fs/inode.c | 1
fs/namei.c | 66 ++++++++++++++++++++++++++++++++++++++---------------
include/linux/fs.h | 11 ++++----
3 files changed, 54 insertions(+), 24 deletions(-)
Index: linux-2.6.10/fs/namei.c
===================================================================
--- linux-2.6.10.orig/fs/namei.c 2005-01-28 19:32:13.000000000 +0300
+++ linux-2.6.10/fs/namei.c 2005-02-19 20:40:05.763437304 +0300
@@ -104,6 +104,28 @@
* any extra contention...
*/
+static inline struct semaphore * lock_sem(struct inode *dir, struct qstr *name)
+{
+ if (IS_PDIROPS(dir)) {
+ struct super_block *sb;
+ /* name->hash expected to be already calculated */
+ sb = dir->i_sb;
+ BUG_ON(sb->s_pdirops_sems == NULL);
+ return sb->s_pdirops_sems + name->hash % sb->s_pdirops_size;
+ }
+ return &dir->i_sem;
+}
+
+static inline void lock_dir(struct inode *dir, struct qstr *name)
+{
+ down(lock_sem(dir, name));
+}
+
+static inline void unlock_dir(struct inode *dir, struct qstr *name)
+{
+ up(lock_sem(dir, name));
+}
+
/* In order to reduce some races, while at the same time doing additional
* checking and hopefully speeding things up, we copy filenames to the
* kernel data space before using them..
@@ -380,7 +402,7 @@
struct dentry * result;
struct inode *dir = parent->d_inode;
- down(&dir->i_sem);
+ lock_dir(dir, name);
/*
* First re-do the cached lookup just in case it was created
* while we waited for the directory semaphore..
@@ -406,7 +428,7 @@
else
result = dentry;
}
- up(&dir->i_sem);
+ unlock_dir(dir, name);
return result;
}
@@ -414,7 +436,7 @@
* Uhhuh! Nasty case: the cache was re-populated while
* we waited on the semaphore. Need to revalidate.
*/
- up(&dir->i_sem);
+ unlock_dir(dir, name);
if (result->d_op && result->d_op->d_revalidate) {
if (!result->d_op->d_revalidate(result, nd) &&
!d_invalidate(result)) {
dput(result);
@@ -1182,12 +1204,26 @@
/*
* p1 and p2 should be directories on the same fs.
*/
-struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
+struct dentry *lock_rename(struct dentry *p1, struct qstr *n1,
+ struct dentry *p2, struct qstr *n2)
{
struct dentry *p;
if (p1 == p2) {
- down(&p1->d_inode->i_sem);
+ if (IS_PDIROPS(p1->d_inode)) {
+ unsigned int h1, h2;
+ h1 = n1->hash % p1->d_inode->i_sb->s_pdirops_size;
+ h2 = n2->hash % p2->d_inode->i_sb->s_pdirops_size;
+ if (h1 < h2) {
+ lock_dir(p1->d_inode, n1);
+ lock_dir(p2->d_inode, n2);
+ } else if (h1 > h2) {
+ lock_dir(p2->d_inode, n2);
+ lock_dir(p1->d_inode, n1);
+ } else
+ lock_dir(p1->d_inode, n1);
+ } else
+ down(&p1->d_inode->i_sem);
return NULL;
}
@@ -1195,31 +1231,35 @@
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);
+ lock_dir(p2->d_inode, n2);
+ lock_dir(p1->d_inode, n1);
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);
+ lock_dir(p1->d_inode, n1);
+ lock_dir(p2->d_inode, n2);
return p;
}
}
- down(&p1->d_inode->i_sem);
- down(&p2->d_inode->i_sem);
+ lock_dir(p1->d_inode, n1);
+ lock_dir(p2->d_inode, n2);
return NULL;
}
-void unlock_rename(struct dentry *p1, struct dentry *p2)
+void unlock_rename(struct dentry *p1, struct qstr *n1,
+ struct dentry *p2, struct qstr *n2)
{
- up(&p1->d_inode->i_sem);
+ unlock_dir(p1->d_inode, n1);
if (p1 != p2) {
- up(&p2->d_inode->i_sem);
+ unlock_dir(p2->d_inode, n2);
up(&p1->d_inode->i_sb->s_vfs_rename_sem);
+ } else if (IS_PDIROPS(p1->d_inode) &&
+ n1->hash != n2->hash) {
+ unlock_dir(p2->d_inode, n2);
}
}
@@ -1386,13 +1426,13 @@
dir = nd->dentry;
nd->flags &= ~LOOKUP_PARENT;
- down(&dir->d_inode->i_sem);
+ lock_dir(dir->d_inode, &nd->last);
dentry = __lookup_hash(&nd->last, nd->dentry, nd);
do_last:
error = PTR_ERR(dentry);
if (IS_ERR(dentry)) {
- up(&dir->d_inode->i_sem);
+ unlock_dir(dir->d_inode, &nd->last);
goto exit;
}
@@ -1401,7 +1441,7 @@
if (!IS_POSIXACL(dir->d_inode))
mode &= ~current->fs->umask;
error = vfs_create(dir->d_inode, dentry, mode, nd);
- up(&dir->d_inode->i_sem);
+ unlock_dir(dir->d_inode, &nd->last);
dput(nd->dentry);
nd->dentry = dentry;
if (error)
@@ -1415,7 +1455,7 @@
/*
* It already exists.
