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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Qilin Tan <qilin.tan@mediatek.com>,
	Chao Yu <chao@kernel.org>,
	Jaegeuk Kim <jaegeuk@kernel.org>,
	Daniel Rosenberg <drosen@google.com>
Subject: [PATCH 5.15 09/91] f2fs: fix iostat lock protection
Date: Mon, 12 Jun 2023 12:25:58 +0200
Message-ID: <20230612101702.474354291@linuxfoundation.org>
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From: Qilin Tan <qilin.tan@mediatek.com>

commit 144f1cd40bf91fb3ac1d41806470756ce774f389 upstream.

Made iostat lock irq safe to avoid potentinal deadlock.

Deadlock scenario:
f2fs_attr_store
  -> f2fs_sbi_store
  -> _sbi_store
  -> spin_lock(sbi->iostat_lock)
    <interrupt request>
    -> scsi_end_request
    -> bio_endio
    -> f2fs_dio_read_end_io
    -> f2fs_update_iostat
    -> spin_lock_irqsave(sbi->iostat_lock)  ===> Dead lock here

Fixes: 61803e984307 ("f2fs: fix iostat related lock protection")
Fixes: a1e09b03e6f5 ("f2fs: use iomap for direct I/O")
Signed-off-by: Qilin Tan <qilin.tan@mediatek.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/f2fs/sysfs.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -491,9 +491,9 @@ out:
 	if (!strcmp(a->attr.name, "iostat_period_ms")) {
 		if (t < MIN_IOSTAT_PERIOD_MS || t > MAX_IOSTAT_PERIOD_MS)
 			return -EINVAL;
-		spin_lock(&sbi->iostat_lock);
+		spin_lock_irq(&sbi->iostat_lock);
 		sbi->iostat_period_ms = (unsigned int)t;
-		spin_unlock(&sbi->iostat_lock);
+		spin_unlock_irq(&sbi->iostat_lock);
 		return count;
 	}
 #endif