sysfs, kernfs: move dir core code to fs/kernfs/dir.c
Move core dir code to fs/kernfs/dir.c. fs/sysfs/dir.c now only
contains sysfs_warn_dup() and sysfs wrappers around kernfs interfaces.
The respective declarations in fs/sysfs/sysfs.h are moved to
fs/kernfs/kernfs-internal.h.
This is pure relocation.
v2: sysfs_symlink_target_lock was mistakenly relocated to kernfs. It
should remain with sysfs. Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo
Greg Kroah-Hartman
Родитель
ffed24e228
Коммит
fd7b9f7b97
988
fs/kernfs/dir.c
988
fs/kernfs/dir.c
|
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@ -7,3 +7,991 @@
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include <linux/idr.h>
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#include <linux/slab.h>
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#include <linux/security.h>
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#include <linux/hash.h>
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#include "kernfs-internal.h"
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DEFINE_MUTEX(sysfs_mutex);
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#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb)
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static DEFINE_SPINLOCK(sysfs_ino_lock);
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static DEFINE_IDA(sysfs_ino_ida);
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/**
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* sysfs_name_hash
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* @name: Null terminated string to hash
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* @ns: Namespace tag to hash
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*
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* Returns 31 bit hash of ns + name (so it fits in an off_t )
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*/
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static unsigned int sysfs_name_hash(const char *name, const void *ns)
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{
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unsigned long hash = init_name_hash();
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unsigned int len = strlen(name);
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while (len--)
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hash = partial_name_hash(*name++, hash);
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hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31));
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hash &= 0x7fffffffU;
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/* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */
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if (hash < 1)
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hash += 2;
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if (hash >= INT_MAX)
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hash = INT_MAX - 1;
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return hash;
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}
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static int sysfs_name_compare(unsigned int hash, const char *name,
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const void *ns, const struct sysfs_dirent *sd)
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{
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if (hash != sd->s_hash)
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return hash - sd->s_hash;
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if (ns != sd->s_ns)
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return ns - sd->s_ns;
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return strcmp(name, sd->s_name);
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}
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static int sysfs_sd_compare(const struct sysfs_dirent *left,
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const struct sysfs_dirent *right)
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{
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return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns,
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right);
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}
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/**
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* sysfs_link_sibling - link sysfs_dirent into sibling rbtree
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* @sd: sysfs_dirent of interest
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*
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* Link @sd into its sibling rbtree which starts from
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* sd->s_parent->s_dir.children.
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*
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* Locking:
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* mutex_lock(sysfs_mutex)
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*
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* RETURNS:
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* 0 on susccess -EEXIST on failure.
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*/
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static int sysfs_link_sibling(struct sysfs_dirent *sd)
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{
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struct rb_node **node = &sd->s_parent->s_dir.children.rb_node;
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struct rb_node *parent = NULL;
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if (sysfs_type(sd) == SYSFS_DIR)
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sd->s_parent->s_dir.subdirs++;
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while (*node) {
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struct sysfs_dirent *pos;
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int result;
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pos = to_sysfs_dirent(*node);
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parent = *node;
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result = sysfs_sd_compare(sd, pos);
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if (result < 0)
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node = &pos->s_rb.rb_left;
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else if (result > 0)
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node = &pos->s_rb.rb_right;
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else
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return -EEXIST;
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}
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/* add new node and rebalance the tree */
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rb_link_node(&sd->s_rb, parent, node);
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rb_insert_color(&sd->s_rb, &sd->s_parent->s_dir.children);
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return 0;
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}
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/**
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* sysfs_unlink_sibling - unlink sysfs_dirent from sibling rbtree
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* @sd: sysfs_dirent of interest
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*
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* Unlink @sd from its sibling rbtree which starts from
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* sd->s_parent->s_dir.children.
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*
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* Locking:
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* mutex_lock(sysfs_mutex)
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*/
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static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
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{
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if (sysfs_type(sd) == SYSFS_DIR)
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sd->s_parent->s_dir.subdirs--;
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rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
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}
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/**
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* sysfs_get_active - get an active reference to sysfs_dirent
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* @sd: sysfs_dirent to get an active reference to
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*
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* Get an active reference of @sd. This function is noop if @sd
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* is NULL.
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*
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* RETURNS:
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* Pointer to @sd on success, NULL on failure.
