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-rw-r--r--fs/sysfs/dir.c754
1 files changed, 199 insertions, 555 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 83e76b3813c9..9161db4d6b5c 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -1,5 +1,13 @@
/*
- * dir.c - Operations for sysfs directories.
+ * fs/sysfs/dir.c - sysfs core and dir operation implementation
+ *
+ * Copyright (c) 2001-3 Patrick Mochel
+ * Copyright (c) 2007 SUSE Linux Products GmbH
+ * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Please see Documentation/filesystems/sysfs.txt for more information.
*/
#undef DEBUG
@@ -11,10 +19,11 @@
#include <linux/namei.h>
#include <linux/idr.h>
#include <linux/completion.h>
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
#include "sysfs.h"
DEFINE_MUTEX(sysfs_mutex);
+DEFINE_MUTEX(sysfs_rename_mutex);
spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
@@ -25,18 +34,28 @@ static DEFINE_IDA(sysfs_ino_ida);
* @sd: sysfs_dirent of interest
*
* Link @sd into its sibling list which starts from
- * sd->s_parent->s_children.
+ * sd->s_parent->s_dir.children.
*
* Locking:
* mutex_lock(sysfs_mutex)
*/
-void sysfs_link_sibling(struct sysfs_dirent *sd)
+static void sysfs_link_sibling(struct sysfs_dirent *sd)
{
struct sysfs_dirent *parent_sd = sd->s_parent;
+ struct sysfs_dirent **pos;
BUG_ON(sd->s_sibling);
- sd->s_sibling = parent_sd->s_children;
- parent_sd->s_children = sd;
+
+ /* Store directory entries in order by ino. This allows
+ * readdir to properly restart without having to add a
+ * cursor into the s_dir.children list.
+ */
+ for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) {
+ if (sd->s_ino < (*pos)->s_ino)
+ break;
+ }
+ sd->s_sibling = *pos;
+ *pos = sd;
}
/**
@@ -44,16 +63,17 @@ void sysfs_link_sibling(struct sysfs_dirent *sd)
* @sd: sysfs_dirent of interest
*
* Unlink @sd from its sibling list which starts from
- * sd->s_parent->s_children.
+ * sd->s_parent->s_dir.children.
*
* Locking:
* mutex_lock(sysfs_mutex)
*/
-void sysfs_unlink_sibling(struct sysfs_dirent *sd)
+static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
{
struct sysfs_dirent **pos;
- for (pos = &sd->s_parent->s_children; *pos; pos = &(*pos)->s_sibling) {
+ for (pos = &sd->s_parent->s_dir.children; *pos;
+ pos = &(*pos)->s_sibling) {
if (*pos == sd) {
*pos = sd->s_sibling;
sd->s_sibling = NULL;
@@ -67,96 +87,39 @@ void sysfs_unlink_sibling(struct sysfs_dirent *sd)
* @sd: sysfs_dirent of interest
*
* Get dentry for @sd. Dentry is looked up if currently not
- * present. This function climbs sysfs_dirent tree till it
- * reaches a sysfs_dirent with valid dentry attached and descends
- * down from there looking up dentry for each step.
+ * present. This function descends from the root looking up
+ * dentry for each step.
*
* LOCKING:
- * Kernel thread context (may sleep)
+ * mutex_lock(sysfs_rename_mutex)
*
* RETURNS:
* Pointer to found dentry on success, ERR_PTR() value on error.
*/
struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
{
- struct sysfs_dirent *cur;
- struct dentry *parent_dentry, *dentry;
- int i, depth;
-
- /* Find the first parent which has valid s_dentry and get the
- * dentry.
