5 files changed, 92 insertions, 41 deletions

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 006fc64227dd..66f6e58a7e4b 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -61,6 +61,7 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
         int size = dentry->d_inode->i_size;
         loff_t offs = *off;
         int count = min_t(size_t, bytes, PAGE_SIZE);
+        char *temp;
 
         if (size) {
                 if (offs > size)
@@ -69,23 +70,33 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
                         count = size - offs;
         }
 
+        temp = kmalloc(count, GFP_KERNEL);
+        if (!temp)
+                return -ENOMEM;
+
         mutex_lock(&bb->mutex);
 
         count = fill_read(dentry, bb->buffer, offs, count);
-        if (count < 0)
-                goto out_unlock;
+        if (count < 0) {
+                mutex_unlock(&bb->mutex);
+                goto out_free;
+        }
 
-        if (copy_to_user(userbuf, bb->buffer, count)) {
+        memcpy(temp, bb->buffer, count);
+
+        mutex_unlock(&bb->mutex);
+
+        if (copy_to_user(userbuf, temp, count)) {
                 count = -EFAULT;
-                goto out_unlock;
+                goto out_free;
         }
 
         pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
 
         *off = offs + count;
 
- out_unlock:
-        mutex_unlock(&bb->mutex);
+ out_free:
+        kfree(temp);
         return count;
 }
 
@@ -118,6 +129,7 @@ static ssize_t write(struct file *file, const char __user *userbuf,
         int size = dentry->d_inode->i_size;
         loff_t offs = *off;
         int count = min_t(size_t, bytes, PAGE_SIZE);
+        char *temp;
 
         if (size) {
                 if (offs > size)
@@ -126,19 +138,27 @@ static ssize_t write(struct file *file, const char __user *userbuf,
                         count = size - offs;
         }
 
-        mutex_lock(&bb->mutex);
+        temp = kmalloc(count, GFP_KERNEL);
+        if (!temp)
+                return -ENOMEM;
 
-        if (copy_from_user(bb->buffer, userbuf, count)) {
+        if (copy_from_user(temp, userbuf, count)) {
                 count = -EFAULT;
-                goto out_unlock;
+                goto out_free;
         }
 
+        mutex_lock(&bb->mutex);
+
+        memcpy(bb->buffer, temp, count);
+
         count = flush_write(dentry, bb->buffer, offs, count);
+        mutex_unlock(&bb->mutex);
+
         if (count > 0)
                 *off = offs + count;
 
- out_unlock:
-        mutex_unlock(&bb->mutex);
+out_free:
+        kfree(temp);
         return count;
 }
 
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index aedaeba82ae5..3a05a596e3b4 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -370,17 +370,17 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
         memset(acxt, 0, sizeof(*acxt));
         acxt->parent_sd = parent_sd;
 
-        /* Lookup parent inode.  inode initialization and I_NEW
-         * clearing are protected by sysfs_mutex.  By grabbing it and
-         * looking up with _nowait variant, inode state can be
-         * determined reliably.
+        /* Lookup parent inode.  inode initialization is protected by
+         * sysfs_mutex, so inode existence can be determined by
+         * looking up inode while holding sysfs_mutex.
          */
         mutex_lock(&sysfs_mutex);
 
-        inode = ilookup5_nowait(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test,
-                                parent_sd);
+        inode = ilookup5(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test,
+                         parent_sd);
+        if (inode) {
+                WARN_ON(inode->i_state & I_NEW);
 
-        if (inode && !(inode->i_state & I_NEW)) {
                 /* parent inode available */
                 acxt->parent_inode = inode;
 
@@ -393,8 +393,7 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
                         mutex_lock(&inode->i_mutex);
                         mutex_lock(&sysfs_mutex);
                 }
-        } else
-                iput(inode);
+        }
 }
 
 /**
@@ -636,6 +635,7 @@ struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 
         return sd;
 }
+EXPORT_SYMBOL_GPL(sysfs_get_dirent);
 
 static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
                       const char *name, struct sysfs_dirent **p_sd)
@@ -829,16 +829,12 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
         if (!new_dentry)
                 goto out_unlock;
 
-        /* rename kobject and sysfs_dirent */
+        /* rename sysfs_dirent */
         error = -ENOMEM;
         new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
         if (!new_name)
                 goto out_unlock;
 