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*/
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struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
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{
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if (unlikely(!sd))
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return NULL;
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if (!atomic_inc_unless_negative(&sd->s_active))
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return NULL;
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if (sd->s_flags & SYSFS_FLAG_LOCKDEP)
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rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
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return sd;
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}
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/**
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* sysfs_put_active - put an active reference to sysfs_dirent
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* @sd: sysfs_dirent to put an active reference to
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*
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* Put an active reference to @sd. This function is noop if @sd
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* is NULL.
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*/
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void sysfs_put_active(struct sysfs_dirent *sd)
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{
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int v;
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if (unlikely(!sd))
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return;
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if (sd->s_flags & SYSFS_FLAG_LOCKDEP)
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rwsem_release(&sd->dep_map, 1, _RET_IP_);
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v = atomic_dec_return(&sd->s_active);
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if (likely(v != SD_DEACTIVATED_BIAS))
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return;
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/* atomic_dec_return() is a mb(), we'll always see the updated
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* sd->u.completion.
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*/
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complete(sd->u.completion);
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}
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/**
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* sysfs_deactivate - deactivate sysfs_dirent
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* @sd: sysfs_dirent to deactivate
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*
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* Deny new active references and drain existing ones.
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*/
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static void sysfs_deactivate(struct sysfs_dirent *sd)
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{
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DECLARE_COMPLETION_ONSTACK(wait);
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int v;
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BUG_ON(!(sd->s_flags & SYSFS_FLAG_REMOVED));
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if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF))
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return;
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sd->u.completion = (void *)&wait;
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rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
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/* atomic_add_return() is a mb(), put_active() will always see
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* the updated sd->u.completion.
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*/
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v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
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if (v != SD_DEACTIVATED_BIAS) {
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lock_contended(&sd->dep_map, _RET_IP_);
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wait_for_completion(&wait);
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}
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lock_acquired(&sd->dep_map, _RET_IP_);
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rwsem_release(&sd->dep_map, 1, _RET_IP_);
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}
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static int sysfs_alloc_ino(unsigned int *pino)
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{
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int ino, rc;
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retry:
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spin_lock(&sysfs_ino_lock);
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rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
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spin_unlock(&sysfs_ino_lock);
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if (rc == -EAGAIN) {
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if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
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goto retry;
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rc = -ENOMEM;
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}
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*pino = ino;
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return rc;
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}
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static void sysfs_free_ino(unsigned int ino)
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{
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spin_lock(&sysfs_ino_lock);
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ida_remove(&sysfs_ino_ida, ino);
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spin_unlock(&sysfs_ino_lock);
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}
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/**
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* kernfs_get - get a reference count on a sysfs_dirent
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* @sd: the target sysfs_dirent
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*/
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void kernfs_get(struct sysfs_dirent *sd)
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{
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if (sd) {
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WARN_ON(!atomic_read(&sd->s_count));
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atomic_inc(&sd->s_count);
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}
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}
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EXPORT_SYMBOL_GPL(kernfs_get);
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/**
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* kernfs_put - put a reference count on a sysfs_dirent
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* @sd: the target sysfs_dirent
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*
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* Put a reference count of @sd and destroy it if it reached zero.
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*/
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void kernfs_put(struct sysfs_dirent *sd)
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{
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struct sysfs_dirent *parent_sd;
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if (!sd || !atomic_dec_and_test(&sd->s_count))
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return;
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repeat:
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/* Moving/renaming is always done while holding reference.
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* sd->s_parent won't change beneath us.
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*/
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parent_sd = sd->s_parent;
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WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED),
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"sysfs: free using entry: %s/%s\n",
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parent_sd ? parent_sd->s_name : "", sd->s_name);
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if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
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kernfs_put(sd->s_symlink.target_sd);
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if (sysfs_type(sd) & SYSFS_COPY_NAME)
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kfree(sd->s_name);
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if (sd->s_iattr && sd->s_iattr->ia_secdata)
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security_release_secctx(sd->s_iattr->ia_secdata,
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sd->s_iattr->ia_secdata_len);
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kfree(sd->s_iattr);
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sysfs_free_ino(sd->s_ino);
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kmem_cache_free(sysfs_dir_cachep, sd);
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sd = parent_sd;
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if (sd && atomic_dec_and_test(&sd->s_count))
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goto repeat;
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}
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EXPORT_SYMBOL_GPL(kernfs_put);
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static int sysfs_dentry_delete(const struct dentry *dentry)
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{
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struct sysfs_dirent *sd = dentry->d_fsdata;
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return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED));
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}
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static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
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{
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struct sysfs_dirent *sd;
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if (flags & LOOKUP_RCU)
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return -ECHILD;
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sd = dentry->d_fsdata;
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mutex_lock(&sysfs_mutex);
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/* The sysfs dirent has been deleted */
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if (sd->s_flags & SYSFS_FLAG_REMOVED)
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goto out_bad;
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/* The sysfs dirent has been moved? */
|
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if (dentry->d_parent->d_fsdata != sd->s_parent)
|
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goto out_bad;
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||||
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||||
/* The sysfs dirent has been renamed */
|
||||
if (strcmp(dentry->d_name.name, sd->s_name) != 0)
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||||
goto out_bad;
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||||
|
||||
/* The sysfs dirent has been moved to a different namespace */
|
||||
if (sd->s_parent && (sd->s_parent->s_flags & SYSFS_FLAG_NS) &&
|
||||
sysfs_info(dentry->d_sb)->ns != sd->s_ns)
|
||||
goto out_bad;
|
||||
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
out_valid:
|
||||
return 1;
|
||||
out_bad:
|
||||
/* Remove the dentry from the dcache hashes.