*/
- up(&dir->d_inode->i_sem);
+ unlock_dir(dir->d_inode, &nd->last);
error = -EEXIST;
if (flag & O_EXCL)
@@ -1499,7 +1539,7 @@
goto exit;
}
dir = nd->dentry;
- down(&dir->d_inode->i_sem);
+ lock_dir(dir->d_inode, &nd->last);
dentry = __lookup_hash(&nd->last, nd->dentry, nd);
putname(nd->last.name);
goto do_last;
@@ -1517,7 +1557,7 @@
{
struct dentry *dentry;
- down(&nd->dentry->d_inode->i_sem);
+ lock_dir(nd->dentry->d_inode, &nd->last);
dentry = ERR_PTR(-EEXIST);
if (nd->last_type != LAST_NORM)
goto fail;
@@ -1602,7 +1642,7 @@
}
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ unlock_dir(nd.dentry->d_inode, &nd.last);
path_release(&nd);
out:
putname(tmp);
@@ -1656,7 +1696,7 @@
error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ unlock_dir(nd.dentry->d_inode, &nd.last);
path_release(&nd);
out:
putname(tmp);
@@ -1757,14 +1797,14 @@
error = -EBUSY;
goto exit1;
}
- down(&nd.dentry->d_inode->i_sem);
+ lock_dir(nd.dentry->d_inode, &nd.last);
dentry = lookup_hash(&nd.last, nd.dentry);
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);
+ unlock_dir(nd.dentry->d_inode, &nd.last);
exit1:
path_release(&nd);
exit:
@@ -1826,7 +1866,7 @@
error = -EISDIR;
if (nd.last_type != LAST_NORM)
goto exit1;
- down(&nd.dentry->d_inode->i_sem);
+ lock_dir(nd.dentry->d_inode, &nd.last);
dentry = lookup_hash(&nd.last, nd.dentry);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
@@ -1840,7 +1880,7 @@
exit2:
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ unlock_dir(nd.dentry->d_inode, &nd.last);
if (inode)
iput(inode); /* truncate the inode here */
exit1:
@@ -1902,7 +1942,7 @@
error = vfs_symlink(nd.dentry->d_inode, dentry, from,
S_IALLUGO);
dput(dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ unlock_dir(nd.dentry->d_inode, &nd.last);
path_release(&nd);
out:
putname(to);
@@ -1986,7 +2026,7 @@
error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
dput(new_dentry);
}
- up(&nd.dentry->d_inode->i_sem);
+ unlock_dir(nd.dentry->d_inode, &nd.last);
out_release:
path_release(&nd);
out:
@@ -2174,7 +2214,7 @@
if (newnd.last_type != LAST_NORM)
goto exit2;
- trap = lock_rename(new_dir, old_dir);
+ trap = lock_rename(new_dir, &newnd.last, old_dir, &oldnd.last);
old_dentry = lookup_hash(&oldnd.last, old_dir);
error = PTR_ERR(old_dentry);
@@ -2212,7 +2252,7 @@
exit4:
dput(old_dentry);
exit3:
- unlock_rename(new_dir, old_dir);
+ unlock_rename(new_dir, &newnd.last, old_dir, &oldnd.last);
exit2:
path_release(&newnd);
exit1:
Index: linux-2.6.10/fs/super.c
===================================================================
--- linux-2.6.10.orig/fs/super.c 2005-01-28 19:32:13.000000000 +0300
+++ linux-2.6.10/fs/super.c 2005-02-19 18:11:50.000000000 +0300
@@ -172,6 +172,10 @@
down_write(&s->s_umount);
fs->kill_sb(s);
put_filesystem(fs);
+ if (s->s_flags & S_PDIROPS) {
+ BUG_ON(s->s_pdirops_sems == NULL);
