reiserfs: fixup xattr_root caching

The xattr_root caching was broken from my previous patch set. It wouldn't cause corruption, but could cause decreased performance due to allocating a larger chunk of the journal (~ 27 blocks) than it would actually use. This patch loads the xattr root dentry at xattr initialization and creates it on-demand. Since we're using the cached dentry, there's no point in keeping lookup_or_create_dir around, so that's removed. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

reiserfs: fixup xattr_root caching
The xattr_root caching was broken from my previous patch set. It wouldn't cause corruption, but could cause decreased performance due to allocating a larger chunk of the journal (~ 27 blocks) than it would actually use. This patch loads the xattr root dentry at xattr initialization and creates it on-demand. Since we're using the cached dentry, there's no point in keeping lookup_or_create_dir around, so that's removed. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Jeff Mahoney · Al Viro
1 parent edcc37a047
Showing 3 changed files with 48 additions and 29 deletions Side-by-side Diff
fs/reiserfs/xattr.c
include/linux/reiserfs_fs_sb.h
include/linux/reiserfs_xattr.h
@@ -113,36 +113,28 @@
  
 #define xattr_may_create(flags)	(!flags || flags & XATTR_CREATE)
  
-/* Returns and possibly creates the xattr dir. */
-static struct dentry *lookup_or_create_dir(struct dentry *parent,
-					    const char *name, int flags)
+static struct dentry *open_xa_root(struct super_block *sb, int flags)
 {
-	struct dentry *dentry;
-	BUG_ON(!parent);
+	struct dentry *privroot = REISERFS_SB(sb)->priv_root;
+	struct dentry *xaroot;
+	if (!privroot->d_inode)
+		return ERR_PTR(-ENODATA);
  
-	mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_XATTR);
-	dentry = lookup_one_len(name, parent, strlen(name));
-	if (!IS_ERR(dentry) && !dentry->d_inode) {
-		int err = -ENODATA;
+	mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
  
+	xaroot = dget(REISERFS_SB(sb)->xattr_root);
+	if (!xaroot->d_inode) {
+		int err = -ENODATA;
 		if (xattr_may_create(flags))
-			err = xattr_mkdir(parent->d_inode, dentry, 0700);
-
+			err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
 		if (err) {
-			dput(dentry);
-			dentry = ERR_PTR(err);
+			dput(xaroot);
+			xaroot = ERR_PTR(err);
 		}
 	}
-	mutex_unlock(&parent->d_inode->i_mutex);
-	return dentry;
-}
  
-static struct dentry *open_xa_root(struct super_block *sb, int flags)
-{
-	struct dentry *privroot = REISERFS_SB(sb)->priv_root;
-	if (!privroot)
-		return ERR_PTR(-ENODATA);
-	return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
+	mutex_unlock(&privroot->d_inode->i_mutex);
+	return xaroot;
 }
  
 static struct dentry *open_xa_dir(const struct inode *inode, int flags)
  
@@ -158,10 +150,22 @@
 		 le32_to_cpu(INODE_PKEY(inode)->k_objectid),
 		 inode->i_generation);
  
-	xadir = lookup_or_create_dir(xaroot, namebuf, flags);
+	mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
+
+	xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
+	if (!IS_ERR(xadir) && !xadir->d_inode) {
+		int err = -ENODATA;
+		if (xattr_may_create(flags))
+			err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
+		if (err) {
+			dput(xadir);
+			xadir = ERR_PTR(err);
+		}
+	}
+
+	mutex_unlock(&xaroot->d_inode->i_mutex);
 	dput(xaroot);
 	return xadir;
-
 }
  
 /* The following are side effects of other operations that aren't explicitly
  
  
  
@@ -986,19 +990,33 @@
 int reiserfs_xattr_init(struct super_block *s, int mount_flags)
 {
 	int err = 0;
+	struct dentry *privroot = REISERFS_SB(s)->priv_root;
  
 #ifdef CONFIG_REISERFS_FS_XATTR
 	err = xattr_mount_check(s);
 	if (err)
 		goto error;
  