|
||||
* If this is a deleted dentry we use d_drop instead of d_delete
|
||||
* so sysfs doesn't need to cope with negative dentries.
|
||||
*
|
||||
* If this is a dentry that has simply been renamed we
|
||||
* use d_drop to remove it from the dcache lookup on its
|
||||
* old parent. If this dentry persists later when a lookup
|
||||
* is performed at its new name the dentry will be readded
|
||||
* to the dcache hashes.
|
||||
*/
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
|
||||
/* If we have submounts we must allow the vfs caches
|
||||
* to lie about the state of the filesystem to prevent
|
||||
* leaks and other nasty things.
|
||||
*/
|
||||
if (check_submounts_and_drop(dentry) != 0)
|
||||
goto out_valid;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void sysfs_dentry_release(struct dentry *dentry)
|
||||
{
|
||||
kernfs_put(dentry->d_fsdata);
|
||||
}
|
||||
|
||||
const struct dentry_operations sysfs_dentry_ops = {
|
||||
.d_revalidate = sysfs_dentry_revalidate,
|
||||
.d_delete = sysfs_dentry_delete,
|
||||
.d_release = sysfs_dentry_release,
|
||||
};
|
||||
|
||||
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
|
||||
{
|
||||
char *dup_name = NULL;
|
||||
struct sysfs_dirent *sd;
|
||||
|
||||
if (type & SYSFS_COPY_NAME) {
|
||||
name = dup_name = kstrdup(name, GFP_KERNEL);
|
||||
if (!name)
|
||||
return NULL;
|
||||
}
|
||||
|
||||
sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
|
||||
if (!sd)
|
||||
goto err_out1;
|
||||
|
||||
if (sysfs_alloc_ino(&sd->s_ino))
|
||||
goto err_out2;
|
||||
|
||||
atomic_set(&sd->s_count, 1);
|
||||
atomic_set(&sd->s_active, 0);
|
||||
|
||||
sd->s_name = name;
|
||||
sd->s_mode = mode;
|
||||
sd->s_flags = type | SYSFS_FLAG_REMOVED;
|
||||
|
||||
return sd;
|
||||
|
||||
err_out2:
|
||||
kmem_cache_free(sysfs_dir_cachep, sd);
|
||||
err_out1:
|
||||
kfree(dup_name);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/**
|
||||
* sysfs_addrm_start - prepare for sysfs_dirent add/remove
|
||||
* @acxt: pointer to sysfs_addrm_cxt to be used
|
||||
*
|
||||
* This function is called when the caller is about to add or remove
|
||||
* sysfs_dirent. This function acquires sysfs_mutex. @acxt is used
|
||||
* to keep and pass context to other addrm functions.
|
||||
*
|
||||
* LOCKING:
|
||||
* Kernel thread context (may sleep). sysfs_mutex is locked on
|
||||
* return.
