[PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.
Modified-by: Ingo Molnar <mingo@elte.hu>
(finished the conversion)
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/fs/namei.c b/fs/namei.c
index 300eae0..0a8f073 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -438,7 +438,7 @@
struct dentry * result;
struct inode *dir = parent->d_inode;
- down(&dir->i_sem);
+ mutex_lock(&dir->i_mutex);
/*
* First re-do the cached lookup just in case it was created
* while we waited for the directory semaphore..
@@ -464,7 +464,7 @@
else
result = dentry;
}
- up(&dir->i_sem);
+ mutex_unlock(&dir->i_mutex);
return result;
}
@@ -472,7 +472,7 @@
* Uhhuh! Nasty case: the cache was re-populated while
* we waited on the semaphore. Need to revalidate.
*/
- up(&dir->i_sem);
+ mutex_unlock(&dir->i_mutex);
if (result->d_op && result->d_op->d_revalidate) {
if (!result->d_op->d_revalidate(result, nd) && !d_invalidate(result)) {
dput(result);
@@ -1366,7 +1366,7 @@
struct dentry *p;
if (p1 == p2) {
- down(&p1->d_inode->i_sem);
+ mutex_lock(&p1->d_inode->i_mutex);
return NULL;
}
@@ -1374,30 +1374,30 @@
for (p = p1; p->d_parent != p; p = p->d_parent) {
if (p->d_parent == p2) {
- down(&p2->d_inode->i_sem);
- down(&p1->d_inode->i_sem);
+ mutex_lock(&p2->d_inode->i_mutex);
+ mutex_lock(&p1->d_inode->i_mutex);
return p;
}
}
for (p = p2; p->d_parent != p; p = p->d_parent) {
if (p->d_parent == p1) {
- down(&p1->d_inode->i_sem);
- down(&p2->d_inode->i_sem);
+ mutex_lock(&p1->d_inode->i_mutex);
+ mutex_lock(&p2->d_inode->i_mutex);
return p;
}
}
- down(&p1->d_inode->i_sem);
- down(&p2->d_inode->i_sem);
+ mutex_lock(&p1->d_inode->i_mutex);
+ mutex_lock(&p2->d_inode->i_mutex);
return NULL;
}
void unlock_rename(struct dentry *p1, struct dentry *p2)
{
- up(&p1->d_inode->i_sem);
+ mutex_unlock(&p1->d_inode->i_mutex);
if (p1 != p2) {
- up(&p2->d_inode->i_sem);
+ mutex_unlock(&p2->d_inode->i_mutex);
up(&p1->d_inode->i_sb->s_vfs_rename_sem);
}
}
@@ -1563,14 +1563,14 @@
dir = nd->dentry;
nd->flags &= ~LOOKUP_PARENT;
- down(&dir->d_inode->i_sem);
+ mutex_lock(&dir->d_inode->i_mutex);
path.dentry = lookup_hash(nd);
path.mnt = nd->mnt;
do_last:
error = PTR_ERR(path.dentry);
if (IS_ERR(path.dentry)) {
- up(&dir->d_inode->i_sem);
+ mutex_unlock(&dir->d_inode->i_mutex);
goto exit;
}
@@ -1579,7 +1579,7 @@
if (!IS_POSIXACL(dir->d_inode))
mode &= ~current->fs->umask;
error = vfs_create(dir->d_inode, path.dentry, mode, nd);
- up(&dir->d_inode->i_sem);
+ mutex_unlock(&dir->d_inode->i_mutex);
dput(nd->dentry);
nd->dentry = path.dentry;
if (error)
@@ -1593,7 +1593,7 @@
/*
* It already exists.
*/
- up(&dir->d_inode->i_sem);
+ mutex_unlock(&dir->d_inode->i_mutex);
error = -EEXIST;
if (flag & O_EXCL)
@@ -1665,7 +1665,7 @@
goto exit;
}
dir = nd->dentry;
- down(&dir->d_inode->i_sem);
+ mutex_lock(&dir->d_inode->i_mutex);
path.dentry = lookup_hash(nd);
path.mnt = nd->mnt;
__putname(nd->last.name);
@@ -1680,13 +1680,13 @@
* Simple function to lookup and return a dentry and create it
* if it doesn't exist. Is SMP-safe.
*
- * Returns with nd->dentry->d_inode->i_sem locked.
+ * Returns with nd->dentry->d_inode->i_mutex locked.
*/
struct dentry *lookup_create(struct nameidata *nd, int is_dir)
{
struct dentry *dentry = ERR_PTR(-EEXIST);
- down(&nd->dentry->d_inode->i_sem);
+ mutex_lock(&nd->dentry->d_inode->i_mutex);
/*
* Yucky last component or no last component at all?
