The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 9d5c4f5c7a2c7677e1b3942772122b032c265aae # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025102053-joylessly-pony-8641@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9d5c4f5c7a2c7677e1b3942772122b032c265aae Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim jaegeuk@kernel.org Date: Tue, 7 Oct 2025 03:32:30 +0000 Subject: [PATCH] f2fs: fix wrong block mapping for multi-devices

Assuming the disk layout as below,

disk0: 0 --- 0x00035abfff disk1: 0x00035ac000 --- 0x00037abfff disk2: 0x00037ac000 --- 0x00037ebfff

and we want to read data from offset=13568 having len=128 across the block devices, we can illustrate the block addresses like below.

0 .. 0x00037ac000 ------------------- 0x00037ebfff, 0x00037ec000 ------- | ^ ^ ^ | fofs 0 13568 13568+128 | ------------------------------------------------------ | LBA 0x37e8aa9 0x37ebfa9 0x37ec029 --- map 0x3caa9 0x3ffa9

In this example, we should give the relative map of the target block device ranging from 0x3caa9 to 0x3ffa9 where the length should be calculated by 0x37ebfff + 1 - 0x37ebfa9.

In the below equation, however, map->m_pblk was supposed to be the original address instead of the one from the target block address.

- map->m_len = min(map->m_len, dev->end_blk + 1 - map->m_pblk);

Cc: stable@vger.kernel.org Fixes: 71f2c8206202 ("f2fs: multidevice: support direct IO") Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index ef38e62cda8f..775aa4f63aa3 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1497,8 +1497,8 @@ static bool f2fs_map_blocks_cached(struct inode *inode, struct f2fs_dev_info *dev = &sbi->devs[bidx];

map->m_bdev = dev->bdev; - map->m_pblk -= dev->start_blk; map->m_len = min(map->m_len, dev->end_blk + 1 - map->m_pblk); + map->m_pblk -= dev->start_blk; } else { map->m_bdev = inode->i_sb->s_bdev; }