/*
- * 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
#include <linux/idr.h>
#include <linux/completion.h>
#include <linux/mutex.h>
+#include <linux/slab.h>
#include "sysfs.h"
DEFINE_MUTEX(sysfs_mutex);
-spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_MUTEX(sysfs_rename_mutex);
+DEFINE_SPINLOCK(sysfs_assoc_lock);
-static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(sysfs_ino_lock);
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)
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;
}
/**
* @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)
{
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;
* @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);
-
- 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);
+ struct dentry *dentry = dget(sysfs_sb->s_root);
- spin_unlock(&dcache_lock);
- spin_unlock(&sysfs_assoc_lock);
+ while (dentry->d_fsdata != sd) {
+ struct sysfs_dirent *cur;
+ struct dentry *parent;
- /* 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,
- strlen(cur->s_name));
- dput(parent_dentry);
-
- if (IS_ERR(dentry)) {
- sysfs_put(cur);
- return dentry;
- }
-
- mutex_lock(&sysfs_mutex);
- spin_lock(&sysfs_assoc_lock);
+ parent = dentry;
+ mutex_lock(&parent->d_inode->i_mutex);
+ dentry = lookup_one_noperm(cur->s_name, parent);
+ mutex_unlock(&parent->d_inode->i_mutex);
+ dput(parent);
- /* 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;
}
* RETURNS:
* Pointer to @sd on success, NULL on failure.
*/
-struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
{
if (unlikely(!sd))
return NULL;
* Put an active reference to @sd. This function is noop if @sd
* is NULL.
*/
-void sysfs_put_active(struct sysfs_dirent *sd)
+static void sysfs_put_active(struct sysfs_dirent *sd)
{
struct completion *cmpl;
int v;
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);
{
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);
}
-static struct dentry_operations sysfs_dentry_ops = {
+static const struct dentry_operations sysfs_dentry_ops = {
.d_iput = sysfs_d_iput,
};
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;
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;
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;
mutex_lock(&inode->i_mutex);
mutex_lock(&sysfs_mutex);
}
- } else
- iput(inode);
+ }
}
/**
- * sysfs_add_one - add sysfs_dirent to parent
+ * __sysfs_add_one - add sysfs_dirent to parent without warning
* @acxt: addrm context to use
* @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
* 0 on success, -EEXIST if entry with the given name already
* exists.
*/
-int 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))
return -EEXIST;
}
/**
- * sysfs_remove_one - remove sysfs_dirent from parent
+ * sysfs_pathname - return full path to sysfs dirent
+ * @sd: sysfs_dirent whose path we want
+ * @path: caller allocated buffer
+ *
+ * Gives the name "/" to the sysfs_root entry; any path returned
+ * is relative to wherever sysfs is mounted.
+ *
+ * XXX: does no error checking on @path size
+ */
+static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
+{
+ if (sd->s_parent) {
+ sysfs_pathname(sd->s_parent, path);
+ strcat(path, "/");
+ }
+ strcat(path, sd->s_name);
+ return path;
+}
+
+/**
+ * sysfs_add_one - add sysfs_dirent to parent
* @acxt: addrm context to use
* @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 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
+ * passed the same @acxt as passed to sysfs_addrm_start().
+ *
+ * LOCKING:
+ * Determined by sysfs_addrm_start().
+ *
+ * RETURNS:
+ * 0 on success, -EEXIST if entry with the given name already
+ * exists.
+ */
+int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
+{
+ int ret;
+
+ ret = __sysfs_add_one(acxt, sd);
+ if (ret == -EEXIST) {
+ char *path = kzalloc(PATH_MAX, GFP_KERNEL);
+ WARN(1, KERN_WARNING
+ "sysfs: cannot create duplicate filename '%s'\n",
+ (path == NULL) ? sd->s_name :
+ strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
+ sd->s_name));
+ kfree(path);
+ }
+
+ return ret;
+}
+
+/**
+ * sysfs_remove_one - remove sysfs_dirent from parent
+ * @acxt: addrm context to use
+ * @sd: sysfs_dirent to be removed
+ *
* 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
* 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);
-
- 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);
}
/**
*
* 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);
sysfs_drop_dentry(sd);
sysfs_deactivate(sd);
+ unmap_bin_file(sd);
sysfs_put(sd);
}
-
- return acxt->cnt;
}
/**
{
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;
}
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)
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);
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)
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 inode *inode;
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))
- break;
+ sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
/* no such entry */
- if (!sd)
+ if (!sd) {
+ ret = ERR_PTR(-ENOENT);
goto out_unlock;
+ }
/* attach dentry and inode */
inode = sysfs_get_inode(sd);
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);
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)
+ if (sysfs_type(sd) != SYSFS_DIR)
sysfs_remove_one(&acxt, sd);
else
pos = &(*pos)->s_sibling;
int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
{
- struct sysfs_dirent *sd;
+ struct sysfs_dirent *sd = kobj->sd;
struct dentry *parent = NULL;
struct dentry *old_dentry = NULL, *new_dentry = NULL;
const char *dup_name = NULL;
int error;
+ mutex_lock(&sysfs_rename_mutex);
+
+ error = 0;
+ if (strcmp(sd->s_name, new_name) == 0)
+ goto out; /* nothing to rename */
+
/* get the original dentry */
- sd = kobj->sd;
old_dentry = sysfs_get_dentry(sd);
if (IS_ERR(old_dentry)) {
error = PTR_ERR(old_dentry);
- goto out_dput;
+ old_dentry = NULL;
+ goto out;
}
parent = old_dentry->d_parent;
/* lock parent and get dentry for new name */
mutex_lock(&parent->d_inode->i_mutex);
+ mutex_lock(&sysfs_mutex);
- new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
- if (IS_ERR(new_dentry)) {
- error = PTR_ERR(new_dentry);
- goto out_unlock;
- }
-
- error = -EINVAL;
- if (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 */
+ /* rename sysfs_dirent */
error = -ENOMEM;
new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
- goto out_drop;
-
- error = kobject_set_name(kobj, "%s", new_name);
- if (error)
- goto out_drop;
+ goto out_unlock;
- mutex_lock(&sysfs_mutex);
dup_name = sd->s_name;
sd->s_name = new_name;
- mutex_unlock(&sysfs_mutex);
/* rename */
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
+ d_move(old_dentry, new_dentry);
error = 0;
- goto out_unlock;
-
- out_drop:
- d_drop(new_dentry);
out_unlock:
+ mutex_unlock(&sysfs_mutex);
mutex_unlock(&parent->d_inode->i_mutex);
- out_dput:
kfree(dup_name);
dput(old_dentry);
dput(new_dentry);
+ out:
+ mutex_unlock(&sysfs_rename_mutex);
return error;
}
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;
+ old_dentry = NULL;
+ 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;
+ new_parent = NULL;
+ 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(kobject_name(kobj), new_parent, strlen(kobject_name(kobj)));
- 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);
- dput(new_dentry);
+ d_move(old_dentry, 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)
{
{
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;
-
- filp->f_pos++;
- }
+ }
+ if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) {
+ mutex_lock(&sysfs_mutex);
- /* put cursor back in */
- cursor->s_sibling = *pos;
- *pos = cursor;
+ /* 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;
- mutex_unlock(&sysfs_mutex);
- }
- return 0;
-}
+ for ( ; pos; pos = pos->s_sibling) {
+ const char * name;
+ int len;
-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;
+ return 0;
}
+
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,
+ .llseek = generic_file_llseek,
};
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff