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author | Luis Henriques <lhenriques@suse.com> | 2020-05-18 19:47:26 +0200 |
---|---|---|
committer | Ilya Dryomov <idryomov@gmail.com> | 2020-06-01 13:22:53 +0200 |
commit | 878dabb64117406abd40977b87544d05bb3031fc (patch) | |
tree | 6c09bf97a88e26af7393a745455d62971d5f5cd7 /fs | |
parent | libceph, rbd: replace zero-length array with flexible-array (diff) | |
download | linux-878dabb64117406abd40977b87544d05bb3031fc.tar.xz linux-878dabb64117406abd40977b87544d05bb3031fc.zip |
ceph: don't return -ESTALE if there's still an open file
Similarly to commit 03f219041fdb ("ceph: check i_nlink while converting
a file handle to dentry"), this fixes another corner case with
name_to_handle_at/open_by_handle_at. The issue has been detected by
xfstest generic/467, when doing:
- name_to_handle_at("/cephfs/myfile")
- open("/cephfs/myfile")
- unlink("/cephfs/myfile")
- sync; sync;
- drop caches
- open_by_handle_at()
The call to open_by_handle_at should not fail because the file hasn't been
deleted yet (only unlinked) and we do have a valid handle to it. -ESTALE
shall be returned only if i_nlink is 0 *and* i_count is 1.
This patch also makes sure we have LINK caps before checking i_nlink.
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/ceph/export.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/ceph/export.c b/fs/ceph/export.c index 79dc06881e78..e088843a7734 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -172,9 +172,16 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino) static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) { struct inode *inode = __lookup_inode(sb, ino); + int err; + if (IS_ERR(inode)) return ERR_CAST(inode); - if (inode->i_nlink == 0) { + /* We need LINK caps to reliably check i_nlink */ + err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); + if (err) + return ERR_PTR(err); + /* -ESTALE if inode as been unlinked and no file is open */ + if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) { iput(inode); return ERR_PTR(-ESTALE); } |