-	if (!REISERFS_SB(s)->priv_root->d_inode && !(mount_flags & MS_RDONLY)) {
+	if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
 		mutex_lock(&s->s_root->d_inode->i_mutex);
 		err = create_privroot(REISERFS_SB(s)->priv_root);
 		mutex_unlock(&s->s_root->d_inode->i_mutex);
 	}
-	if (!err)
+
+	if (privroot->d_inode) {
 		s->s_xattr = reiserfs_xattr_handlers;
+		mutex_lock(&privroot->d_inode->i_mutex);
+		if (!REISERFS_SB(s)->xattr_root) {
+			struct dentry *dentry;
+			dentry = lookup_one_len(XAROOT_NAME, privroot,
+						strlen(XAROOT_NAME));
+			if (!IS_ERR(dentry))
+				REISERFS_SB(s)->xattr_root = dentry;
+			else
+				err = PTR_ERR(dentry);
+		}
+		mutex_unlock(&privroot->d_inode->i_mutex);
+	}
  
 error:
 	if (err) {
  
  
@@ -1008,11 +1026,12 @@
 #endif
  
 	/* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
-	s->s_flags = s->s_flags & ~MS_POSIXACL;
 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
 	if (reiserfs_posixacl(s))
 		s->s_flags |= MS_POSIXACL;
+	else
 #endif
+		s->s_flags &= ~MS_POSIXACL;
  
 	return err;
 }
@@ -402,7 +402,7 @@
 	int reserved_blocks;	/* amount of blocks reserved for further allocations */
 	spinlock_t bitmap_lock;	/* this lock on now only used to protect reserved_blocks variable */
 	struct dentry *priv_root;	/* root of /.reiserfs_priv */
-	struct dentry *xattr_root;	/* root of /.reiserfs_priv/.xa */
+	struct dentry *xattr_root;	/* root of /.reiserfs_priv/xattrs */
 	int j_errno;
 #ifdef CONFIG_QUOTA
 	char *s_qf_names[MAXQUOTAS];
@@ -98,7 +98,7 @@
  