- */
- mutex_lock(&sysfs_mutex);
- restart0:
- spin_lock(&sysfs_assoc_lock);
- restart1:
- spin_lock(&dcache_lock);
+ struct dentry *dentry = dget(sysfs_sb->s_root);
- dentry = NULL;
- depth = 0;
- cur = sd;
- while (!cur->s_dentry || !cur->s_dentry->d_inode) {
- if (cur->s_flags & SYSFS_FLAG_REMOVED) {
- dentry = ERR_PTR(-ENOENT);
- depth = 0;
- break;
- }
- cur = cur->s_parent;
- depth++;
- }
- if (!IS_ERR(dentry))
- dentry = dget_locked(cur->s_dentry);
+ while (dentry->d_fsdata != sd) {
+ struct sysfs_dirent *cur;
+ struct dentry *parent;
- spin_unlock(&dcache_lock);
- spin_unlock(&sysfs_assoc_lock);
-
- /* from the found dentry, look up depth times */
- while (depth--) {
- /* find and get depth'th ancestor */
- for (cur = sd, i = 0; cur && i < depth; i++)
+ /* find the first ancestor which hasn't been looked up */
+ cur = sd;
+ while (cur->s_parent != dentry->d_fsdata)
cur = cur->s_parent;
- /* This can happen if tree structure was modified due
- * to move/rename. Restart.
- */
- if (i != depth) {
- dput(dentry);
- goto restart0;
- }
-
- sysfs_get(cur);
-
- mutex_unlock(&sysfs_mutex);
-
/* look it up */
- parent_dentry = dentry;
- dentry = lookup_one_len_kern(cur->s_name, parent_dentry,
+ parent = dentry;
+ mutex_lock(&parent->d_inode->i_mutex);
+ dentry = lookup_one_len_kern(cur->s_name, parent,
strlen(cur->s_name));
- dput(parent_dentry);
-
- if (IS_ERR(dentry)) {
- sysfs_put(cur);
- return dentry;
- }
+ mutex_unlock(&parent->d_inode->i_mutex);
+ dput(parent);
- mutex_lock(&sysfs_mutex);
- spin_lock(&sysfs_assoc_lock);
-
- /* This, again, can happen if tree structure has
- * changed and we looked up the wrong thing. Restart.
- */
- if (cur->s_dentry != dentry) {
- dput(dentry);
- sysfs_put(cur);
- goto restart1;
- }
-
- spin_unlock(&sysfs_assoc_lock);
-
- sysfs_put(cur);
+ if (IS_ERR(dentry))
+ break;
}
-
- mutex_unlock(&sysfs_mutex);
return dentry;
}
@@ -319,7 +282,7 @@ void release_sysfs_dirent(struct sysfs_dirent * sd)
parent_sd = sd->s_parent;
if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
- sysfs_put(sd->s_elem.symlink.target_sd);
+ sysfs_put(sd->s_symlink.target_sd);
if (sysfs_type(sd) & SYSFS_COPY_NAME)
kfree(sd->s_name);
kfree(sd->s_iattr);
@@ -335,22 +298,7 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
- if (sd) {
- /* sd->s_dentry is protected with sysfs_assoc_lock.
- * This allows sysfs_drop_dentry() to dereference it.
- */
- spin_lock(&sysfs_assoc_lock);
-
- /* The dentry might have been deleted or another
- * lookup could have happened updating sd->s_dentry to
- * point the new dentry. Ignore if it isn't pointing
- * to this dentry.
- */
- if (sd->s_dentry == dentry)
- sd->s_dentry = NULL;
- spin_unlock(&sysfs_assoc_lock);
- sysfs_put(sd);
- }
+ sysfs_put(sd);
iput(inode);
}
@@ -378,7 +326,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
atomic_set(&sd->s_count, 1);
atomic_set(&sd->s_active, 0);
- atomic_set(&sd->s_event, 1);
sd->s_name = name;
sd->s_mode = mode;
@@ -393,30 +340,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
return NULL;
}
-/**
- * sysfs_attach_dentry - associate sysfs_dirent with dentry
- * @sd: target sysfs_dirent
- * @dentry: dentry to associate
- *
- * Associate @sd with @dentry. This is protected by
- * sysfs_assoc_lock to avoid race with sysfs_d_iput().
