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authorDavid Howells <dhowells@redhat.com>2022-05-21 08:18:28 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2022-05-22 09:25:47 -1000
commit2aeb8c86d49967552394d5e723f87454cb53f501 (patch)
tree2867b532960abfa1c5d2f99abfd93a0ea99cd76e
parent978df3e158467ae09be635b27e9e1eb990704e0b (diff)
afs: Fix afs_getattr() to refetch file status if callback break occurred
If a callback break occurs (change notification), afs_getattr() needs to issue an FS.FetchStatus RPC operation to update the status of the file being examined by the stat-family of system calls. Fix afs_getattr() to do this if AFS_VNODE_CB_PROMISED has been cleared on a vnode by a callback break. Skip this if AT_STATX_DONT_SYNC is set. This can be tested by appending to a file on one AFS client and then using "stat -L" to examine its length on a machine running kafs. This can also be watched through tracing on the kafs machine. The callback break is seen: kworker/1:1-46 [001] ..... 978.910812: afs_cb_call: c=0000005f YFSCB.CallBack kworker/1:1-46 [001] ...1. 978.910829: afs_cb_break: 100058:23b4c:242d2c2 b=2 s=1 break-cb kworker/1:1-46 [001] ..... 978.911062: afs_call_done: c=0000005f ret=0 ab=0 [0000000082994ead] And then the stat command generated no traffic if unpatched, but with this change a call to fetch the status can be observed: stat-4471 [000] ..... 986.744122: afs_make_fs_call: c=000000ab 100058:023b4c:242d2c2 YFS.FetchStatus stat-4471 [000] ..... 986.745578: afs_call_done: c=000000ab ret=0 ab=0 [0000000087fc8c84] Fixes: 08e0e7c82eea ("[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC.") Reported-by: Markus Suvanto <markus.suvanto@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Tested-by: Markus Suvanto <markus.suvanto@gmail.com> Tested-by: kafs-testing+fedora34_64checkkafs-build-496@auristor.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=216010 Link: https://lore.kernel.org/r/165308359800.162686.14122417881564420962.stgit@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/afs/inode.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 2fe402483ad5..30b066299d39 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -740,10 +740,22 @@ int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
{
struct inode *inode = d_inode(path->dentry);
struct afs_vnode *vnode = AFS_FS_I(inode);
- int seq = 0;
+ struct key *key;
+ int ret, seq = 0;
_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
+ if (!(query_flags & AT_STATX_DONT_SYNC) &&
+ !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
+ key = afs_request_key(vnode->volume->cell);
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+ ret = afs_validate(vnode, key);
+ key_put(key);
+ if (ret < 0)
+ return ret;
+ }
+
do {
read_seqbegin_or_lock(&vnode->cb_lock, &seq);
generic_fillattr(&init_user_ns, inode, stat);