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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-20 10:50:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-20 10:50:01 -0700
commit36231d255b8df9cb4698e9a3902c16067d5c1398 (patch)
tree78aac3506bce9984576c0bac23fe095c08b40550
parent19bf1c2c7b9f21b9fe86315c5758d26c3049c2ad (diff)
parent24924a20dab603089011f9d3eb7622f0f6ef93c0 (diff)
downloadlinux-sh-36231d255b8df9cb4698e9a3902c16067d5c1398.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro: "The sget() one is a long-standing bug and will need to go into -stable (in fact, it had been originally caught in RHEL6), the other two are 3.11-only" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: constify dentry parameter in d_count() livelock avoidance in sget() allow O_TMPFILE to work with O_WRONLY
-rw-r--r--fs/open.c2
-rw-r--r--fs/super.c25
-rw-r--r--include/linux/dcache.h2
-rw-r--r--include/uapi/asm-generic/fcntl.h4
4 files changed, 15 insertions, 18 deletions
diff --git a/fs/open.c b/fs/open.c
index 9156cb050d08..d53e29895082 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -844,6 +844,8 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o
if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
return -EINVAL;
acc_mode = MAY_OPEN | ACC_MODE(flags);
+ if (!(acc_mode & MAY_WRITE))
+ return -EINVAL;
} else if (flags & O_PATH) {
/*
* If we have O_PATH in the open flag. Then we
diff --git a/fs/super.c b/fs/super.c
index 7465d4364208..68307c029228 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -336,19 +336,19 @@ EXPORT_SYMBOL(deactivate_super);
* and want to turn it into a full-blown active reference. grab_super()
* is called with sb_lock held and drops it. Returns 1 in case of
* success, 0 if we had failed (superblock contents was already dead or
- * dying when grab_super() had been called).
+ * dying when grab_super() had been called). Note that this is only
+ * called for superblocks not in rundown mode (== ones still on ->fs_supers
+ * of their type), so increment of ->s_count is OK here.
*/
static int grab_super(struct super_block *s) __releases(sb_lock)
{
- if (atomic_inc_not_zero(&s->s_active)) {
- spin_unlock(&sb_lock);
- return 1;
- }
- /* it's going away */
s->s_count++;
spin_unlock(&sb_lock);
- /* wait for it to die */
down_write(&s->s_umount);
+ if ((s->s_flags & MS_BORN) && atomic_inc_not_zero(&s->s_active)) {
+ put_super(s);
+ return 1;
+ }
up_write(&s->s_umount);
put_super(s);
return 0;
@@ -463,11 +463,6 @@ retry:
destroy_super(s);
s = NULL;
}
- down_write(&old->s_umount);
- if (unlikely(!(old->s_flags & MS_BORN))) {
- deactivate_locked_super(old);
- goto retry;
- }
return old;
}
}
@@ -660,10 +655,10 @@ restart:
if (hlist_unhashed(&sb->s_instances))
continue;
if (sb->s_bdev == bdev) {
- if (grab_super(sb)) /* drops sb_lock */
- return sb;
- else
+ if (!grab_super(sb))
goto restart;
+ up_write(&sb->s_umount);
+ return sb;
}
}
spin_unlock(&sb_lock);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 3092df3614ae..b90337c9d468 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -324,7 +324,7 @@ static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
return ret;
}
-static inline unsigned d_count(struct dentry *dentry)
+static inline unsigned d_count(const struct dentry *dentry)
{
return dentry->d_count;
}
diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-generic/fcntl.h
index 05ac354e124d..95e46c8e05f9 100644
--- a/include/uapi/asm-generic/fcntl.h
+++ b/include/uapi/asm-generic/fcntl.h
@@ -89,8 +89,8 @@
#endif
/* a horrid kludge trying to make sure that this will fail on old kernels */
-#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY | O_RDWR)
-#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT | O_ACCMODE)
+#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
+#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT)
#ifndef O_NDELAY
#define O_NDELAY O_NONBLOCK