- *
- * LOCKING:
- * mutex_lock(sysfs_mutex)
- */
-static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
-{
- dentry->d_op = &sysfs_dentry_ops;
- dentry->d_fsdata = sysfs_get(sd);
-
- /* protect sd->s_dentry against sysfs_d_iput */
- spin_lock(&sysfs_assoc_lock);
- sd->s_dentry = dentry;
- spin_unlock(&sysfs_assoc_lock);
-
- d_rehash(dentry);
-}
-
static int sysfs_ilookup_test(struct inode *inode, void *arg)
{
struct sysfs_dirent *sd = arg;
@@ -480,10 +403,8 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
* @sd: sysfs_dirent to be added
*
* Get @acxt->parent_sd and set sd->s_parent to it and increment
- * nlink of parent inode if @sd is a directory. @sd is NOT
- * linked into the children list of the parent. The caller
- * should invoke sysfs_link_sibling() after this function
- * completes if @sd needs to be on the children list.
+ * nlink of parent inode if @sd is a directory and link into the
+ * children list of the parent.
*
* This function should be called between calls to
* sysfs_addrm_start() and sysfs_addrm_finish() and should be
@@ -491,15 +412,30 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
*
* LOCKING:
* Determined by sysfs_addrm_start().
+ *
+ * RETURNS:
+ * 0 on success, -EEXIST if entry with the given name already
+ * exists.
*/
-void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
+ if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) {
+ printk(KERN_WARNING "sysfs: duplicate filename '%s' "
+ "can not be created\n", sd->s_name);
+ WARN_ON(1);
+ return -EEXIST;
+ }
+
sd->s_parent = sysfs_get(acxt->parent_sd);
if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
inc_nlink(acxt->parent_inode);
acxt->cnt++;
+
+ sysfs_link_sibling(sd);
+
+ return 0;
}
/**
@@ -508,9 +444,7 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
* @sd: sysfs_dirent to be added
*
* Mark @sd removed and drop nlink of parent inode if @sd is a
- * directory. @sd is NOT unlinked from the children list of the
- * parent. The caller is repsonsible for removing @sd from the
- * children list before calling this function.
+ * directory. @sd is unlinked from the children list.
*
* This function should be called between calls to
* sysfs_addrm_start() and sysfs_addrm_finish() and should be
@@ -521,7 +455,9 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
*/
void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
- BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED));
+ BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
+
+ sysfs_unlink_sibling(sd);
sd->s_flags |= SYSFS_FLAG_REMOVED;
sd->s_sibling = acxt->removed;
@@ -540,53 +476,49 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
* Drop dentry for @sd. @sd must have been unlinked from its
* parent on entry to this function such that it can't be looked
* up anymore.
- *
- * @sd->s_dentry which is protected with sysfs_assoc_lock points
- * to the currently associated dentry but we're not holding a
- * reference to it and racing with dput(). Grab dcache_lock and
- * verify dentry before dropping it. If @sd->s_dentry is NULL or
- * dput() beats us, no need to bother.
*/
static void sysfs_drop_dentry(struct sysfs_dirent *sd)
{
- struct dentry *dentry = NULL;
struct inode *inode;
+ struct dentry *dentry;
- /* We're not holding a reference to ->s_dentry dentry but the
- * field will stay valid as long as sysfs_assoc_lock is held.
+ inode = ilookup(sysfs_sb, sd->s_ino);
+ if (!inode)
+ return;
+
+ /* Drop any existing dentries associated with sd.
+ *
+ * For the dentry to be properly freed we need to grab a
+ * reference to the dentry under the dcache lock, unhash it,
+ * and then put it. The playing with the dentry count allows
+ * dput to immediately free the dentry if it is not in use.