* (foo/., foo/.., /////)
@@ -1784,7 +1784,7 @@
}
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
path_release(&nd);
out:
putname(tmp);
@@ -1836,7 +1836,7 @@
error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
path_release(&nd);
out:
putname(tmp);
@@ -1885,7 +1885,7 @@
DQUOT_INIT(dir);
- down(&dentry->d_inode->i_sem);
+ mutex_lock(&dentry->d_inode->i_mutex);
dentry_unhash(dentry);
if (d_mountpoint(dentry))
error = -EBUSY;
@@ -1897,7 +1897,7 @@
dentry->d_inode->i_flags |= S_DEAD;
}
}
- up(&dentry->d_inode->i_sem);
+ mutex_unlock(&dentry->d_inode->i_mutex);
if (!error) {
d_delete(dentry);
}
@@ -1932,14 +1932,14 @@
error = -EBUSY;
goto exit1;
}
- down(&nd.dentry->d_inode->i_sem);
+ mutex_lock(&nd.dentry->d_inode->i_mutex);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
error = vfs_rmdir(nd.dentry->d_inode, dentry);
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
exit1:
path_release(&nd);
exit:
@@ -1959,7 +1959,7 @@
DQUOT_INIT(dir);
- down(&dentry->d_inode->i_sem);
+ mutex_lock(&dentry->d_inode->i_mutex);
if (d_mountpoint(dentry))
error = -EBUSY;
else {
@@ -1967,7 +1967,7 @@
if (!error)
error = dir->i_op->unlink(dir, dentry);
}
- up(&dentry->d_inode->i_sem);
+ mutex_unlock(&dentry->d_inode->i_mutex);
/* We don't d_delete() NFS sillyrenamed files--they still exist. */
if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
@@ -1979,7 +1979,7 @@
/*
* Make sure that the actual truncation of the file will occur outside its
- * directory's i_sem. Truncate can take a long time if there is a lot of
+ * directory's i_mutex. Truncate can take a long time if there is a lot of
* writeout happening, and we don't want to prevent access to the directory
* while waiting on the I/O.
*/
@@ -2001,7 +2001,7 @@
error = -EISDIR;
if (nd.last_type != LAST_NORM)
goto exit1;
- down(&nd.dentry->d_inode->i_sem);
+ mutex_lock(&nd.dentry->d_inode->i_mutex);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
@@ -2015,7 +2015,7 @@
exit2:
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
if (inode)
iput(inode); /* truncate the inode here */
exit1:
@@ -2075,7 +2075,7 @@
error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
path_release(&nd);
out:
putname(to);
@@ -2113,10 +2113,10 @@
if (error)
return error;
- down(&old_dentry->d_inode->i_sem);
+ mutex_lock(&old_dentry->d_inode->i_mutex);
DQUOT_INIT(dir);
error = dir->i_op->link(old_dentry, dir, new_dentry);
- up(&old_dentry->d_inode->i_sem);
+ mutex_unlock(&old_dentry->d_inode->i_mutex);
if (!error)
fsnotify_create(dir, new_dentry->d_name.name);
return error;
@@ -2157,7 +2157,7 @@
error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
dput(new_dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
out_release:
path_release(&nd);
out:
@@ -2178,7 +2178,7 @@
* sb->s_vfs_rename_sem. We might be more accurate, but that's another
* story.
* c) we have to lock _three_ objects - parents and victim (if it exists).
- * And that - after we got ->i_sem on parents (until then we don't know
+ * And that - after we got ->i_mutex on parents (until then we don't know
* whether the target exists). Solution: try to be smart with locking
* order for inodes. We rely on the fact that tree topology may change
* only under ->s_vfs_rename_sem _and_ that parent of the object we
@@ -2195,9 +2195,9 @@
* stuff into VFS), but the former is not going away. Solution: the same
* trick as in rmdir().
* e) conversion from fhandle to dentry may come in the wrong moment - when
- * we are removing the target. Solution: we will have to grab ->i_sem
+ * we are removing the target. Solution: we will have to grab ->i_mutex
* in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on
- * ->i_sem on parents, which works but leads to some truely excessive
+ * ->i_mutex on parents, which works but leads to some truely excessive
* locking].
*/
static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
@@ -2222,7 +2222,7 @@
target = new_dentry->d_inode;
if (target) {
- down(&target->i_sem);
+ mutex_lock(&target->i_mutex);
dentry_unhash(new_dentry);
}
if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
@@ -2232,7 +2232,7 @@
if (target) {
if (!error)
target->i_flags |= S_DEAD;
- up(&target->i_sem);
+ mutex_unlock(&target->i_mutex);
if (d_unhashed(new_dentry))
d_rehash(new_dentry);
dput(new_dentry);
@@ -2255,7 +2255,7 @@
dget(new_dentry);
target = new_dentry->d_inode;
if (target)
- down(&target->i_sem);
+ mutex_lock(&target->i_mutex);
if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
error = -EBUSY;
else
@@ -2266,7 +2266,7 @@
d_move(old_dentry, new_dentry);
}
if (target)
- up(&target->i_sem);
+ mutex_unlock(&target->i_mutex);
dput(new_dentry);
return error;
}