Cleanup macros for distinguishing mandatory locks
The combination of S_ISGID bit set and S_IXGRP bit unset is used to mark the
inode as "mandatory lockable" and there's a macro for this check called
MANDATORY_LOCK(inode). However, fs/locks.c and some filesystems still perform
the explicit i_mode checking. Besides, Andrew pointed out, that this macro is
buggy itself, as it dereferences the inode arg twice.
Convert this macro into static inline function and switch its users to it,
making the code shorter and more readable.
The __mandatory_lock() helper is to be used in places where the IS_MANDLOCK()
for superblock is already known to be true.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/fs/locks.c b/fs/locks.c
index 43dbc7f..9a3fe0d 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1119,7 +1119,7 @@
* If we've been sleeping someone might have
* changed the permissions behind our back.
*/
- if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
+ if (__mandatory_lock(inode))
continue;
}
@@ -1761,9 +1761,7 @@
/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
*/
- if (IS_MANDLOCK(inode) &&
- (inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
- mapping_writably_mapped(filp->f_mapping)) {
+ if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
error = -EAGAIN;
goto out;
}
@@ -1887,9 +1885,7 @@
/* Don't allow mandatory locks on files that may be memory mapped
* and shared.
*/
- if (IS_MANDLOCK(inode) &&
- (inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
- mapping_writably_mapped(filp->f_mapping)) {
+ if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
error = -EAGAIN;
goto out;
}
@@ -2083,9 +2079,7 @@
out += sprintf(out, "%6s %s ",
(fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
(inode == NULL) ? "*NOINODE*" :
- (IS_MANDLOCK(inode) &&
- (inode->i_mode & (S_IXGRP | S_ISGID)) == S_ISGID) ?
- "MANDATORY" : "ADVISORY ");
+ mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
} else if (IS_FLOCK(fl)) {
if (fl->fl_type & LOCK_MAND) {
out += sprintf(out, "FLOCK MSNFS ");