diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2011-09-20 17:19:26 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-11-09 00:16:44 -0500 |
| commit | 27ac0ffeac80ba6b9580529568d06144df044366 (patch) | |
| tree | a2e523716039784271250387d6e94ec4f01daec5 /fs/attr.c | |
| parent | 146a8595c6399ee6ab4b5cc34c0d28aa4835fdc5 (diff) | |
| download | linux-27ac0ffeac80ba6b9580529568d06144df044366.tar.bz2 | |
locks: break delegations on any attribute modification
NFSv4 uses leases to guarantee that clients can cache metadata as well
as data.
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/attr.c')
| -rw-r--r-- | fs/attr.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/fs/attr.c b/fs/attr.c index 1449adb14ef6..267968d94673 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -167,7 +167,27 @@ void setattr_copy(struct inode *inode, const struct iattr *attr) } EXPORT_SYMBOL(setattr_copy); -int notify_change(struct dentry * dentry, struct iattr * attr) +/** + * notify_change - modify attributes of a filesytem object + * @dentry: object affected + * @iattr: new attributes + * @delegated_inode: returns inode, if the inode is delegated + * + * The caller must hold the i_mutex on the affected object. + * + * If notify_change discovers a delegation in need of breaking, + * it will return -EWOULDBLOCK and return a reference to the inode in + * delegated_inode. The caller should then break the delegation and + * retry. Because breaking a delegation may take a long time, the + * caller should drop the i_mutex before doing so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. Also, passing NULL is fine for callers holding + * the file open for write, as there can be no conflicting delegation in + * that case. + */ +int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode) { struct inode *inode = dentry->d_inode; umode_t mode = inode->i_mode; @@ -243,6 +263,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr) error = security_inode_setattr(dentry, attr); if (error) return error; + error = try_break_deleg(inode, delegated_inode); + if (error) + return error; if (inode->i_op->setattr) error = inode->i_op->setattr(dentry, attr); |