-        error = kobject_set_name(kobj, "%s", new_name);
-        if (error)
-                goto out_unlock;
-
         dup_name = sd->s_name;
         sd->s_name = new_name;
 
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index c9e4e5091da1..1f4a3f877262 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -19,10 +19,18 @@
 #include <linux/poll.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
+#include <linux/limits.h>
 #include <asm/uaccess.h>
 
 #include "sysfs.h"
 
+/* used in crash dumps to help with debugging */
+static char last_sysfs_file[PATH_MAX];
+void sysfs_printk_last_file(void)
+{
+        printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
+}
+
 /*
  * There's one sysfs_buffer for each open file and one
  * sysfs_open_dirent for each sysfs_dirent with one or more open
@@ -328,6 +336,11 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
         struct sysfs_buffer *buffer;
         struct sysfs_ops *ops;
         int error = -EACCES;
+        char *p;
+
+        p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file));
+        if (p)
+                memmove(last_sysfs_file, p, strlen(p) + 1);
 
         /* need attr_sd for attr and ops, its parent for kobj */
         if (!sysfs_get_active_two(attr_sd))
@@ -440,7 +453,23 @@ static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
         return POLLERR|POLLPRI;
 }
 
-void sysfs_notify(struct kobject *k, char *dir, char *attr)
+void sysfs_notify_dirent(struct sysfs_dirent *sd)
+{
+        struct sysfs_open_dirent *od;
+
+        spin_lock(&sysfs_open_dirent_lock);
+
+        od = sd->s_attr.open;
+        if (od) {
+                atomic_inc(&od->event);
+                wake_up_interruptible(&od->poll);
+        }
+
+        spin_unlock(&sysfs_open_dirent_lock);
+}
+EXPORT_SYMBOL_GPL(sysfs_notify_dirent);
+
+void sysfs_notify(struct kobject *k, const char *dir, const char *attr)
 {
         struct sysfs_dirent *sd = k->sd;
 
@@ -450,19 +479,8 @@ void sysfs_notify(struct kobject *k, char *dir, char *attr)
                 sd = sysfs_find_dirent(sd, dir);
         if (sd && attr)
                 sd = sysfs_find_dirent(sd, attr);
-        if (sd) {
-                struct sysfs_open_dirent *od;
-
-                spin_lock(&sysfs_open_dirent_lock);
-
-                od = sd->s_attr.open;
-                if (od) {
-                        atomic_inc(&od->event);
-                        wake_up_interruptible(&od->poll);
-                }
-
-                spin_unlock(&sysfs_open_dirent_lock);
-        }
+        if (sd)
+                sysfs_notify_dirent(sd);
 
         mutex_unlock(&sysfs_mutex);
 }
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 14f0023984d7..ab343e371d64 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -16,6 +16,7 @@
 #include <linux/mount.h>
 #include <linux/pagemap.h>
 #include <linux/init.h>
+#include <linux/module.h>
 
 #include "sysfs.h"
 
@@ -115,3 +116,17 @@ out_err:
         sysfs_dir_cachep = NULL;
         goto out;
 }
+
+#undef sysfs_get
+struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
+{
+        return __sysfs_get(sd);
+}
+EXPORT_SYMBOL_GPL(sysfs_get);
+
+#undef sysfs_put
+void sysfs_put(struct sysfs_dirent *sd)
+{
+        __sysfs_put(sd);
+}
+EXPORT_SYMBOL_GPL(sysfs_put);
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index a5db496f71c7..93c6d6b27c4d 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -124,7 +124,7 @@ int sysfs_create_subdir(struct kobject *kobj, const char *name,
                         struct sysfs_dirent **p_sd);
 void sysfs_remove_subdir(struct sysfs_dirent *sd);
 
-static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
+static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
 {
         if (sd) {
                 WARN_ON(!atomic_read(&sd->s_count));
@@ -132,12 +132,14 @@ static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
         }
         return sd;
 }
+#define sysfs_get(sd) __sysfs_get(sd)
 
-static inline void sysfs_put(struct sysfs_dirent *sd)
+static inline void __sysfs_put(struct sysfs_dirent *sd)
 {
         if (sd && atomic_dec_and_test(&sd->s_count))
                 release_sysfs_dirent(sd);
 }
+#define sysfs_put(sd) __sysfs_put(sd)
 
 /*
  * inode.c