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authorLinus Torvalds <torvalds@linux-foundation.org>2022-04-20 12:35:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-20 12:35:20 -0700
commit10c5f102e2be6d816938b168104e8dacdd5bace7 (patch)
tree21588bea76256e12c4b0a5031ed71c595329950e
parent906f904097359d059623ca8d3511d9f341080f2c (diff)
parent8b1ac84dcf2cf0fc86f29e92e5c63c4862de6e55 (diff)
Merge tag 'erofs-for-5.18-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs fixes from Gao Xiang: "One patch to fix a use-after-free race related to the on-stack z_erofs_decompressqueue, which happens very rarely but needs to be fixed properly soon. The other patch fixes some sysfs Sphinx warnings" * tag 'erofs-for-5.18-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: Documentation/ABI: sysfs-fs-erofs: Fix Sphinx errors erofs: fix use-after-free of on-stack io[]
-rw-r--r--Documentation/ABI/testing/sysfs-fs-erofs5
-rw-r--r--fs/erofs/zdata.c12
-rw-r--r--fs/erofs/zdata.h2
3 files changed, 8 insertions, 11 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-erofs b/Documentation/ABI/testing/sysfs-fs-erofs
index 05482374a741..bb4681a01811 100644
--- a/Documentation/ABI/testing/sysfs-fs-erofs
+++ b/Documentation/ABI/testing/sysfs-fs-erofs
@@ -9,8 +9,9 @@ Description: Shows all enabled kernel features.
What: /sys/fs/erofs/<disk>/sync_decompress
Date: November 2021
Contact: "Huang Jianan" <huangjianan@oppo.com>
-Description: Control strategy of sync decompression
+Description: Control strategy of sync decompression:
+
- 0 (default, auto): enable for readpage, and enable for
- readahead on atomic contexts only,
+ readahead on atomic contexts only.
- 1 (force on): enable for readpage and readahead.
- 2 (force off): disable for all situations.
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 0ed880f42525..e6dea6dfca16 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1066,12 +1066,9 @@ static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io,
/* wake up the caller thread for sync decompression */
if (sync) {
- unsigned long flags;
-
- spin_lock_irqsave(&io->u.wait.lock, flags);
if (!atomic_add_return(bios, &io->pending_bios))
- wake_up_locked(&io->u.wait);
- spin_unlock_irqrestore(&io->u.wait.lock, flags);
+ complete(&io->u.done);
+
return;
}
@@ -1217,7 +1214,7 @@ jobqueue_init(struct super_block *sb,
} else {
fg_out:
q = fgq;
- init_waitqueue_head(&fgq->u.wait);
+ init_completion(&fgq->u.done);
atomic_set(&fgq->pending_bios, 0);
}
q->sb = sb;
@@ -1419,8 +1416,7 @@ static void z_erofs_runqueue(struct super_block *sb,
return;
/* wait until all bios are completed */
- io_wait_event(io[JQ_SUBMIT].u.wait,
- !atomic_read(&io[JQ_SUBMIT].pending_bios));
+ wait_for_completion_io(&io[JQ_SUBMIT].u.done);
/* handle synchronous decompress queue in the caller context */
z_erofs_decompress_queue(&io[JQ_SUBMIT], pagepool);
diff --git a/fs/erofs/zdata.h b/fs/erofs/zdata.h
index e043216b545f..800b11c53f57 100644
--- a/fs/erofs/zdata.h
+++ b/fs/erofs/zdata.h
@@ -97,7 +97,7 @@ struct z_erofs_decompressqueue {
z_erofs_next_pcluster_t head;
union {
- wait_queue_head_t wait;
+ struct completion done;
struct work_struct work;
} u;
};