| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.0 55/72] ext4: move check under lock scope to close a race. | Date | Mon, 11 May 2015 10:55:01 -0700 |
| |
4.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Davide Italiano <dccitaliano@gmail.com>
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/ext4/extents.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
--- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4934,13 +4934,6 @@ long ext4_fallocate(struct file *file, i 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); @@ -4962,6 +4955,14 @@ long ext4_fallocate(struct file *file, i 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;
|