From 280227a75b56ab5d35854f3a77ef74a7ad56a203 Mon Sep 17 00:00:00 2001 From: Davide Italiano Date: Sat, 2 May 2015 23:21:15 -0400 Subject: [PATCH] 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 Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/extents.c | 15 ++++++++------- 1 file 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; -- 2.20.1