X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fdcache.c;h=3ee588d5f585b54d7aa50358648521b64423b3f8;hb=38bbca6b6f164e08a4a9cdfd719fff679af98375;hp=44f6cf23b70e3baf4affccf31a68568aff7dd496;hpb=877c357e7511395bc923ec9efc2e8b021a17ed79;p=linux-2.6-omap-h63xx.git

diff --git a/fs/dcache.c b/fs/dcache.c
index 44f6cf23b70..3ee588d5f58 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -95,6 +95,14 @@ static void d_free(struct dentry *dentry)
 		call_rcu(&dentry->d_u.d_rcu, d_callback);
 }
 
+static void dentry_lru_remove(struct dentry *dentry)
+{
+	if (!list_empty(&dentry->d_lru)) {
+		list_del_init(&dentry->d_lru);
+		dentry_stat.nr_unused--;
+	}
+}
+
 /*
  * Release the dentry's inode, using the filesystem
  * d_iput() operation if defined.
@@ -211,13 +219,7 @@ repeat:
 unhash_it:
 	__d_drop(dentry);
 kill_it:
-	/* If dentry was on d_lru list
-	 * delete it from there
-	 */
-	if (!list_empty(&dentry->d_lru)) {
-		list_del(&dentry->d_lru);
-		dentry_stat.nr_unused--;
-	}
+	dentry_lru_remove(dentry);
 	dentry = d_kill(dentry);
 	if (dentry)
 		goto repeat;
@@ -285,10 +287,7 @@ int d_invalidate(struct dentry * dentry)
 static inline struct dentry * __dget_locked(struct dentry *dentry)
 {
 	atomic_inc(&dentry->d_count);
-	if (!list_empty(&dentry->d_lru)) {
-		dentry_stat.nr_unused--;
-		list_del_init(&dentry->d_lru);
-	}
+	dentry_lru_remove(dentry);
 	return dentry;
 }
 
@@ -404,10 +403,7 @@ static void prune_one_dentry(struct dentry * dentry)
 
 		if (dentry->d_op && dentry->d_op->d_delete)
 			dentry->d_op->d_delete(dentry);
-		if (!list_empty(&dentry->d_lru)) {
-			list_del(&dentry->d_lru);
-			dentry_stat.nr_unused--;
-		}
+		dentry_lru_remove(dentry);
 		__d_drop(dentry);
 		dentry = d_kill(dentry);
 		spin_lock(&dcache_lock);
@@ -596,10 +592,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 
 	/* detach this root from the system */
 	spin_lock(&dcache_lock);
-	if (!list_empty(&dentry->d_lru)) {
-		dentry_stat.nr_unused--;
-		list_del_init(&dentry->d_lru);
-	}
+	dentry_lru_remove(dentry);
 	__d_drop(dentry);
 	spin_unlock(&dcache_lock);
 
@@ -613,11 +606,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 			spin_lock(&dcache_lock);
 			list_for_each_entry(loop, &dentry->d_subdirs,
 					    d_u.d_child) {
-				if (!list_empty(&loop->d_lru)) {
-					dentry_stat.nr_unused--;
-					list_del_init(&loop->d_lru);
-				}
-
+				dentry_lru_remove(loop);
 				__d_drop(loop);
 				cond_resched_lock(&dcache_lock);
 			}
@@ -799,10 +788,7 @@ resume:
 		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
 		next = tmp->next;
 
-		if (!list_empty(&dentry->d_lru)) {
-			dentry_stat.nr_unused--;
-			list_del_init(&dentry->d_lru);
-		}
+		dentry_lru_remove(dentry);
 		/* 
 		 * move only zero ref count dentries to the end 
 		 * of the unused list for prune_dcache
@@ -1760,12 +1746,21 @@ shouldnt_be_hashed:
 	goto shouldnt_be_hashed;
 }
 
