diff options
Diffstat (limited to 'fs/sysfs/dir.c')
| -rw-r--r-- | fs/sysfs/dir.c | 754 |
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, }; |