*/
- spin_lock(&sysfs_assoc_lock);
+repeat:
spin_lock(&dcache_lock);
-
- /* drop dentry if it's there and dput() didn't kill it yet */
- if (sd->s_dentry && sd->s_dentry->d_inode) {
- dentry = dget_locked(sd->s_dentry);
+ list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+ if (d_unhashed(dentry))
+ continue;
+ dget_locked(dentry);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_lock);
+ dput(dentry);
+ goto repeat;
}
-
spin_unlock(&dcache_lock);
- spin_unlock(&sysfs_assoc_lock);
-
- /* dentries for shadowed inodes are pinned, unpin */
- if (dentry && sysfs_is_shadowed_inode(dentry->d_inode))
- dput(dentry);
- dput(dentry);
/* adjust nlink and update timestamp */
- inode = ilookup(sysfs_sb, sd->s_ino);
- if (inode) {
- mutex_lock(&inode->i_mutex);
+ mutex_lock(&inode->i_mutex);
- inode->i_ctime = CURRENT_TIME;
+ inode->i_ctime = CURRENT_TIME;
+ drop_nlink(inode);
+ if (sysfs_type(sd) == SYSFS_DIR)
drop_nlink(inode);
- if (sysfs_type(sd) == SYSFS_DIR)
- drop_nlink(inode);
- mutex_unlock(&inode->i_mutex);
- iput(inode);
- }
+ mutex_unlock(&inode->i_mutex);
+
+ iput(inode);
}
/**
@@ -599,11 +531,8 @@ static void sysfs_drop_dentry(struct sysfs_dirent *sd)
*
* LOCKING:
* All mutexes acquired by sysfs_addrm_start() are released.
- *
- * RETURNS:
- * Number of added/removed sysfs_dirents since sysfs_addrm_start().
*/
-int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
+void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
{
/* release resources acquired by sysfs_addrm_start() */
mutex_unlock(&sysfs_mutex);
@@ -629,8 +558,6 @@ int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
sysfs_deactivate(sd);
sysfs_put(sd);
}
-
- return acxt->cnt;
}
/**
@@ -651,8 +578,8 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
{
struct sysfs_dirent *sd;
- for (sd = parent_sd->s_children; sd; sd = sd->s_sibling)
- if (sysfs_type(sd) && !strcmp(sd->s_name, name))
+ for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling)
+ if (!strcmp(sd->s_name, name))
return sd;
return NULL;
}
@@ -690,28 +617,25 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
struct sysfs_addrm_cxt acxt;
struct sysfs_dirent *sd;
+ int rc;
/* allocate */
sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
if (!sd)
return -ENOMEM;
- sd->s_elem.dir.kobj = kobj;
+ sd->s_dir.kobj = kobj;
/* link in */
sysfs_addrm_start(&acxt, parent_sd);
+ rc = sysfs_add_one(&acxt, sd);
+ sysfs_addrm_finish(&acxt);
- if (!sysfs_find_dirent(parent_sd, name)) {
- sysfs_add_one(&acxt, sd);
- sysfs_link_sibling(sd);
- }
-
- if (!sysfs_addrm_finish(&acxt)) {
+ if (rc == 0)
+ *p_sd = sd;
+ else
sysfs_put(sd);
- return -EEXIST;
- }
- *p_sd = sd;
- return 0;
+ return rc;
}
int sysfs_create_subdir(struct kobject *kobj, const char *name,
@@ -723,24 +647,18 @@ int sysfs_create_subdir(struct kobject *kobj, const char *name,
/**
* sysfs_create_dir - create a directory for an object.
* @kobj: object we're creating directory for.
- * @shadow_parent: parent object.