+static int prepend(char **buffer, int *buflen, const char *str,
+			  int namelen)
+{
+	*buflen -= namelen;
+	if (*buflen < 0)
+		return -ENAMETOOLONG;
+	*buffer -= namelen;
+	memcpy(*buffer, str, namelen);
+	return 0;
+}
+
 /**
  * d_path - return the path of a dentry
- * @dentry: dentry to report
- * @vfsmnt: vfsmnt to which the dentry belongs
- * @root: root dentry
- * @rootmnt: vfsmnt to which the root dentry belongs
+ * @path: the dentry/vfsmount to report
+ * @root: root vfsmnt/dentry (may be modified by this function)
  * @buffer: buffer to return value in
  * @buflen: buffer length
  *
@@ -1775,24 +1770,22 @@ shouldnt_be_hashed:
  * Returns the buffer or an error code if the path was too long.
  *
  * "buflen" should be positive. Caller holds the dcache_lock.
+ *
+ * If path is not reachable from the supplied root, then the value of
+ * root is changed (without modifying refcounts).
  */
-static char * __d_path( struct dentry *dentry, struct vfsmount *vfsmnt,
-			struct dentry *root, struct vfsmount *rootmnt,
-			char *buffer, int buflen)
+char *__d_path(const struct path *path, struct path *root,
+	       char *buffer, int buflen)
 {
+	struct dentry *dentry = path->dentry;
+	struct vfsmount *vfsmnt = path->mnt;
 	char * end = buffer+buflen;
 	char * retval;
-	int namelen;
-
-	*--end = '\0';
-	buflen--;
-	if (!IS_ROOT(dentry) && d_unhashed(dentry)) {
-		buflen -= 10;
-		end -= 10;
-		if (buflen < 0)
+
+	prepend(&end, &buflen, "\0", 1);
+	if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
+		(prepend(&end, &buflen, " (deleted)", 10) != 0))
 			goto Elong;
-		memcpy(end, " (deleted)", 10);
-	}
 
 	if (buflen < 1)
 		goto Elong;
@@ -1803,7 +1796,7 @@ static char * __d_path( struct dentry *dentry, struct vfsmount *vfsmnt,
 	for (;;) {
 		struct dentry * parent;
 
-		if (dentry == root && vfsmnt == rootmnt)
+		if (dentry == root->dentry && vfsmnt == root->mnt)
 			break;
 		if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
 			/* Global root? */
@@ -1819,13 +1812,10 @@ static char * __d_path( struct dentry *dentry, struct vfsmount *vfsmnt,
 		}
 		parent = dentry->d_parent;
 		prefetch(parent);
-		namelen = dentry->d_name.len;
-		buflen -= namelen + 1;
-		if (buflen < 0)
+		if ((prepend(&end, &buflen, dentry->d_name.name,
+				dentry->d_name.len) != 0) ||
+		    (prepend(&end, &buflen, "/", 1) != 0))
 			goto Elong;
-		end -= namelen;
-		memcpy(end, dentry->d_name.name, namelen);
-		*--end = '/';
 		retval = end;
 		dentry = parent;
 	}
@@ -1833,24 +1823,35 @@ static char * __d_path( struct dentry *dentry, struct vfsmount *vfsmnt,
 	return retval;
 
 global_root:
-	namelen = dentry->d_name.len;
-	buflen -= namelen;
-	if (buflen < 0)
+	retval += 1;	/* hit the slash */
+	if (prepend(&retval, &buflen, dentry->d_name.name,
+		    dentry->d_name.len) != 0)
 		goto Elong;
-	retval -= namelen-1;	/* hit the slash */
-	memcpy(retval, dentry->d_name.name, namelen);
+	root->mnt = vfsmnt;
+	root->dentry = dentry;
 	return retval;
 Elong:
 	return ERR_PTR(-ENAMETOOLONG);
 }
 
-/* write full pathname into buffer and return start of pathname */
-char * d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
-				char *buf, int buflen)
+/**
+ * d_path - return the path of a dentry
+ * @path: path to report
+ * @buf: buffer to return value in
+ * @buflen: buffer length
+ *
+ * Convert a dentry into an ASCII path name. If the entry has been deleted
+ * the string " (deleted)" is appended. Note that this is ambiguous.
+ *
+ * Returns the buffer or an error code if the path was too long.
+ *
+ * "buflen" should be positive. Caller holds the dcache_lock.
+ */
+char *d_path(struct path *path, char *buf, int buflen)
 {
 	char *res;
-	struct vfsmount *rootmnt;
-	struct dentry *root;
+	struct path root;
+	struct path tmp;
 