|
||||
*/
|
||||
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt)
|
||||
__acquires(sysfs_mutex)
|
||||
{
|
||||
memset(acxt, 0, sizeof(*acxt));
|
||||
|
||||
mutex_lock(&sysfs_mutex);
|
||||
}
|
||||
|
||||
/**
|
||||
* sysfs_add_one - add sysfs_dirent to parent without warning
|
||||
* @acxt: addrm context to use
|
||||
* @sd: sysfs_dirent to be added
|
||||
* @parent_sd: the parent sysfs_dirent to add @sd to
|
||||
*
|
||||
* Get @parent_sd and set @sd->s_parent to it and increment nlink of
|
||||
* the 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,
|
||||
struct sysfs_dirent *parent_sd)
|
||||
{
|
||||
bool has_ns = parent_sd->s_flags & SYSFS_FLAG_NS;
|
||||
struct sysfs_inode_attrs *ps_iattr;
|
||||
int ret;
|
||||
|
||||
if (has_ns != (bool)sd->s_ns) {
|
||||
WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
|
||||
has_ns ? "required" : "invalid",
|
||||
parent_sd->s_name, sd->s_name);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (sysfs_type(parent_sd) != SYSFS_DIR)
|
||||
return -EINVAL;
|
||||
|
||||
sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
|
||||
sd->s_parent = parent_sd;
|
||||
kernfs_get(parent_sd);
|
||||
|
||||
ret = sysfs_link_sibling(sd);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
/* Update timestamps on the parent */
|
||||
ps_iattr = parent_sd->s_iattr;
|
||||
if (ps_iattr) {
|
||||
struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
|
||||
ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
|
||||
}
|
||||
|
||||
/* Mark the entry added into directory tree */
|
||||
sd->s_flags &= ~SYSFS_FLAG_REMOVED;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* 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 unlinked from the children list.
|
||||
*
|
||||
* 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().
|
||||
*/
|
||||
static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt,
|
||||
struct sysfs_dirent *sd)
|
||||
{
|
||||
struct sysfs_inode_attrs *ps_iattr;
|
||||
|
||||
/*
|
||||
* Removal can be called multiple times on the same node. Only the
|
||||
* first invocation is effective and puts the base ref.
|
||||
*/
|
||||
if (sd->s_flags & SYSFS_FLAG_REMOVED)
|
||||
return;
|
||||
|
||||
sysfs_unlink_sibling(sd);
|
||||
|
||||
/* Update timestamps on the parent */
|
||||
ps_iattr = sd->s_parent->s_iattr;
|
||||
if (ps_iattr) {
|
||||
struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
|
||||
ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
|
||||
}
|
||||
|
||||
sd->s_flags |= SYSFS_FLAG_REMOVED;
|
||||
sd->u.removed_list = acxt->removed;
|
||||
acxt->removed = sd;
|
||||
}
|
||||
|
||||
/**
|
||||
* sysfs_addrm_finish - finish up sysfs_dirent add/remove
|
||||
* @acxt: addrm context to finish up
|
||||
*
|
||||
* Finish up sysfs_dirent add/remove. Resources acquired by
|
||||
* sysfs_addrm_start() are released and removed sysfs_dirents are
|
||||
* cleaned up.
|
||||
*
|
||||
* LOCKING:
|
||||
* sysfs_mutex is released.
|
||||
*/
|
||||
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
|
||||
__releases(sysfs_mutex)
|
||||
{
|
||||
/* release resources acquired by sysfs_addrm_start() */
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
|
||||
/* kill removed sysfs_dirents */
|
||||
while (acxt->removed) {
|
||||
struct sysfs_dirent *sd = acxt->removed;
|
||||
|
||||
acxt->removed = sd->u.removed_list;
|
||||
|
||||
sysfs_deactivate(sd);
|
||||
sysfs_unmap_bin_file(sd);
|
||||
kernfs_put(sd);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* kernfs_find_ns - find sysfs_dirent with the given name
|
||||
* @parent: sysfs_dirent to search under
|
||||
* @name: name to look for
|
||||
* @ns: the namespace tag to use
|
||||
*
|
||||
* Look for sysfs_dirent with name @name under @parent. Returns pointer to
|
||||
* the found sysfs_dirent on success, %NULL on failure.