*/
-int sysfs_create_dir(struct kobject *kobj,
- struct sysfs_dirent *shadow_parent_sd)
+int sysfs_create_dir(struct kobject * kobj)
{
struct sysfs_dirent *parent_sd, *sd;
int error = 0;
BUG_ON(!kobj);
- if (shadow_parent_sd)
- parent_sd = shadow_parent_sd;
- else if (kobj->parent)
+ if (kobj->parent)
parent_sd = kobj->parent->sd;
- else if (sysfs_mount && sysfs_mount->mnt_sb)
- parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata;
else
- return -EFAULT;
+ parent_sd = &sysfs_root;
error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd);
if (!error)
@@ -748,39 +666,20 @@ int sysfs_create_dir(struct kobject *kobj,
return error;
}
-static int sysfs_count_nlink(struct sysfs_dirent *sd)
-{
- struct sysfs_dirent *child;
- int nr = 0;
-
- for (child = sd->s_children; child; child = child->s_sibling)
- if (sysfs_type(child) == SYSFS_DIR)
- nr++;
- return nr + 2;
-}
-
static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct dentry *ret = NULL;
- struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
- struct sysfs_dirent * sd;
- struct bin_attribute *bin_attr;
+ struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata;
+ struct sysfs_dirent *sd;
struct inode *inode;
- int found = 0;
mutex_lock(&sysfs_mutex);
- for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
- if (sysfs_type(sd) &&
- !strcmp(sd->s_name, dentry->d_name.name)) {
- found = 1;
- break;
- }
- }
+ sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
/* no such entry */
- if (!found)
+ if (!sd)
goto out_unlock;
/* attach dentry and inode */
@@ -790,33 +689,11 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
goto out_unlock;
}
- if (inode->i_state & I_NEW) {
- /* initialize inode according to type */
- switch (sysfs_type(sd)) {
- case SYSFS_DIR:
- inode->i_op = &sysfs_dir_inode_operations;
- inode->i_fop = &sysfs_dir_operations;
- inode->i_nlink = sysfs_count_nlink(sd);
- break;
- case SYSFS_KOBJ_ATTR:
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &sysfs_file_operations;
- break;
- case SYSFS_KOBJ_BIN_ATTR:
- bin_attr = sd->s_elem.bin_attr.bin_attr;
- inode->i_size = bin_attr->size;
- inode->i_fop = &bin_fops;
- break;
- case SYSFS_KOBJ_LINK:
- inode->i_op = &sysfs_symlink_inode_operations;
- break;
- default:
- BUG();
- }
- }
-
- sysfs_instantiate(dentry, inode);
- sysfs_attach_dentry(sd, dentry);
+ /* instantiate and hash dentry */
+ dentry->d_op = &sysfs_dentry_ops;
+ dentry->d_fsdata = sysfs_get(sd);
+ d_instantiate(dentry, inode);
+ d_rehash(dentry);
out_unlock:
mutex_unlock(&sysfs_mutex);
@@ -833,7 +710,6 @@ static void remove_dir(struct sysfs_dirent *sd)
struct sysfs_addrm_cxt acxt;
sysfs_addrm_start(&acxt, sd->s_parent);
- sysfs_unlink_sibling(sd);
sysfs_remove_one(&acxt, sd);
sysfs_addrm_finish(&acxt);
}
@@ -854,15 +730,13 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
sysfs_addrm_start(&acxt, dir_sd);
- pos = &dir_sd->s_children;
+ pos = &dir_sd->s_dir.children;
while (*pos) {
struct sysfs_dirent *sd = *pos;
- if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) {
- *pos = sd->s_sibling;
- sd->s_sibling = NULL;
+ if (sysfs_type(sd) != SYSFS_DIR)
sysfs_remove_one(&acxt, sd);
- } else
+ else
pos = &(*pos)->s_sibling;
}
sysfs_addrm_finish(&acxt);
@@ -890,90 +764,68 @@ void sysfs_remove_dir(struct kobject * kobj)
__sysfs_remove_dir(sd);
}
-int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
- const char *new_name)
+int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
{
struct sysfs_dirent *sd = kobj->sd;
- struct dentry *new_parent = NULL;
+ struct dentry *parent = NULL;
struct dentry *old_dentry = NULL, *new_dentry = NULL;
const char *dup_name = NULL;
int error;
- /* get dentries */
+ mutex_lock(&sysfs_rename_mutex);
+
+ error = 0;
+ if (strcmp(sd->s_name, new_name) == 0)
+ goto out; /* nothing to rename */
+
+ /* get the original dentry */
old_dentry = sysfs_get_dentry(sd);
if (IS_ERR(old_dentry)) {
error = PTR_ERR(old_dentry);
- goto out_dput;
- }
-
- new_parent = sysfs_get_dentry(new_parent_sd);
- if (IS_ERR(new_parent)) {
- error = PTR_ERR(new_parent);
- goto out_dput;
+ goto out;
}
- /* lock new_parent and get dentry for new name */
- mutex_lock(&new_parent->d_inode->i_mutex);
+ parent = old_dentry->d_parent;
- new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
- if (IS_ERR(new_dentry)) {
- error = PTR_ERR(new_dentry);
- goto out_unlock;
- }
+ /* lock parent and get dentry for new name */
+ mutex_lock(&parent->d_inode->i_mutex);
+ mutex_lock(&sysfs_mutex);
- /* By allowing two different directories with the same
- * d_parent we allow this routine to move between different
- * shadows of the same directory
- */
- error = -EINVAL;
- if (old_dentry->d_parent->d_inode != new_parent->d_inode ||
- new_dentry->d_parent->d_inode != new_parent->d_inode ||
- old_dentry == new_dentry)
+ error = -EEXIST;
+ if (sysfs_find_dirent(sd->s_parent, new_name))
goto out_unlock;
- error = -EEXIST;
- if (new_dentry->d_inode)
+ error = -ENOMEM;
+ new_dentry = d_alloc_name(parent, new_name);
+ if (!new_dentry)
goto out_unlock;
/* rename kobject and sysfs_dirent */
error = -ENOMEM;
new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
- goto out_drop;
+ goto out_unlock;
error = kobject_set_name(kobj, "%s", new_name);
if (error)
- goto out_drop;
-
- mutex_lock(&sysfs_mutex);
+ goto out_unlock;
dup_name = sd->s_name;
sd->s_name = new_name;
- /* move under the new parent */
+ /* rename */
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
-
- sysfs_unlink_sibling(sd);
- sysfs_get(new_parent_sd);
- sysfs_put(sd->s_parent);
- sd->s_parent = new_parent_sd;
- sysfs_link_sibling(sd);
-
- mutex_unlock(&sysfs_mutex);
+ d_move(old_dentry, new_dentry);
error = 0;
- goto out_unlock;
-
- out_drop:
- d_drop(new_dentry);
out_unlock:
- mutex_unlock(&new_parent->d_inode->i_mutex);
- out_dput:
+ mutex_unlock(&sysfs_mutex);
+ mutex_unlock(&parent->d_inode->i_mutex);
kfree(dup_name);
- dput(new_parent);
dput(old_dentry);
dput(new_dentry);
+ out:
+ mutex_unlock(&sysfs_rename_mutex);
return error;
}
@@ -985,96 +837,69 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
struct dentry *old_dentry = NULL, *new_dentry = NULL;
int error;
+ mutex_lock(&sysfs_rename_mutex);
BUG_ON(!sd->s_parent);
new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root;
+ error = 0;
+ if (sd->s_parent == new_parent_sd)
+ goto out; /* nothing to move */
+
/* get dentries */
old_dentry = sysfs_get_dentry(sd);
if (IS_ERR(old_dentry)) {
error = PTR_ERR(old_dentry);
- goto out_dput;
+ goto out;
}
- old_parent = sd->s_parent->s_dentry;
+ old_parent = old_dentry->d_parent;
new_parent = sysfs_get_dentry(new_parent_sd);
if (IS_ERR(new_parent)) {
error = PTR_ERR(new_parent);
- goto out_dput;
+ goto out;
}
- if (old_parent->d_inode == new_parent->d_inode) {
- error = 0;
- goto out_dput; /* nothing to move */
- }
again:
mutex_lock(&old_parent->d_inode->i_mutex);
if (!mutex_trylock(&new_parent->d_inode->i_mutex)) {
mutex_unlock(&old_parent->d_inode->i_mutex);
goto again;
}
+ mutex_lock(&sysfs_mutex);
- new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name));
- if (IS_ERR(new_dentry)) {
- error = PTR_ERR(new_dentry);
+ error = -EEXIST;
+ if (sysfs_find_dirent(new_parent_sd, sd->s_name))
goto out_unlock;
- } else
- error = 0;
+
+ error = -ENOMEM;
+ new_dentry = d_alloc_name(new_parent, sd->s_name);
+ if (!new_dentry)
+ goto out_unlock;
+
+ error = 0;
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
+ d_move(old_dentry, new_dentry);
dput(new_dentry);
/* Remove from old parent's list and insert into new parent's list. */
- mutex_lock(&sysfs_mutex);
-
sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
- mutex_unlock(&sysfs_mutex);
-
out_unlock:
+ mutex_unlock(&sysfs_mutex);
mutex_unlock(&new_parent->d_inode->i_mutex);
mutex_unlock(&old_parent->d_inode->i_mutex);
- out_dput:
