From: Baokun Li <libaokun1@xxxxxxxxxx>
In ext4_io_end_defer_completion(), check if io_end->list_vec is empty to
avoid adding an io_end that requires no conversion to the
i_rsv_conversion_list, which in turn prevents starting an unnecessary
worker. An ext4_emergency_state() check is also added to avoid attempting
to abort the journal in an emergency state.
Additionally, ext4_put_io_end_defer() is refactored to call
ext4_io_end_defer_completion() directly instead of being open-coded.
This also prevents starting an unnecessary worker when EXT4_IO_END_FAILED
is set but data_err=abort is not enabled.
This ensures that the check in ext4_put_io_end_defer() is consistent with
the check in ext4_end_bio(). Otherwise, we might add an io_end to the
i_rsv_conversion_list and then call ext4_finish_bio(), after which the
inode could be freed before ext4_end_io_rsv_work() is called, triggering
a use-after-free issue.
Fixes: ce51afb8cc5e ("ext4: abort journal on data writeback failure if in data_err=abort mode")
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
---
fs/ext4/page-io.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 179e54f3a3b6..3d8b0f6d2dea 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -236,10 +236,12 @@ static void dump_completed_IO(struct inode *inode, struct list_head *head)
static bool ext4_io_end_defer_completion(ext4_io_end_t *io_end)
{
- if (io_end->flag & EXT4_IO_END_UNWRITTEN)
+ if (io_end->flag & EXT4_IO_END_UNWRITTEN &&
+ !list_empty(&io_end->list_vec))
return true;
if (test_opt(io_end->inode->i_sb, DATA_ERR_ABORT) &&
- io_end->flag & EXT4_IO_END_FAILED)
+ io_end->flag & EXT4_IO_END_FAILED &&
+ !ext4_emergency_state(io_end->inode->i_sb))
return true;
return false;
}
@@ -256,6 +258,7 @@ static void ext4_add_complete_io(ext4_io_end_t *io_end)
WARN_ON(!(io_end->flag & EXT4_IO_END_DEFER_COMPLETION));
WARN_ON(io_end->flag & EXT4_IO_END_UNWRITTEN &&
!io_end->handle && sbi->s_journal);
+ WARN_ON(!io_end->bio);
spin_lock_irqsave(&ei->i_completed_io_lock, flags);
wq = sbi->rsv_conversion_wq;
@@ -318,12 +321,9 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
void ext4_put_io_end_defer(ext4_io_end_t *io_end)
{
if (refcount_dec_and_test(&io_end->count)) {
- if (io_end->flag & EXT4_IO_END_FAILED ||
- (io_end->flag & EXT4_IO_END_UNWRITTEN &&
- !list_empty(&io_end->list_vec))) {
- ext4_add_complete_io(io_end);
- return;
- }
+ if (ext4_io_end_defer_completion(io_end))
+ return ext4_add_complete_io(io_end);
+
ext4_release_io_end(io_end);
}
}
--
2.46.1