|
||||
*/
|
||||
static struct sysfs_dirent *kernfs_find_ns(struct sysfs_dirent *parent,
|
||||
const unsigned char *name,
|
||||
const void *ns)
|
||||
{
|
||||
struct rb_node *node = parent->s_dir.children.rb_node;
|
||||
bool has_ns = parent->s_flags & SYSFS_FLAG_NS;
|
||||
unsigned int hash;
|
||||
|
||||
lockdep_assert_held(&sysfs_mutex);
|
||||
|
||||
if (has_ns != (bool)ns) {
|
||||
WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
|
||||
has_ns ? "required" : "invalid",
|
||||
parent->s_name, name);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
hash = sysfs_name_hash(name, ns);
|
||||
while (node) {
|
||||
struct sysfs_dirent *sd;
|
||||
int result;
|
||||
|
||||
sd = to_sysfs_dirent(node);
|
||||
result = sysfs_name_compare(hash, name, ns, sd);
|
||||
if (result < 0)
|
||||
node = node->rb_left;
|
||||
else if (result > 0)
|
||||
node = node->rb_right;
|
||||
else
|
||||
return sd;
|
||||
}
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/**
|
||||
* kernfs_find_and_get_ns - find and get sysfs_dirent with the given name
|
||||
* @parent: sysfs_dirent to search under
|
||||
* @name: name to look for
|
||||
* @ns: the namespace tag to use
|
||||
*
|
||||
* Look for sysfs_dirent with name @name under @parent and get a reference
|
||||
* if found. This function may sleep and returns pointer to the found
|
||||
* sysfs_dirent on success, %NULL on failure.
|
||||
*/
|
||||
struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
|
||||
const char *name, const void *ns)
|
||||
{
|
||||
struct sysfs_dirent *sd;
|
||||
|
||||
mutex_lock(&sysfs_mutex);
|
||||
sd = kernfs_find_ns(parent, name, ns);
|
||||
kernfs_get(sd);
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
|
||||
return sd;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns);
|
||||
|
||||
/**
|
||||
* kernfs_create_dir_ns - create a directory
|
||||
* @parent: parent in which to create a new directory
|
||||
* @name: name of the new directory
|
||||
* @priv: opaque data associated with the new directory
|
||||
* @ns: optional namespace tag of the directory
|
||||
*
|
||||
* Returns the created node on success, ERR_PTR() value on failure.
|
||||
*/
|
||||
struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
|
||||
const char *name, void *priv,
|
||||
const void *ns)
|
||||
{
|
||||
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 ERR_PTR(-ENOMEM);
|
||||
|
||||
sd->s_ns = ns;
|
||||
sd->priv = priv;
|
||||
|
||||
/* link in */
|
||||
sysfs_addrm_start(&acxt);
|
||||
rc = sysfs_add_one(&acxt, sd, parent);
|
||||
sysfs_addrm_finish(&acxt);
|
||||
|
||||
if (!rc)
|
||||
return sd;
|
||||
|
||||
kernfs_put(sd);
|
||||
return ERR_PTR(rc);
|
||||
}
|
||||
|
||||
static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
|
||||
unsigned int flags)
|
||||
{
|
||||
struct dentry *ret = NULL;
|
||||
struct dentry *parent = dentry->d_parent;
|
||||
struct sysfs_dirent *parent_sd = parent->d_fsdata;
|
||||
struct sysfs_dirent *sd;
|
||||
struct inode *inode;
|
||||
const void *ns = NULL;
|
||||
|
||||
mutex_lock(&sysfs_mutex);
|
||||
|
||||
if (parent_sd->s_flags & SYSFS_FLAG_NS)
|
||||
ns = sysfs_info(dir->i_sb)->ns;
|
||||
|
||||
sd = kernfs_find_ns(parent_sd, dentry->d_name.name, ns);
|
||||
|
||||
/* no such entry */
|
||||
if (!sd) {
|
||||
ret = ERR_PTR(-ENOENT);
|
||||
goto out_unlock;
|
||||
}
|
||||
kernfs_get(sd);
|
||||
dentry->d_fsdata = sd;
|
||||
|
||||
/* attach dentry and inode */
|
||||
inode = sysfs_get_inode(dir->i_sb, sd);
|
||||
if (!inode) {
|
||||
ret = ERR_PTR(-ENOMEM);
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
/* instantiate and hash dentry */
|
||||
ret = d_materialise_unique(dentry, inode);
|
||||
out_unlock:
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
const struct inode_operations sysfs_dir_inode_operations = {
|
||||
.lookup = sysfs_lookup,
|
||||
.permission = sysfs_permission,
|
||||
.setattr = sysfs_setattr,
|
||||
.getattr = sysfs_getattr,
|
||||
.setxattr = sysfs_setxattr,
|
||||
};
|
||||
|
||||
static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos)
|
||||
{
|
||||
struct sysfs_dirent *last;
|
||||
|
||||
while (true) {
|
||||
struct rb_node *rbn;
|
||||
|
||||
last = pos;
|
||||
|
||||
if (sysfs_type(pos) != SYSFS_DIR)
|
||||
break;
|
||||
|
||||
rbn = rb_first(&pos->s_dir.children);
|
||||
if (!rbn)
|
||||
break;
|
||||
|
||||
pos = to_sysfs_dirent(rbn);
|
||||
}
|
||||
|
||||
return last;
|
||||
}
|
||||
|
||||
/**
|
||||
* sysfs_next_descendant_post - find the next descendant for post-order walk
|
||||
* @pos: the current position (%NULL to initiate traversal)
|
||||
* @root: sysfs_dirent whose descendants to walk
|
||||
*
|
||||
* Find the next descendant to visit for post-order traversal of @root's
|
||||
* descendants. @root is included in the iteration and the last node to be
|
||||
* visited.
