[PATCH 2/2] ext4: mark fc as ineligible using an handle in ext4_xattr_set()

From: Luis Henriques (SUSE)
Date: Thu Sep 19 2024 - 05:40:38 EST


Calling ext4_fc_mark_ineligible() with a NULL handle is racy and may result
in a fast-commit being done before the filesystem is effectively marked as
ineligible. This patch reduces the risk of this happening in function
ext4_xattr_set() by using an handle if one is available.

Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Luis Henriques (SUSE) <luis.henriques@xxxxxxxxx>
---
fs/ext4/xattr.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 46ce2f21fef9..dbe4d11cd332 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2554,11 +2554,15 @@ ext4_xattr_set(struct inode *inode, int name_index, const char *name,
handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
if (IS_ERR(handle)) {
error = PTR_ERR(handle);
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR,
+ NULL);
} else {
int error2;

error = ext4_xattr_set_handle(handle, inode, name_index, name,
value, value_len, flags);
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR,
+ handle);
error2 = ext4_journal_stop(handle);
if (error == -ENOSPC &&
ext4_should_retry_alloc(sb, &retries))
@@ -2566,7 +2570,6 @@ ext4_xattr_set(struct inode *inode, int name_index, const char *name,
if (error == 0)
error = error2;
}
- ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);

return error;
}