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| author | Yan, Zheng <zyan@redhat.com> | 2017-04-19 10:01:48 +0800 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2017-04-25 21:08:26 +0200 |
| commit | 8179a101eb5f4ef0ac9a915fcea9a9d3109efa90 (patch) | |
| tree | a0b54dda13c9eea85dad15d40d8e345aa2bcc68d | |
| parent | 5a7ad1146caa895ad718a534399e38bd2ba721b7 (diff) | |
| download | lwn-8179a101eb5f4ef0ac9a915fcea9a9d3109efa90.tar.gz lwn-8179a101eb5f4ef0ac9a915fcea9a9d3109efa90.zip | |
ceph: fix recursion between ceph_set_acl() and __ceph_setattr()
ceph_set_acl() calls __ceph_setattr() if the setacl operation needs
to modify inode's i_mode. __ceph_setattr() updates inode's i_mode,
then calls posix_acl_chmod().
The problem is that __ceph_setattr() calls posix_acl_chmod() before
sending the setattr request. The get_acl() call in posix_acl_chmod()
can trigger a getxattr request. The reply of the getxattr request
can restore inode's i_mode to its old value. The set_acl() call in
posix_acl_chmod() sees old value of inode's i_mode, so it calls
__ceph_setattr() again.
Cc: stable@vger.kernel.org # needs backporting for < 4.9
Link: http://tracker.ceph.com/issues/19688
Reported-by: Jerry Lee <leisurelysw24@gmail.com>
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
| -rw-r--r-- | fs/ceph/inode.c | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index d449e1c03cbd..d3119fe3ab45 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -2071,11 +2071,6 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr) if (inode_dirty_flags) __mark_inode_dirty(inode, inode_dirty_flags); - if (ia_valid & ATTR_MODE) { - err = posix_acl_chmod(inode, attr->ia_mode); - if (err) - goto out_put; - } if (mask) { req->r_inode = inode; @@ -2089,13 +2084,11 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr) ceph_cap_string(dirtied), mask); ceph_mdsc_put_request(req); - if (mask & CEPH_SETATTR_SIZE) - __ceph_do_pending_vmtruncate(inode); - ceph_free_cap_flush(prealloc_cf); - return err; -out_put: - ceph_mdsc_put_request(req); ceph_free_cap_flush(prealloc_cf); + + if (err >= 0 && (mask & CEPH_SETATTR_SIZE)) + __ceph_do_pending_vmtruncate(inode); + return err; } @@ -2114,7 +2107,12 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) if (err != 0) return err; - return __ceph_setattr(inode, attr); + err = __ceph_setattr(inode, attr); + + if (err >= 0 && (attr->ia_valid & ATTR_MODE)) + err = posix_acl_chmod(inode, attr->ia_mode); + + return err; } /* |