6.15-stable review patch. If anyone has any objections, please let me know.
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From: Baokun Li libaokun1@huawei.com
[ Upstream commit c678bdc998754589cea2e6afab9401d7d8312ac4 ]
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@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Reviewed-by: Jan Kara jack@suse.cz Link: https://patch.msgid.link/20250708111504.3208660-1-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- 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); } }