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authorDavid Howells <dhowells@redhat.com>2020-06-15 17:36:58 +0100
committerDavid Howells <dhowells@redhat.com>2020-06-16 22:00:28 +0100
commitb6489a49f7b71964e37978d6f89bbdbdb263f6f5 (patch)
treec39005ca5aae5612498872eb010380d529ae5811 /fs/afs/inode.c
parent7c295eec1e351003a8ca06c34f9e79336fa5b244 (diff)
afs: Fix silly rename
Fix AFS's silly rename by the following means: (1) Set the destination directory in afs_do_silly_rename() so as to avoid misbehaviour and indicate that the directory data version will increment by 1 so as to avoid warnings about unexpected changes in the DV. Also indicate that the ctime should be updated to avoid xfstest grumbling. (2) Note when the server indicates that a directory changed more than we expected (AFS_OPERATION_DIR_CONFLICT), indicating a conflict with a third party change, checking on successful completion of unlink and rename. The problem is that the FS.RemoveFile RPC op doesn't report the status of the unlinked file, though YFS.RemoveFile2 does. This can be mitigated by the assumption that if the directory DV cranked by exactly 1, we can be sure we removed one link from the file; further, ordinarily in AFS, files cannot be hardlinked across directories, so if we reduce nlink to 0, the file is deleted. However, if the directory DV jumps by more than 1, we cannot know if a third party intervened by adding or removing a link on the file we just removed a link from. The same also goes for any vnode that is at the destination of the FS.Rename RPC op. (3) Make afs_vnode_commit_status() apply the nlink drop inside the cb_lock section along with the other attribute updates if ->op_unlinked is set on the descriptor for the appropriate vnode. (4) Issue a follow up status fetch to the unlinked file in the event of a third party conflict that makes it impossible for us to know if we actually deleted the file or not. (5) Provide a flag, AFS_VNODE_SILLY_DELETED, to make afs_getattr() lie to the user about the nlink of a silly deleted file so that it appears as 0, not 1. Found with the generic/035 and generic/084 xfstests. Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs/inode.c')
-rw-r--r--fs/afs/inode.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index d5d0ae7b2b1e..1d13d2e882ad 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -284,16 +284,25 @@ void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *v
write_seqlock(&vnode->cb_lock);
if (vp->scb.have_error) {
+ /* A YFS server will return this from RemoveFile2 and AFS and
+ * YFS will return this from InlineBulkStatus.
+ */
if (vp->scb.status.abort_code == VNOVNODE) {
set_bit(AFS_VNODE_DELETED, &vnode->flags);
clear_nlink(&vnode->vfs_inode);
__afs_break_callback(vnode, afs_cb_break_for_deleted);
+ op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
}
- } else {
- if (vp->scb.have_status)
- afs_apply_status(op, vp);
+ } else if (vp->scb.have_status) {
+ afs_apply_status(op, vp);
if (vp->scb.have_cb)
afs_apply_callback(op, vp);
+ } else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
+ drop_nlink(&vnode->vfs_inode);
+ if (vnode->vfs_inode.i_nlink == 0) {
+ set_bit(AFS_VNODE_DELETED, &vnode->flags);
+ __afs_break_callback(vnode, afs_cb_break_for_deleted);
+ }
}
write_sequnlock(&vnode->cb_lock);
@@ -304,7 +313,7 @@ void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *v
static void afs_fetch_status_success(struct afs_operation *op)
{
- struct afs_vnode_param *vp = &op->file[0];
+ struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
struct afs_vnode *vnode = vp->vnode;
int ret;
@@ -318,7 +327,7 @@ static void afs_fetch_status_success(struct afs_operation *op)
}
}
-static const struct afs_operation_ops afs_fetch_status_operation = {
+const struct afs_operation_ops afs_fetch_status_operation = {
.issue_afs_rpc = afs_fs_fetch_status,
.issue_yfs_rpc = yfs_fs_fetch_status,
.success = afs_fetch_status_success,
@@ -729,6 +738,9 @@ int afs_getattr(const struct path *path, struct kstat *stat,
do {
read_seqbegin_or_lock(&vnode->cb_lock, &seq);
generic_fillattr(inode, stat);
+ if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
+ stat->nlink > 0)
+ stat->nlink -= 1;
} while (need_seqretry(&vnode->cb_lock, seq));
done_seqretry(&vnode->cb_lock, seq);