+ kfree(s->s_pdirops_sems);
+ }
put_super(s);
}
}
@@ -791,6 +795,22 @@
EXPORT_SYMBOL(get_sb_single);
+static int init_pdirops_sems(struct super_block *sb)
+{
+ int i;
+
+ /* XXX: should be memsize dependent? -bzzz */
+ sb->s_pdirops_size = 1024;
+
+ sb->s_pdirops_sems = kmalloc(sizeof(struct semaphore) *
+ sb->s_pdirops_size, GFP_KERNEL);
+ if (sb->s_pdirops_sems == NULL)
+ return -ENOMEM;
+ for (i = 0; i < sb->s_pdirops_size; i++)
+ sema_init(&sb->s_pdirops_sems[i], 1);
+ return 0;
+}
+
struct vfsmount *
do_kern_mount(const char *fstype, int flags, const char *name, void *data)
{
@@ -827,6 +847,11 @@
error = security_sb_kern_mount(sb, secdata);
if (error)
goto out_sb;
+ if (sb->s_flags & S_PDIROPS) {
+ error = init_pdirops_sems(sb);
+ if (error)
+ goto out_sb;
+ }
mnt->mnt_sb = sb;
mnt->mnt_root = dget(sb->s_root);
mnt->mnt_mountpoint = sb->s_root;
Index: linux-2.6.10/include/linux/fs.h
===================================================================
--- linux-2.6.10.orig/include/linux/fs.h 2005-01-28 19:32:15.000000000
+0300
+++ linux-2.6.10/include/linux/fs.h 2005-02-19 18:11:50.000000000 +0300
@@ -150,6 +150,7 @@
#define S_DIRSYNC 64 /* Directory modifications are synchronous */
#define S_NOCMTIME 128 /* Do not update file c/mtime */
#define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */
+#define S_PDIROPS 512 /* Parallel directory operations */
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
@@ -180,6 +181,7 @@
#define IS_NODIRATIME(inode) __IS_FLG(inode, MS_NODIRATIME)
#define IS_POSIXACL(inode) __IS_FLG(inode, MS_POSIXACL)
#define IS_ONE_SECOND(inode) __IS_FLG(inode, MS_ONE_SECOND)
+#define IS_PDIROPS(inode) __IS_FLG(inode, S_PDIROPS)
#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD)
#define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME)
@@ -797,6 +799,8 @@
* even looking at it. You had been warned.
*/
struct semaphore s_vfs_rename_sem; /* Kludge */
+ struct semaphore *s_pdirops_sems;
+ int s_pdirops_size;
};
/*
Index: linux-2.6.10/include/linux/namei.h
===================================================================
--- linux-2.6.10.orig/include/linux/namei.h 2005-01-28 19:29:50.000000000
+0300
+++ linux-2.6.10/include/linux/namei.h 2005-02-19 19:59:19.291357592 +0300
@@ -69,8 +69,10 @@
extern int follow_down(struct vfsmount **, struct dentry **);
extern int follow_up(struct vfsmount **, struct dentry **);
-extern struct dentry *lock_rename(struct dentry *, struct dentry *);
-extern void unlock_rename(struct dentry *, struct dentry *);
+extern struct dentry *lock_rename(struct dentry *, struct qstr *,
+ struct dentry *, struct qstr *);
+extern void unlock_rename(struct dentry *, struct qstr *,
+ struct dentry *, struct qstr *);
static inline void nd_set_link(struct nameidata *nd, char *path)
{
-
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