mutex); + + /* + * We only support preallocation for extent-based files only + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + mutex_unlock(&inode->i_mutex); + return -EOPNOTSUPP; + } + ret = inode_newsize_ok(inode, (len + offset)); if (ret) { mutex_unlock(&inode->i_mutex); |