|
||||
*/
|
||||
static struct sysfs_dirent *sysfs_next_descendant_post(struct sysfs_dirent *pos,
|
||||
struct sysfs_dirent *root)
|
||||
{
|
||||
struct rb_node *rbn;
|
||||
|
||||
lockdep_assert_held(&sysfs_mutex);
|
||||
|
||||
/* if first iteration, visit leftmost descendant which may be root */
|
||||
if (!pos)
|
||||
return sysfs_leftmost_descendant(root);
|
||||
|
||||
/* if we visited @root, we're done */
|
||||
if (pos == root)
|
||||
return NULL;
|
||||
|
||||
/* if there's an unvisited sibling, visit its leftmost descendant */
|
||||
rbn = rb_next(&pos->s_rb);
|
||||
if (rbn)
|
||||
return sysfs_leftmost_descendant(to_sysfs_dirent(rbn));
|
||||
|
||||
/* no sibling left, visit parent */
|
||||
return pos->s_parent;
|
||||
}
|
||||
|
||||
static void __kernfs_remove(struct sysfs_addrm_cxt *acxt,
|
||||
struct sysfs_dirent *sd)
|
||||
{
|
||||
struct sysfs_dirent *pos, *next;
|
||||
|
||||
if (!sd)
|
||||
return;
|
||||
|
||||
pr_debug("sysfs %s: removing\n", sd->s_name);
|
||||
|
||||
next = NULL;
|
||||
do {
|
||||
pos = next;
|
||||
next = sysfs_next_descendant_post(pos, sd);
|
||||
if (pos)
|
||||
sysfs_remove_one(acxt, pos);
|
||||
} while (next);
|
||||
}
|
||||
|
||||
/**
|
||||
* kernfs_remove - remove a sysfs_dirent recursively
|
||||
* @sd: the sysfs_dirent to remove
|
||||
*
|
||||
* Remove @sd along with all its subdirectories and files.
|
||||
*/
|
||||
void kernfs_remove(struct sysfs_dirent *sd)
|
||||
{
|
||||
struct sysfs_addrm_cxt acxt;
|
||||
|
||||
sysfs_addrm_start(&acxt);
|
||||
__kernfs_remove(&acxt, sd);
|
||||
sysfs_addrm_finish(&acxt);
|
||||
}
|
||||
|
||||
/**
|
||||
* kernfs_remove_by_name_ns - find a sysfs_dirent by name and remove it
|
||||
* @dir_sd: parent of the target
|
||||
* @name: name of the sysfs_dirent to remove
|
||||
* @ns: namespace tag of the sysfs_dirent to remove
|
||||
*
|
||||
* Look for the sysfs_dirent with @name and @ns under @dir_sd and remove
|
||||
* it. Returns 0 on success, -ENOENT if such entry doesn't exist.