+ out:
dput(new_parent);
dput(old_dentry);
dput(new_dentry);
+ mutex_unlock(&sysfs_rename_mutex);
return error;
}
-static int sysfs_dir_open(struct inode *inode, struct file *file)
-{
- struct dentry * dentry = file->f_path.dentry;
- struct sysfs_dirent * parent_sd = dentry->d_fsdata;
- struct sysfs_dirent * sd;
-
- sd = sysfs_new_dirent("_DIR_", 0, 0);
- if (sd) {
- mutex_lock(&sysfs_mutex);
- sd->s_parent = sysfs_get(parent_sd);
- sysfs_link_sibling(sd);
- mutex_unlock(&sysfs_mutex);
- }
-
- file->private_data = sd;
- return sd ? 0 : -ENOMEM;
-}
-
-static int sysfs_dir_close(struct inode *inode, struct file *file)
-{
- struct sysfs_dirent * cursor = file->private_data;
-
- mutex_lock(&sysfs_mutex);
- sysfs_unlink_sibling(cursor);
- mutex_unlock(&sysfs_mutex);
-
- release_sysfs_dirent(cursor);
-
- return 0;
-}
-
/* Relationship between s_mode and the DT_xxx types */
static inline unsigned char dt_type(struct sysfs_dirent *sd)
{
@@ -1085,232 +910,51 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
- struct sysfs_dirent *cursor = filp->private_data;
- struct sysfs_dirent **pos;
+ struct sysfs_dirent *pos;
ino_t ino;
- int i = filp->f_pos;
- switch (i) {
- case 0:
- ino = parent_sd->s_ino;
- if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
- break;
+ if (filp->f_pos == 0) {
+ ino = parent_sd->s_ino;
+ if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
- i++;
- /* fallthrough */
- case 1:
- if (parent_sd->s_parent)
- ino = parent_sd->s_parent->s_ino;
- else
- ino = parent_sd->s_ino;
- if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
- break;
+ }
+ if (filp->f_pos == 1) {
+ if (parent_sd->s_parent)
+ ino = parent_sd->s_parent->s_ino;
+ else
+ ino = parent_sd->s_ino;
+ if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
- i++;
- /* fallthrough */
- default:
- mutex_lock(&sysfs_mutex);
-
- pos = &parent_sd->s_children;
- while (*pos != cursor)
- pos = &(*pos)->s_sibling;
-
- /* unlink cursor */
- *pos = cursor->s_sibling;
-
- if (filp->f_pos == 2)
- pos = &parent_sd->s_children;
-
- for ( ; *pos; pos = &(*pos)->s_sibling) {
- struct sysfs_dirent *next = *pos;
- const char * name;
- int len;
-
- if (!sysfs_type(next))
- continue;
-
- name = next->s_name;
- len = strlen(name);
- ino = next->s_ino;
-
- if (filldir(dirent, name, len, filp->f_pos, ino,
- dt_type(next)) < 0)
- break;
+ }
+ if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) {
+ mutex_lock(&sysfs_mutex);
- filp->f_pos++;
- }
+ /* Skip the dentries we have already reported */
+ pos = parent_sd->s_dir.children;
+ while (pos && (filp->f_pos > pos->s_ino))
+ pos = pos->s_sibling;
- /* put cursor back in */
- cursor->s_sibling = *pos;
- *pos = cursor;
+ for ( ; pos; pos = pos->s_sibling) {
+ const char * name;
+ int len;
- mutex_unlock(&sysfs_mutex);
- }
- return 0;
-}
-
-static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
-{
- struct dentry * dentry = file->f_path.dentry;
+ name = pos->s_name;
+ len = strlen(name);
+ filp->f_pos = ino = pos->s_ino;
- switch (origin) {
- case 1:
- offset += file->f_pos;
- case 0:
- if (offset >= 0)
+ if (filldir(dirent, name, len, filp->f_pos, ino,
+ dt_type(pos)) < 0)
break;
- default:
- return -EINVAL;
- }
- if (offset != file->f_pos) {
- mutex_lock(&sysfs_mutex);
-
- file->f_pos = offset;
- if (file->f_pos >= 2) {
- struct sysfs_dirent *sd = dentry->d_fsdata;
- struct sysfs_dirent *cursor = file->private_data;
- struct sysfs_dirent **pos;
- loff_t n = file->f_pos - 2;
-
- sysfs_unlink_sibling(cursor);
-
- pos = &sd->s_children;
- while (n && *pos) {
- struct sysfs_dirent *next = *pos;
- if (sysfs_type(next))
- n--;
- pos = &(*pos)->s_sibling;
- }
-
- cursor->s_sibling = *pos;
- *pos = cursor;
}
-
+ if (!pos)
+ filp->f_pos = INT_MAX;
mutex_unlock(&sysfs_mutex);
}
-
- return offset;
-}
-
-
-/**
- * sysfs_make_shadowed_dir - Setup so a directory can be shadowed
- * @kobj: object we're creating shadow of.
