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authorDavide Italiano <dccitaliano@gmail.com>2015-05-02 23:21:15 -0400
committerTheodore Ts'o <tytso@mit.edu>2015-05-02 23:21:15 -0400
commit280227a75b56ab5d35854f3a77ef74a7ad56a203 (patch)
tree376af76e1cc5edefe88deb6fc6ac7f0d0f83a794
parentd2dc317d564a46dfc683978a2e5a4f91434e9711 (diff)
downloadlinux-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.c15
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;