|
||||
*/
|
||||
int kernfs_remove_by_name_ns(struct sysfs_dirent *dir_sd, const char *name,
|
||||
const void *ns)
|
||||
{
|
||||
struct sysfs_addrm_cxt acxt;
|
||||
struct sysfs_dirent *sd;
|
||||
|
||||
if (!dir_sd) {
|
||||
WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n",
|
||||
name);
|
||||
return -ENOENT;
|
||||
}
|
||||
|
||||
sysfs_addrm_start(&acxt);
|
||||
|
||||
sd = kernfs_find_ns(dir_sd, name, ns);
|
||||
if (sd)
|
||||
__kernfs_remove(&acxt, sd);
|
||||
|
||||
sysfs_addrm_finish(&acxt);
|
||||
|
||||
if (sd)
|
||||
return 0;
|
||||
else
|
||||
return -ENOENT;
|
||||
}
|
||||
|
||||
/**
|
||||
* kernfs_rename_ns - move and rename a kernfs_node
|
||||
* @sd: target node
|
||||
* @new_parent: new parent to put @sd under
|
||||
* @new_name: new name
|
||||
* @new_ns: new namespace tag
|
||||
*/
|
||||
int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent,
|
||||
const char *new_name, const void *new_ns)
|
||||
{
|
||||
int error;
|
||||
|
||||
mutex_lock(&sysfs_mutex);
|
||||
|
||||
error = 0;
|
||||
if ((sd->s_parent == new_parent) && (sd->s_ns == new_ns) &&
|
||||
(strcmp(sd->s_name, new_name) == 0))
|
||||
goto out; /* nothing to rename */
|
||||
|
||||
error = -EEXIST;
|
||||
if (kernfs_find_ns(new_parent, new_name, new_ns))
|
||||
goto out;
|
||||
|
||||
/* rename sysfs_dirent */
|
||||
if (strcmp(sd->s_name, new_name) != 0) {
|
||||
error = -ENOMEM;
|
||||
new_name = kstrdup(new_name, GFP_KERNEL);
|
||||
if (!new_name)
|
||||
goto out;
|
||||
|
||||
kfree(sd->s_name);
|
||||
sd->s_name = new_name;
|
||||
}
|
||||
|
||||
/*
|
||||
* Move to the appropriate place in the appropriate directories rbtree.
|
||||
*/
|
||||
sysfs_unlink_sibling(sd);
|
||||
kernfs_get(new_parent);
|
||||
kernfs_put(sd->s_parent);
|
||||
sd->s_ns = new_ns;
|
||||
sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
|
||||
sd->s_parent = new_parent;
|
||||
sysfs_link_sibling(sd);
|
||||
|
||||
error = 0;
|
||||
out:
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
return error;
|
||||
}
|
||||
|
||||
/**
|
||||
* kernfs_enable_ns - enable namespace under a directory
|
||||
* @sd: directory of interest, should be empty
|
||||
*
|
||||
* This is to be called right after @sd is created to enable namespace
|
||||
* under it. All children of @sd must have non-NULL namespace tags and
|
||||
* only the ones which match the super_block's tag will be visible.
|
||||
*/
|
||||
void kernfs_enable_ns(struct sysfs_dirent *sd)
|
||||
{
|
||||
WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR);
|
||||
WARN_ON_ONCE(!RB_EMPTY_ROOT(&sd->s_dir.children));
|
||||
sd->s_flags |= SYSFS_FLAG_NS;
|
||||
}
|
||||
|
||||
/* Relationship between s_mode and the DT_xxx types */
|
||||
static inline unsigned char dt_type(struct sysfs_dirent *sd)
|
||||
{
|
||||
return (sd->s_mode >> 12) & 15;
|
||||
}
|
||||
|
||||
static int sysfs_dir_release(struct inode *inode, struct file *filp)
|
||||
{
|
||||
kernfs_put(filp->private_data);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct sysfs_dirent *sysfs_dir_pos(const void *ns,
|
||||
struct sysfs_dirent *parent_sd, loff_t hash, struct sysfs_dirent *pos)
|
||||
{
|
||||
if (pos) {
|
||||
int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) &&
|
||||
pos->s_parent == parent_sd &&
|
||||
hash == pos->s_hash;
|
||||
kernfs_put(pos);
|
||||
if (!valid)
|
||||
pos = NULL;
|
||||
}
|
||||
if (!pos && (hash > 1) && (hash < INT_MAX)) {
|
||||
struct rb_node *node = parent_sd->s_dir.children.rb_node;
|
||||
while (node) {
|
||||
pos = to_sysfs_dirent(node);
|
||||
|
||||
if (hash < pos->s_hash)
|
||||
node = node->rb_left;
|
||||
else if (hash > pos->s_hash)
|
||||
node = node->rb_right;
|
||||
else
|
||||
break;
|
||||
}
|
||||
}
|
||||
/* Skip over entries in the wrong namespace */
|
||||
while (pos && pos->s_ns != ns) {
|
||||
struct rb_node *node = rb_next(&pos->s_rb);
|
||||
if (!node)
|
||||
pos = NULL;
|
||||
else
|
||||
pos = to_sysfs_dirent(node);
|
||||
}
|
||||
return pos;
|
||||
}
|
||||
|
||||
static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns,
|
||||
struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos)
|
