From 36673344b41c31fb502dd0d0113cec1aa96f581e Mon Sep 17 00:00:00 2001 From: ethanwu Date: Thu, 25 Sep 2025 18:42:05 +0800 Subject: ceph: supply snapshot context in ceph_zero_partial_object() [ Upstream commit f16bd3fa74a2084ee7e16a8a2be7e7399b970907 ] The ceph_zero_partial_object function was missing proper snapshot context for its OSD write operations, which could lead to data inconsistencies in snapshots. Reproducer: ../src/vstart.sh --new -x --localhost --bluestore ./bin/ceph auth caps client.fs_a mds 'allow rwps fsname=a' mon 'allow r fsname=a' osd 'allow rw tag cephfs data=a' mount -t ceph fs_a@.a=/ /mnt/mycephfs/ -o conf=./ceph.conf dd if=/dev/urandom of=/mnt/mycephfs/foo bs=64K count=1 mkdir /mnt/mycephfs/.snap/snap1 md5sum /mnt/mycephfs/.snap/snap1/foo fallocate -p -o 0 -l 4096 /mnt/mycephfs/foo echo 3 > /proc/sys/vm/drop/caches md5sum /mnt/mycephfs/.snap/snap1/foo # get different md5sum!! Cc: stable@vger.kernel.org Fixes: ad7a60de882ac ("ceph: punch hole support") Signed-off-by: ethanwu Reviewed-by: Viacheslav Dubeyko Tested-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/file.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index c1eafff45b19..e08805426c80 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1992,6 +1992,7 @@ static int ceph_zero_partial_object(struct inode *inode, struct ceph_inode_info *ci = ceph_inode(inode); struct ceph_fs_client *fsc = ceph_inode_to_client(inode); struct ceph_osd_request *req; + struct ceph_snap_context *snapc; int ret = 0; loff_t zero = 0; int op; @@ -2003,12 +2004,25 @@ static int ceph_zero_partial_object(struct inode *inode, op = CEPH_OSD_OP_ZERO; } + spin_lock(&ci->i_ceph_lock); + if (__ceph_have_pending_cap_snap(ci)) { + struct ceph_cap_snap *capsnap = + list_last_entry(&ci->i_cap_snaps, + struct ceph_cap_snap, + ci_item); + snapc = ceph_get_snap_context(capsnap->context); + } else { + BUG_ON(!ci->i_head_snapc); + snapc = ceph_get_snap_context(ci->i_head_snapc); + } + spin_unlock(&ci->i_ceph_lock); + req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, ceph_vino(inode), offset, length, 0, 1, op, CEPH_OSD_FLAG_WRITE, - NULL, 0, 0, false); + snapc, 0, 0, false); if (IS_ERR(req)) { ret = PTR_ERR(req); goto out; @@ -2024,6 +2038,7 @@ static int ceph_zero_partial_object(struct inode *inode, ceph_osdc_put_request(req); out: + ceph_put_snap_context(snapc); return ret; } -- cgit v1.2.3