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| author | Sage Weil <sage@newdream.net> | 2010-03-30 22:54:41 +0200 |
|---|---|---|
| committer | Sage Weil <sage@newdream.net> | 2010-03-30 22:55:22 +0200 |
| commit | 9358c6d4c0264b1572554c49c4b92673ea9a5c72 (patch) | |
| tree | 3d11a5021487dccf61b8d53c66c32df6b84223eb /fs | |
| parent | Linux 2.6.34-rc3 (diff) | |
| download | linux-9358c6d4c0264b1572554c49c4b92673ea9a5c72.tar.xz linux-9358c6d4c0264b1572554c49c4b92673ea9a5c72.zip | |
ceph: fix dentry rehashing on virtual .snap dir
If a lookup fails on the magic .snap directory, we bind it to a magic
snap directory inode in ceph_lookup_finish(). That code assumes the dentry
is unhashed, but a recent server-side change started returning NULL leases
on lookup failure, causing the .snap dentry to be hashed and NULL by
ceph_fill_trace().
This causes dentry hash chain corruption, or a dies when d_rehash()
includes
BUG_ON(!d_unhashed(entry));
So, avoid processing the NULL dentry lease if it the dentry matches the
snapdir name in ceph_fill_trace(). That allows the lookup completion to
properly bind it to the snapdir inode. BUG there if dentry is hashed to
be sure.
Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ceph/dir.c | 1 | ||||
| -rw-r--r-- | fs/ceph/inode.c | 10 |
2 files changed, 10 insertions, 1 deletions
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 8a9116e15b70..aed8fda33024 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -488,6 +488,7 @@ struct dentry *ceph_finish_lookup(struct ceph_mds_request *req, struct inode *inode = ceph_get_snapdir(parent); dout("ENOENT on snapdir %p '%.*s', linking to snapdir %p\n", dentry, dentry->d_name.len, dentry->d_name.name, inode); + BUG_ON(!d_unhashed(dentry)); d_add(dentry, inode); err = 0; } diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index aca82d55cc53..26f883c275e8 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -886,6 +886,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, struct inode *in = NULL; struct ceph_mds_reply_inode *ininfo; struct ceph_vino vino; + struct ceph_client *client = ceph_sb_to_client(sb); int i = 0; int err = 0; @@ -949,7 +950,14 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, return err; } - if (rinfo->head->is_dentry && !req->r_aborted) { + /* + * ignore null lease/binding on snapdir ENOENT, or else we + * will have trouble splicing in the virtual snapdir later + */ + if (rinfo->head->is_dentry && !req->r_aborted && + (rinfo->head->is_target || strncmp(req->r_dentry->d_name.name, + client->mount_args->snapdir_name, + req->r_dentry->d_name.len))) { /* * lookup link rename : null -> possibly existing inode * mknod symlink mkdir : null -> new inode |