 	if ((REISERFS_I(inode)->i_flags & i_has_xattr_dir) == 0) {
 		nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
-		if (REISERFS_SB(inode->i_sb)->xattr_root == NULL)
+		if (!REISERFS_SB(inode->i_sb)->xattr_root->d_inode)
 			nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
 	}
...	...	@@ -113,36 +113,28 @@
113	113
114	114	#define xattr_may_create(flags) (!flags \|\| flags & XATTR_CREATE)
115	115
116		-/* Returns and possibly creates the xattr dir. */
117		-static struct dentry lookup_or_create_dir(struct dentry parent,
118		- const char *name, int flags)
	116	+static struct dentry open_xa_root(struct super_block sb, int flags)
119	117	{
120		- struct dentry *dentry;
121		- BUG_ON(!parent);
	118	+ struct dentry *privroot = REISERFS_SB(sb)->priv_root;
	119	+ struct dentry *xaroot;
	120	+ if (!privroot->d_inode)
	121	+ return ERR_PTR(-ENODATA);
122	122
123		- mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_XATTR);
124		- dentry = lookup_one_len(name, parent, strlen(name));
125		- if (!IS_ERR(dentry) && !dentry->d_inode) {
126		- int err = -ENODATA;
	123	+ mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
127	124
	125	+ xaroot = dget(REISERFS_SB(sb)->xattr_root);
	126	+ if (!xaroot->d_inode) {
	127	+ int err = -ENODATA;
128	128	if (xattr_may_create(flags))
129		- err = xattr_mkdir(parent->d_inode, dentry, 0700);
130		-
	129	+ err = xattr_mkdir(privroot->d_inode, xaroot, 0700);
131	130	if (err) {
132		- dput(dentry);
133		- dentry = ERR_PTR(err);
	131	+ dput(xaroot);
	132	+ xaroot = ERR_PTR(err);
134	133	}
135	134	}
136		- mutex_unlock(&parent->d_inode->i_mutex);
137		- return dentry;
138		-}
139	135
140		-static struct dentry open_xa_root(struct super_block sb, int flags)
141		-{
142		- struct dentry *privroot = REISERFS_SB(sb)->priv_root;
143		- if (!privroot)
144		- return ERR_PTR(-ENODATA);
145		- return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
	136	+ mutex_unlock(&privroot->d_inode->i_mutex);
	137	+ return xaroot;
146	138	}
147	139
148	140	static struct dentry open_xa_dir(const struct inode inode, int flags)
149	141
...	...	@@ -158,10 +150,22 @@
158	150	le32_to_cpu(INODE_PKEY(inode)->k_objectid),
159	151	inode->i_generation);
160	152
161		- xadir = lookup_or_create_dir(xaroot, namebuf, flags);
	153	+ mutex_lock_nested(&xaroot->d_inode->i_mutex, I_MUTEX_XATTR);
	154	+
	155	+ xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
	156	+ if (!IS_ERR(xadir) && !xadir->d_inode) {
	157	+ int err = -ENODATA;
	158	+ if (xattr_may_create(flags))
	159	+ err = xattr_mkdir(xaroot->d_inode, xadir, 0700);
	160	+ if (err) {
	161	+ dput(xadir);
	162	+ xadir = ERR_PTR(err);
	163	+ }
	164	+ }
	165	+
	166	+ mutex_unlock(&xaroot->d_inode->i_mutex);
162	167	dput(xaroot);
163	168	return xadir;
164		-
165	169	}
166	170
167	171	/* The following are side effects of other operations that aren't explicitly
168	172
169	173
170	174
...	...	@@ -986,19 +990,33 @@
986	990	int reiserfs_xattr_init(struct super_block *s, int mount_flags)
987	991	{
988	992	int err = 0;
	993	+ struct dentry *privroot = REISERFS_SB(s)->priv_root;
989	994
990	995	#ifdef CONFIG_REISERFS_FS_XATTR
991	996	err = xattr_mount_check(s);
992	997	if (err)
993	998	goto error;
994	999
995		- if (!REISERFS_SB(s)->priv_root->d_inode && !(mount_flags & MS_RDONLY)) {
	1000	+ if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
996	1001	mutex_lock(&s->s_root->d_inode->i_mutex);
997	1002	err = create_privroot(REISERFS_SB(s)->priv_root);
998	1003	mutex_unlock(&s->s_root->d_inode->i_mutex);
999	1004	}
1000		- if (!err)
	1005	+
	1006	+ if (privroot->d_inode) {
1001	1007	s->s_xattr = reiserfs_xattr_handlers;
	1008	+ mutex_lock(&privroot->d_inode->i_mutex);
	1009	+ if (!REISERFS_SB(s)->xattr_root) {
	1010	+ struct dentry *dentry;
	1011	+ dentry = lookup_one_len(XAROOT_NAME, privroot,
	1012	+ strlen(XAROOT_NAME));
	1013	+ if (!IS_ERR(dentry))
	1014	+ REISERFS_SB(s)->xattr_root = dentry;
	1015	+ else
	1016	+ err = PTR_ERR(dentry);
	1017	+ }
	1018	+ mutex_unlock(&privroot->d_inode->i_mutex);
	1019	+ }
1002	1020
1003	1021	error:
1004	1022	if (err) {
1005	1023
1006	1024
...	...	@@ -1008,11 +1026,12 @@
1008	1026	#endif
1009	1027
1010	1028	/* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1011		- s->s_flags = s->s_flags & ~MS_POSIXACL;
1012	1029	#ifdef CONFIG_REISERFS_FS_POSIX_ACL
1013	1030	if (reiserfs_posixacl(s))
1014	1031	s->s_flags \|= MS_POSIXACL;
	1032	+ else
1015	1033	#endif
	1034	+ s->s_flags &= ~MS_POSIXACL;
1016	1035
1017	1036	return err;
1018	1037	}
...	...	@@ -402,7 +402,7 @@
402	402	int reserved_blocks; /* amount of blocks reserved for further allocations */
403	403	spinlock_t bitmap_lock; /* this lock on now only used to protect reserved_blocks variable */
404	404	struct dentry priv_root; / root of /.reiserfs_priv */
405		- struct dentry xattr_root; / root of /.reiserfs_priv/.xa */
	405	+ struct dentry xattr_root; / root of /.reiserfs_priv/xattrs */
406	406	int j_errno;
407	407	#ifdef CONFIG_QUOTA
408	408	char *s_qf_names[MAXQUOTAS];
...	...	@@ -98,7 +98,7 @@
98	98
99	99	if ((REISERFS_I(inode)->i_flags & i_has_xattr_dir) == 0) {
100	100	nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
101		- if (REISERFS_SB(inode->i_sb)->xattr_root == NULL)
	101	+ if (!REISERFS_SB(inode->i_sb)->xattr_root->d_inode)
102	102	nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
103	103	}
104	104