 	/*
 	 * We have various synthetic filesystems that never get mounted.  On
@@ -1859,18 +1860,18 @@ char * d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
 	 * user wants to identify the object in /proc/pid/fd/.  The little hack
 	 * below allows us to generate a name for these objects on demand:
 	 */
-	if (dentry->d_op && dentry->d_op->d_dname)
-		return dentry->d_op->d_dname(dentry, buf, buflen);
+	if (path->dentry->d_op && path->dentry->d_op->d_dname)
+		return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
 
 	read_lock(&current->fs->lock);
-	rootmnt = mntget(current->fs->rootmnt);
-	root = dget(current->fs->root);
+	root = current->fs->root;
+	path_get(&root);
 	read_unlock(&current->fs->lock);
 	spin_lock(&dcache_lock);
-	res = __d_path(dentry, vfsmnt, root, rootmnt, buf, buflen);
+	tmp = root;
+	res = __d_path(path, &tmp, buf, buflen);
 	spin_unlock(&dcache_lock);
-	dput(root);
-	mntput(rootmnt);
+	path_put(&root);
 	return res;
 }
 
@@ -1895,6 +1896,48 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen,
 	return memcpy(buffer, temp, sz);
 }
 
+/*
+ * Write full pathname from the root of the filesystem into the buffer.
+ */
+char *dentry_path(struct dentry *dentry, char *buf, int buflen)
+{
+	char *end = buf + buflen;
+	char *retval;
+
+	spin_lock(&dcache_lock);
+	prepend(&end, &buflen, "\0", 1);
+	if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
+		(prepend(&end, &buflen, "//deleted", 9) != 0))
+			goto Elong;
+	if (buflen < 1)
+		goto Elong;
+	/* Get '/' right */
+	retval = end-1;
+	*retval = '/';
+
+	for (;;) {
+		struct dentry *parent;
+		if (IS_ROOT(dentry))
+			break;
+
+		parent = dentry->d_parent;
+		prefetch(parent);
+
+		if ((prepend(&end, &buflen, dentry->d_name.name,
+				dentry->d_name.len) != 0) ||
+		    (prepend(&end, &buflen, "/", 1) != 0))
+			goto Elong;
+
+		retval = end;
+		dentry = parent;
+	}
+	spin_unlock(&dcache_lock);
+	return retval;
+Elong:
+	spin_unlock(&dcache_lock);
+	return ERR_PTR(-ENAMETOOLONG);
+}
+
 /*
  * NOTE! The user-level library version returns a
  * character pointer. The kernel system call just
@@ -1916,28 +1959,28 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen,
 asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
 {
 	int error;
-	struct vfsmount *pwdmnt, *rootmnt;
-	struct dentry *pwd, *root;
+	struct path pwd, root;
 	char *page = (char *) __get_free_page(GFP_USER);
 
 	if (!page)
 		return -ENOMEM;
 
 	read_lock(&current->fs->lock);
-	pwdmnt = mntget(current->fs->pwdmnt);
-	pwd = dget(current->fs->pwd);
-	rootmnt = mntget(current->fs->rootmnt);
-	root = dget(current->fs->root);
+	pwd = current->fs->pwd;
+	path_get(&pwd);
+	root = current->fs->root;
+	path_get(&root);
 	read_unlock(&current->fs->lock);
 
 	error = -ENOENT;
 	/* Has the current directory has been unlinked? */
 	spin_lock(&dcache_lock);
-	if (pwd->d_parent == pwd || !d_unhashed(pwd)) {
+	if (pwd.dentry->d_parent == pwd.dentry || !d_unhashed(pwd.dentry)) {
 		unsigned long len;
+		struct path tmp = root;
 		char * cwd;
 
-		cwd = __d_path(pwd, pwdmnt, root, rootmnt, page, PAGE_SIZE);
+		cwd = __d_path(&pwd, &tmp, page, PAGE_SIZE);
 		spin_unlock(&dcache_lock);
 
 		error = PTR_ERR(cwd);
@@ -1955,10 +1998,8 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
 		spin_unlock(&dcache_lock);
 
 out:
-	dput(pwd);
-	mntput(pwdmnt);
-	dput(root);
-	mntput(rootmnt);
+	path_put(&pwd);
+	path_put(&root);
 	free_page((unsigned long) page);
 	return error;
 }