- */
-
-int sysfs_make_shadowed_dir(struct kobject *kobj,
- void * (*follow_link)(struct dentry *, struct nameidata *))
-{
- struct dentry *dentry;
- struct inode *inode;
- struct inode_operations *i_op;
-
- /* get dentry for @kobj->sd, dentry of a shadowed dir is pinned */
- dentry = sysfs_get_dentry(kobj->sd);
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
-
- inode = dentry->d_inode;
- if (inode->i_op != &sysfs_dir_inode_operations) {
- dput(dentry);
- return -EINVAL;
- }
-
- i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
- if (!i_op)
- return -ENOMEM;
-
- memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
- i_op->follow_link = follow_link;
-
- /* Locking of inode->i_op?
- * Since setting i_op is a single word write and they
- * are atomic we should be ok here.
- */
- inode->i_op = i_op;
return 0;
}
-/**
- * sysfs_create_shadow_dir - create a shadow directory for an object.
- * @kobj: object we're creating directory for.
- *
- * sysfs_make_shadowed_dir must already have been called on this
- * directory.
- */
-
-struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj)
-{
- struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
- struct dentry *dir, *parent, *shadow;
- struct inode *inode;
- struct sysfs_dirent *sd;
- struct sysfs_addrm_cxt acxt;
-
- dir = sysfs_get_dentry(kobj->sd);
- if (IS_ERR(dir)) {
- sd = (void *)dir;
- goto out;
- }
- parent = dir->d_parent;
-
- inode = dir->d_inode;
- sd = ERR_PTR(-EINVAL);
- if (!sysfs_is_shadowed_inode(inode))
- goto out_dput;
-
- shadow = d_alloc(parent, &dir->d_name);
- if (!shadow)
- goto nomem;
-
- sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
- if (!sd)
- goto nomem;
- sd->s_elem.dir.kobj = kobj;
-
- sysfs_addrm_start(&acxt, parent_sd);
-
- /* add but don't link into children list */
- sysfs_add_one(&acxt, sd);
-
- /* attach and instantiate dentry */
- sysfs_attach_dentry(sd, shadow);
- d_instantiate(shadow, igrab(inode));
- inc_nlink(inode); /* tj: synchronization? */
-
- sysfs_addrm_finish(&acxt);
-
- dget(shadow); /* Extra count - pin the dentry in core */
-
- goto out_dput;
-
- nomem:
- dput(shadow);
- sd = ERR_PTR(-ENOMEM);
- out_dput:
- dput(dir);
- out:
- return sd;
-}
-
-/**
- * sysfs_remove_shadow_dir - remove an object's directory.
- * @shadow_sd: sysfs_dirent of shadow directory
- *
- * The only thing special about this is that we remove any files in
- * the directory before we remove the directory, and we've inlined
- * what used to be sysfs_rmdir() below, instead of calling separately.
- */
-
-void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd)
-{
- __sysfs_remove_dir(shadow_sd);
-}
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,
};