[PATCH] splice: page stealing needs to wait_on_page_writeback()

[linux-2.6-omap-h63xx.git] / fs / sysfs / dir.c

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 37d7a6875d86908556726b070782b13ba87eb5ae..f26880a4785eec127e80ce736144624c3016098c 100644 (file)
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -8,6 +8,7 @@
 #include <linux/mount.h>
 #include <linux/module.h>
 #include <linux/kobject.h>
+#include <linux/namei.h>
 #include "sysfs.h"
 
 DECLARE_RWSEM(sysfs_rename_sem);
@@ -49,6 +50,32 @@ static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
        return sd;
 }
 
+/**
+ *
+ * Return -EEXIST if there is already a sysfs element with the same name for
+ * the same parent.
+ *
+ * called with parent inode's i_mutex held
+ */
+int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
+                         const unsigned char *new)
+{
+       struct sysfs_dirent * sd;
+
+       list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+               if (sd->s_element) {
+                       const unsigned char *existing = sysfs_get_name(sd);
+                       if (strcmp(existing, new))
+                               continue;
+                       else
+                               return -EEXIST;
+               }
+       }
+
+       return 0;
+}
+
+
 int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
                        void * element, umode_t mode, int type)
 {
@@ -98,10 +125,14 @@ static int create_dir(struct kobject * k, struct dentry * p,
        int error;
        umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
 
-       down(&p->d_inode->i_sem);
-       *d = sysfs_get_dentry(p,n);
+       mutex_lock(&p->d_inode->i_mutex);
+       *d = lookup_one_len(n, p, strlen(n));
        if (!IS_ERR(*d)) {
-               error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
+               if (sysfs_dirent_exist(p->d_fsdata, n))
+                       error = -EEXIST;
+               else
+                       error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
+                                                               SYSFS_DIR);
                if (!error) {
                        error = sysfs_create(*d, mode, init_dir);
                        if (!error) {
@@ -111,13 +142,17 @@ static int create_dir(struct kobject * k, struct dentry * p,
                        }
                }
                if (error && (error != -EEXIST)) {
-                       sysfs_put((*d)->d_fsdata);
+                       struct sysfs_dirent *sd = (*d)->d_fsdata;
+                       if (sd) {
+                               list_del_init(&sd->s_sibling);
+                               sysfs_put(sd);
+                       }
                        d_drop(*d);
                }
                dput(*d);
        } else
                error = PTR_ERR(*d);
-       up(&p->d_inode->i_sem);
+       mutex_unlock(&p->d_inode->i_mutex);
        return error;
 }
 
@@ -241,7 +276,7 @@ static void remove_dir(struct dentry * d)
        struct dentry * parent = dget(d->d_parent);
        struct sysfs_dirent * sd;
 
-       down(&parent->d_inode->i_sem);
+       mutex_lock(&parent->d_inode->i_mutex);
        d_delete(d);
        sd = d->d_fsdata;
        list_del_init(&sd->s_sibling);
@@ -252,7 +287,7 @@ static void remove_dir(struct dentry * d)
        pr_debug(" o %s removing done (%d)\n",d->d_name.name,
                 atomic_read(&d->d_count));
 
-       up(&parent->d_inode->i_sem);
+       mutex_unlock(&parent->d_inode->i_mutex);
        dput(parent);
 }
 
@@ -281,7 +316,7 @@ void sysfs_remove_dir(struct kobject * kobj)
                return;
 
        pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
-       down(&dentry->d_inode->i_sem);
+       mutex_lock(&dentry->d_inode->i_mutex);
        parent_sd = dentry->d_fsdata;
        list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
                if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED))
@@ -290,13 +325,14 @@ void sysfs_remove_dir(struct kobject * kobj)
                sysfs_drop_dentry(sd, dentry);
                sysfs_put(sd);
        }
-       up(&dentry->d_inode->i_sem);
+       mutex_unlock(&dentry->d_inode->i_mutex);
 
        remove_dir(dentry);
        /**
         * Drop reference from dget() on entrance.
         */
        dput(dentry);
+       kobj->dentry = NULL;
 }
 
 int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
@@ -313,9 +349,9 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
        down_write(&sysfs_rename_sem);
        parent = kobj->parent->dentry;
 
-       down(&parent->d_inode->i_sem);
+       mutex_lock(&parent->d_inode->i_mutex);
 
-       new_dentry = sysfs_get_dentry(parent, new_name);
+       new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
        if (!IS_ERR(new_dentry)) {
                if (!new_dentry->d_inode) {
                        error = kobject_set_name(kobj, "%s", new_name);
@@ -329,7 +365,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
                        error = -EEXIST;
                dput(new_dentry);
        }
-       up(&parent->d_inode->i_sem);    
+       mutex_unlock(&parent->d_inode->i_mutex);
        up_write(&sysfs_rename_sem);
 
        return error;
@@ -340,9 +376,9 @@ static int sysfs_dir_open(struct inode *inode, struct file *file)
        struct dentry * dentry = file->f_dentry;
        struct sysfs_dirent * parent_sd = dentry->d_fsdata;
 
-       down(&dentry->d_inode->i_sem);
+       mutex_lock(&dentry->d_inode->i_mutex);
        file->private_data = sysfs_new_dirent(parent_sd, NULL);
-       up(&dentry->d_inode->i_sem);
+       mutex_unlock(&dentry->d_inode->i_mutex);
 
        return file->private_data ? 0 : -ENOMEM;
 
@@ -353,9 +389,9 @@ static int sysfs_dir_close(struct inode *inode, struct file *file)
        struct dentry * dentry = file->f_dentry;
        struct sysfs_dirent * cursor = file->private_data;
 
-       down(&dentry->d_inode->i_sem);
+       mutex_lock(&dentry->d_inode->i_mutex);
        list_del_init(&cursor->s_sibling);
-       up(&dentry->d_inode->i_sem);
+       mutex_unlock(&dentry->d_inode->i_mutex);
 
        release_sysfs_dirent(cursor);
 
@@ -431,7 +467,7 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
 {
        struct dentry * dentry = file->f_dentry;
 
-       down(&dentry->d_inode->i_sem);
+       mutex_lock(&dentry->d_inode->i_mutex);
        switch (origin) {
                case 1:
                        offset += file->f_pos;
@@ -439,7 +475,7 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
                        if (offset >= 0)
                                break;
                default:
-                       up(&file->f_dentry->d_inode->i_sem);
+                       mutex_unlock(&file->f_dentry->d_inode->i_mutex);
                        return -EINVAL;
        }
        if (offset != file->f_pos) {
@@ -463,19 +499,14 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
                        list_add_tail(&cursor->s_sibling, p);
                }
        }
-       up(&dentry->d_inode->i_sem);
+       mutex_unlock(&dentry->d_inode->i_mutex);
        return offset;
 }
 
-struct file_operations sysfs_dir_operations = {
+const struct file_operations sysfs_dir_operations = {
        .open           = sysfs_dir_open,
        .release        = sysfs_dir_close,
        .llseek         = sysfs_dir_lseek,
        .read           = generic_read_dir,
        .readdir        = sysfs_readdir,
 };
-
-EXPORT_SYMBOL_GPL(sysfs_create_dir);
-EXPORT_SYMBOL_GPL(sysfs_remove_dir);
-EXPORT_SYMBOL_GPL(sysfs_rename_dir);
-