Commit 144f1cd4 authored by Qilin Tan's avatar Qilin Tan Committed by Jaegeuk Kim
Browse files

f2fs: fix iostat lock protection 



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: 61803e98 ("f2fs: fix iostat related lock protection")
Fixes: a1e09b03 ("f2fs: use iomap for direct I/O")
Signed-off-by: default avatarQilin Tan <qilin.tan@mediatek.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent f26aaee6

fs/f2fs/sysfs.c

+2 −2
Original line number Diff line number Diff line
@@ -575,9 +575,9 @@ static ssize_t __sbi_store(struct f2fs_attr *a, 
	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