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| author | Davide Italiano <dccitaliano@gmail.com> | 2015-05-02 23:21:15 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2015-05-02 23:21:15 -0400 |
| commit | 280227a75b56ab5d35854f3a77ef74a7ad56a203 (patch) | |
| tree | 376af76e1cc5edefe88deb6fc6ac7f0d0f83a794 | |
| parent | d2dc317d564a46dfc683978a2e5a4f91434e9711 (diff) | |
| download | linux-280227a75b56ab5d35854f3a77ef74a7ad56a203.tar.bz2 | |
ext4: move check under lock scope to close a race.
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>
Cc: stable@vger.kernel.org
| -rw-r--r-- | fs/ext4/extents.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 973816bfe4a9..d74e08029643 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4927,13 +4927,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) if (ret) return ret; - /* - * currently supporting (pre)allocate mode for extent-based - * files _only_ - */ - if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) - return -EOPNOTSUPP; - if (mode & FALLOC_FL_COLLAPSE_RANGE) return ext4_collapse_range(inode, offset, len); @@ -4955,6 +4948,14 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) mutex_lock(&inode->i_mutex); + /* + * We only support preallocation for extent-based files only + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + ret = -EOPNOTSUPP; + goto out; + } + if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > i_size_read(inode)) { new_size = offset + len; |