||||
{
|
||||
pos = sysfs_dir_pos(ns, parent_sd, ino, pos);
|
||||
if (pos)
|
||||
do {
|
||||
struct rb_node *node = rb_next(&pos->s_rb);
|
||||
if (!node)
|
||||
pos = NULL;
|
||||
else
|
||||
pos = to_sysfs_dirent(node);
|
||||
} while (pos && pos->s_ns != ns);
|
||||
return pos;
|
||||
}
|
||||
|
||||
static int sysfs_readdir(struct file *file, struct dir_context *ctx)
|
||||
{
|
||||
struct dentry *dentry = file->f_path.dentry;
|
||||
struct sysfs_dirent *parent_sd = dentry->d_fsdata;
|
||||
struct sysfs_dirent *pos = file->private_data;
|
||||
const void *ns = NULL;
|
||||
|
||||
if (!dir_emit_dots(file, ctx))
|
||||
return 0;
|
||||
mutex_lock(&sysfs_mutex);
|
||||
|
||||
if (parent_sd->s_flags & SYSFS_FLAG_NS)
|
||||
ns = sysfs_info(dentry->d_sb)->ns;
|
||||
|
||||
for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos);
|
||||
pos;
|
||||
pos = sysfs_dir_next_pos(ns, parent_sd, ctx->pos, pos)) {
|
||||
const char *name = pos->s_name;
|
||||
unsigned int type = dt_type(pos);
|
||||
int len = strlen(name);
|
||||
ino_t ino = pos->s_ino;
|
||||
|
||||
ctx->pos = pos->s_hash;
|
||||
file->private_data = pos;
|
||||
kernfs_get(pos);
|
||||
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
if (!dir_emit(ctx, name, len, ino, type))
|
||||
return 0;
|
||||
mutex_lock(&sysfs_mutex);
|
||||
}
|
||||
mutex_unlock(&sysfs_mutex);
|
||||
file->private_data = NULL;
|
||||
ctx->pos = INT_MAX;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
|
||||
{
|
||||
struct inode *inode = file_inode(file);
|
||||
loff_t ret;
|
||||
|
||||
mutex_lock(&inode->i_mutex);
|
||||
ret = generic_file_llseek(file, offset, whence);
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
const struct file_operations sysfs_dir_operations = {
|
||||
.read = generic_read_dir,
|
||||
.iterate = sysfs_readdir,
|
||||
.release = sysfs_dir_release,
|
||||
.llseek = sysfs_dir_llseek,
|
||||
};
|
||||
|
|
|
|||
|
|
@ -14,6 +14,7 @@
|
|||
#include <linux/lockdep.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/rbtree.h>
|
||||
#include <linux/mutex.h>
|
||||
|
||||
#include <linux/kernfs.h>
|
||||
|
||||
|
|
@ -125,4 +126,20 @@ int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
|
|||
size_t size, int flags);
|
||||
int sysfs_inode_init(void);
|
||||
|
||||
/*
|
||||
* dir.c
|
||||
*/
|
||||
extern struct mutex sysfs_mutex;
|
||||
extern const struct dentry_operations sysfs_dentry_ops;
|
||||
extern const struct file_operations sysfs_dir_operations;
|
||||
extern const struct inode_operations sysfs_dir_inode_operations;
|
||||
|
||||
struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
|
||||
void sysfs_put_active(struct sysfs_dirent *sd);
|
||||
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt);
|
||||
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
|
||||
struct sysfs_dirent *parent_sd);
|
||||
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
|
||||
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
|
||||
|
||||
#endif /* __KERNFS_INTERNAL_H */
|
||||
|
|
|
|||
986
fs/sysfs/dir.c
986
fs/sysfs/dir.c
Разница между файлами не показана из-за своего большого размера
Загрузить разницу
|
|
@ -34,22 +34,9 @@ extern struct kmem_cache *sysfs_dir_cachep;
|
|||
/*
|
||||
* dir.c
|
||||
*/
|
||||
extern struct mutex sysfs_mutex;
|
||||
extern spinlock_t sysfs_symlink_target_lock;
|
||||
extern const struct dentry_operations sysfs_dentry_ops;
|
||||
|
||||
extern const struct file_operations sysfs_dir_operations;
|
||||
extern const struct inode_operations sysfs_dir_inode_operations;
|
||||
|
||||
struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
|
||||
void sysfs_put_active(struct sysfs_dirent *sd);
|
||||
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt);
|
||||
void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name);
|
||||
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
|
||||
struct sysfs_dirent *parent_sd);
|
||||
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
|
||||
|
||||
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);
|
||||
|
||||
/*
|
||||
* file.c
|
||||
|
|
|
|||
Загрузка…
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