diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/bin.c | 36 | ||||
| -rw-r--r-- | fs/sysfs/dir.c | 759 | ||||
| -rw-r--r-- | fs/sysfs/file.c | 248 | ||||
| -rw-r--r-- | fs/sysfs/group.c | 2 | ||||
| -rw-r--r-- | fs/sysfs/inode.c | 106 | ||||
| -rw-r--r-- | fs/sysfs/mount.c | 30 | ||||
| -rw-r--r-- | fs/sysfs/symlink.c | 34 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 185 |
8 files changed, 598 insertions, 802 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 5afe2a26f5d..006fc64227d 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -1,9 +1,15 @@ /* - * bin.c - binary file operations for sysfs. + * fs/sysfs/bin.c - sysfs binary file implementation * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Matthew Wilcox * Copyright (c) 2004 Silicon Graphics, Inc. + * 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 @@ -14,9 +20,9 @@ #include <linux/kobject.h> #include <linux/module.h> #include <linux/slab.h> +#include <linux/mutex.h> #include <asm/uaccess.h> -#include <asm/semaphore.h> #include "sysfs.h" @@ -30,8 +36,8 @@ static int fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) { struct sysfs_dirent *attr_sd = dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; + struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; int rc; /* need attr_sd for attr, its parent for kobj */ @@ -87,8 +93,8 @@ static int flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) { struct sysfs_dirent *attr_sd = dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; + struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; int rc; /* need attr_sd for attr, its parent for kobj */ @@ -140,8 +146,8 @@ static int mmap(struct file *file, struct vm_area_struct *vma) { struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; + struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; int rc; mutex_lock(&bb->mutex); @@ -167,12 +173,12 @@ static int mmap(struct file *file, struct vm_area_struct *vma) static int open(struct inode * inode, struct file * file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr; + struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; struct bin_buffer *bb = NULL; int error; - /* need attr_sd for attr */ - if (!sysfs_get_active(attr_sd)) + /* binary file operations requires both @sd and its parent */ + if (!sysfs_get_active_two(attr_sd)) return -ENODEV; error = -EACCES; @@ -193,13 +199,12 @@ static int open(struct inode * inode, struct file * file) mutex_init(&bb->mutex); file->private_data = bb; - /* open succeeded, put active reference and pin attr_sd */ - sysfs_put_active(attr_sd); - sysfs_get(attr_sd); + /* open succeeded, put active references */ + sysfs_put_active_two(attr_sd); return 0; err_out: - sysfs_put_active(attr_sd); + sysfs_put_active_two(attr_sd); kfree(bb); return error; } @@ -211,7 +216,6 @@ static int release(struct inode * inode, struct file * file) if (bb->mmapped) sysfs_put_active_two(attr_sd); - sysfs_put(attr_sd); kfree(bb->buffer); kfree(bb); return 0; diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 83e76b3813c..7a8ce9e98b3 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 @@ -11,13 +19,14 @@ #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); -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); /** @@ -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 +87,38 @@ 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, - strlen(cur->s_name)); - dput(parent_dentry); - - if (IS_ERR(dentry)) { - sysfs_put(cur); - return dentry; - } + 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); - 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 +281,7 @@ 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 +297,7 @@ 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 +325,6 @@ 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 +339,6 @@ 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 +402,8 @@ 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 +411,30 @@ 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 +443,7 @@ 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 +454,9 @@ 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 +475,49 @@ 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; + + inode = ilookup(sysfs_sb, sd->s_ino); + if (!inode) + return; - /* We're not holding a reference to ->s_dentry dentry but the - * field will stay valid as long as sysfs_assoc_lock is held. + /* 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 +530,8 @@ 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 +557,6 @@ int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) sysfs_deactivate(sd); sysfs_put(sd); } - - return acxt->cnt; } /** @@ -651,8 +577,8 @@ 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 +616,25 @@ 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 +646,18 @@ 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 +665,20 @@ 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 +688,11 @@ 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 +709,6 @@ 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 +729,13 @@ 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 +763,68 @@ 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 +836,69 @@ 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 +909,51 @@ 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, }; diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 3e1cc062a74..d3be1e7fb48 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -1,15 +1,22 @@ /* - * file.c - operations for regular (text) files. + * fs/sysfs/file.c - sysfs regular (text) file 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. */ #include <linux/module.h> -#include <linux/fsnotify.h> #include <linux/kobject.h> #include <linux/namei.h> #include <linux/poll.h> #include <linux/list.h> +#include <linux/mutex.h> #include <asm/uaccess.h> -#include <asm/semaphore.h> #include "sysfs.h" @@ -50,14 +57,33 @@ static struct sysfs_ops subsys_sysfs_ops = { .store = subsys_attr_store, }; +/* + * There's one sysfs_buffer for each open file and one + * sysfs_open_dirent for each sysfs_dirent with one or more open + * files. + * + * filp->private_data points to sysfs_buffer and + * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open + * is protected by sysfs_open_dirent_lock. + */ +static spinlock_t sysfs_open_dirent_lock = SPIN_LOCK_UNLOCKED; + +struct sysfs_open_dirent { + atomic_t refcnt; + atomic_t event; + wait_queue_head_t poll; + struct list_head buffers; /* goes through sysfs_buffer.list */ +}; + struct sysfs_buffer { size_t count; loff_t pos; char * page; struct sysfs_ops * ops; - struct semaphore sem; + struct mutex mutex; int needs_read_fill; int event; + struct list_head list; }; /** @@ -74,7 +100,7 @@ struct sysfs_buffer { static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer) { struct sysfs_dirent *attr_sd = dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; struct sysfs_ops * ops = buffer->ops; int ret = 0; ssize_t count; @@ -88,8 +114,8 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer if (!sysfs_get_active_two(attr_sd)) return -ENODEV; - buffer->event = atomic_read(&attr_sd->s_event); - count = ops->show(kobj, attr_sd->s_elem.attr.attr, buffer->page); + buffer->event = atomic_read(&attr_sd->s_attr.open->event); + count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page); sysfs_put_active_two(attr_sd); @@ -128,7 +154,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) struct sysfs_buffer * buffer = file->private_data; ssize_t retval = 0; - down(&buffer->sem); + mutex_lock(&buffer->mutex); if (buffer->needs_read_fill) { retval = fill_read_buffer(file->f_path.dentry,buffer); if (retval) @@ -139,7 +165,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) retval = simple_read_from_buffer(buf, count, ppos, buffer->page, buffer->count); out: - up(&buffer->sem); + mutex_unlock(&buffer->mutex); return retval; } @@ -189,7 +215,7 @@ static int flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count) { struct sysfs_dirent *attr_sd = dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; struct sysfs_ops * ops = buffer->ops; int rc; @@ -197,7 +223,7 @@ flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t if (!sysfs_get_active_two(attr_sd)) return -ENODEV; - rc = ops->store(kobj, attr_sd->s_elem.attr.attr, buffer->page, count); + rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count); sysfs_put_active_two(attr_sd); @@ -228,20 +254,102 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t struct sysfs_buffer * buffer = file->private_data; ssize_t len; - down(&buffer->sem); + mutex_lock(&buffer->mutex); len = fill_write_buffer(buffer, buf, count); if (len > 0) len = flush_write_buffer(file->f_path.dentry, buffer, len); if (len > 0) *ppos += len; - up(&buffer->sem); + mutex_unlock(&buffer->mutex); return len; } +/** + * sysfs_get_open_dirent - get or create sysfs_open_dirent + * @sd: target sysfs_dirent + * @buffer: sysfs_buffer for this instance of open + * + * If @sd->s_attr.open exists, increment its reference count; + * otherwise, create one. @buffer is chained to the buffers + * list. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * 0 on success, -errno on failure. + */ +static int sysfs_get_open_dirent(struct sysfs_dirent *sd, + struct sysfs_buffer *buffer) +{ + struct sysfs_open_dirent *od, *new_od = NULL; + + retry: + spin_lock(&sysfs_open_dirent_lock); + + if (!sd->s_attr.open && new_od) { + sd->s_attr.open = new_od; + new_od = NULL; + } + + od = sd->s_attr.open; + if (od) { + atomic_inc(&od->refcnt); + list_add_tail(&buffer->list, &od->buffers); + } + + spin_unlock(&sysfs_open_dirent_lock); + + if (od) { + kfree(new_od); + return 0; + } + + /* not there, initialize a new one and retry */ + new_od = kmalloc(sizeof(*new_od), GFP_KERNEL); + if (!new_od) + return -ENOMEM; + + atomic_set(&new_od->refcnt, 0); + atomic_set(&new_od->event, 1); + init_waitqueue_head(&new_od->poll); + INIT_LIST_HEAD(&new_od->buffers); + goto retry; +} + +/** + * sysfs_put_open_dirent - put sysfs_open_dirent + * @sd: target sysfs_dirent + * @buffer: associated sysfs_buffer + * + * Put @sd->s_attr.open and unlink @buffer from the buffers list. + * If reference count reaches zero, disassociate and free it. + * + * LOCKING: + * None. + */ +static void sysfs_put_open_dirent(struct sysfs_dirent *sd, + struct sysfs_buffer *buffer) +{ + struct sysfs_open_dirent *od = sd->s_attr.open; + + spin_lock(&sysfs_open_dirent_lock); + + list_del(&buffer->list); + if (atomic_dec_and_test(&od->refcnt)) + sd->s_attr.open = NULL; + else + od = NULL; + + spin_unlock(&sysfs_open_dirent_lock); + + kfree(od); +} + static int sysfs_open_file(struct inode *inode, struct file *file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; struct sysfs_buffer * buffer; struct sysfs_ops * ops = NULL; int error; @@ -294,33 +402,38 @@ static int sysfs_open_file(struct inode *inode, struct file *file) if (!buffer) goto err_out; - init_MUTEX(&buffer->sem); + mutex_init(&buffer->mutex); buffer->needs_read_fill = 1; buffer->ops = ops; file->private_data = buffer; - /* open succeeded, put active references and pin attr_sd */ + /* make sure we have open dirent struct */ + error = sysfs_get_open_dirent(attr_sd, buffer); + if (error) + goto err_free; + + /* open succeeded, put active references */ sysfs_put_active_two(attr_sd); - sysfs_get(attr_sd); return 0; + err_free: + kfree(buffer); err_out: sysfs_put_active_two(attr_sd); return error; } -static int sysfs_release(struct inode * inode, struct file * filp) +static int sysfs_release(struct inode *inode, struct file *filp) { - struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; + struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata; struct sysfs_buffer *buffer = filp->private_data; - sysfs_put(attr_sd); + sysfs_put_open_dirent(sd, buffer); + + if (buffer->page) + free_page((unsigned long)buffer->page); + kfree(buffer); - if (buffer) { - if (buffer->page) - free_page((unsigned long)buffer->page); - kfree(buffer); - } return 0; } @@ -335,24 +448,24 @@ static int sysfs_release(struct inode * inode, struct file * filp) * again will not get new data, or reset the state of 'poll'. * Reminder: this only works for attributes which actively support * it, and it is not possible to test an attribute from userspace - * to see if it supports poll (Nether 'poll' or 'select' return + * to see if it supports poll (Neither 'poll' nor 'select' return * an appropriate error code). When in doubt, set a suitable timeout value. */ static unsigned int sysfs_poll(struct file *filp, poll_table *wait) { struct sysfs_buffer * buffer = filp->private_data; struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj; + struct sysfs_open_dirent *od = attr_sd->s_attr.open; /* need parent for the kobj, grab both */ if (!sysfs_get_active_two(attr_sd)) goto trigger; - poll_wait(filp, &kobj->poll, wait); + poll_wait(filp, &od->poll, wait); sysfs_put_active_two(attr_sd); - if (buffer->event != atomic_read(&attr_sd->s_event)) + if (buffer->event != atomic_read(&od->event)) goto trigger; return 0; @@ -373,8 +486,17 @@ void sysfs_notify(struct kobject *k, char *dir, char *attr) if (sd && attr) sd = sysfs_find_dirent(sd, attr); if (sd) { - atomic_inc(&sd->s_event); - wake_up_interruptible(&k->poll); + struct sysfs_open_dirent *od; + + spin_lock(&sysfs_open_dirent_lock); + + od = sd->s_attr.open; + if (od) { + atomic_inc(&od->event); + wake_up_interruptible(&od->poll); + } + + spin_unlock(&sysfs_open_dirent_lock); } mutex_unlock(&sysfs_mutex); @@ -397,25 +519,21 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; + int rc; sd = sysfs_new_dirent(attr->name, mode, type); if (!sd) return -ENOMEM; - sd->s_elem.attr.attr = (void *)attr; + sd->s_attr.attr = (void *)attr; sysfs_addrm_start(&acxt, dir_sd); + rc = sysfs_add_one(&acxt, sd); + sysfs_addrm_finish(&acxt); - if (!sysfs_find_dirent(dir_sd, attr->name)) { - sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } - - if (!sysfs_addrm_finish(&acxt)) { + if (rc) sysfs_put(sd); - return -EEXIST; - } - return 0; + return rc; } @@ -457,42 +575,6 @@ int sysfs_add_file_to_group(struct kobject *kobj, } EXPORT_SYMBOL_GPL(sysfs_add_file_to_group); - -/** - * sysfs_update_file - update the modified timestamp on an object attribute. - * @kobj: object we're acting for. - * @attr: attribute descriptor. - */ -int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) -{ - struct sysfs_dirent *victim_sd = NULL; - struct dentry *victim = NULL; - int rc; - - rc = -ENOENT; - victim_sd = sysfs_get_dirent(kobj->sd, attr->name); - if (!victim_sd) - goto out; - - victim = sysfs_get_dentry(victim_sd); - if (IS_ERR(victim)) { - rc = PTR_ERR(victim); - victim = NULL; - goto out; - } - - mutex_lock(&victim->d_inode->i_mutex); - victim->d_inode->i_mtime = CURRENT_TIME; - fsnotify_modify(victim); - mutex_unlock(&victim->d_inode->i_mutex); - rc = 0; - out: - dput(victim); - sysfs_put(victim_sd); - return rc; -} - - /** * sysfs_chmod_file - update the modified mode value on an object attribute. * @kobj: object we're acting for. @@ -513,7 +595,9 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) if (!victim_sd) goto out; + mutex_lock(&sysfs_rename_mutex); victim = sysfs_get_dentry(victim_sd); + mutex_unlock(&sysfs_rename_mutex); if (IS_ERR(victim)) { rc = PTR_ERR(victim); victim = NULL; @@ -521,10 +605,19 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) } inode = victim->d_inode; + mutex_lock(&inode->i_mutex); + newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; rc = notify_change(victim, &newattrs); + + if (rc == 0) { + mutex_lock(&sysfs_mutex); + victim_sd->s_mode = newattrs.ia_mode; + mutex_unlock(&sysfs_mutex); + } + mutex_unlock(&inode->i_mutex); out: dput(victim); @@ -632,4 +725,3 @@ EXPORT_SYMBOL_GPL(sysfs_schedule_callback); EXPORT_SYMBOL_GPL(sysfs_create_file); EXPORT_SYMBOL_GPL(sysfs_remove_file); -EXPORT_SYMBOL_GPL(sysfs_update_file); diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index f318b73c790..d1972374655 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -13,8 +13,6 @@ #include <linux/dcache.h> #include <linux/namei.h> #include <linux/err.h> -#include <linux/fs.h> -#include <asm/semaphore.h> #include "sysfs.h" diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 10d1b52899f..d9262f74f94 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -1,7 +1,11 @@ /* - * inode.c - basic inode and dentry operations. + * fs/sysfs/inode.c - basic sysfs inode and dentry operations * - * sysfs is Copyright (c) 2001-3 Patrick Mochel + * 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. */ @@ -14,15 +18,14 @@ #include <linux/capability.h> #include <linux/errno.h> #include <linux/sched.h> -#include <asm/semaphore.h> #include "sysfs.h" extern struct super_block * sysfs_sb; static const struct address_space_operations sysfs_aops = { .readpage = simple_readpage, - .prepare_write = simple_prepare_write, - .commit_write = simple_commit_write + .write_begin = simple_write_begin, + .write_end = simple_write_end, }; static struct backing_dev_info sysfs_backing_dev_info = { @@ -34,14 +37,9 @@ static const struct inode_operations sysfs_inode_operations ={ .setattr = sysfs_setattr, }; -void sysfs_delete_inode(struct inode *inode) +int __init sysfs_inode_init(void) { - /* Free the shadowed directory inode operations */ - if (sysfs_is_shadowed_inode(inode)) { - kfree(inode->i_op); - inode->i_op = NULL; - } - return generic_delete_inode(inode); + return bdi_init(&sysfs_backing_dev_info); } int sysfs_setattr(struct dentry * dentry, struct iattr * iattr) @@ -133,8 +131,22 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) */ static struct lock_class_key sysfs_inode_imutex_key; +static int sysfs_count_nlink(struct sysfs_dirent *sd) +{ + struct sysfs_dirent *child; + int nr = 0; + + for (child = sd->s_dir.children; child; child = child->s_sibling) + if (sysfs_type(child) == SYSFS_DIR) + nr++; + + return nr + 2; +} + static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) { + struct bin_attribute *bin_attr; + inode->i_blocks = 0; inode->i_mapping->a_ops = &sysfs_aops; inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; @@ -150,6 +162,32 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) set_inode_attr(inode, sd->s_iattr); } else set_default_inode_attr(inode, sd->s_mode); + + + /* 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_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(); + } + + unlock_new_inode(inode); } /** @@ -177,50 +215,24 @@ struct inode * sysfs_get_inode(struct sysfs_dirent *sd) return inode; } -/** - * sysfs_instantiate - instantiate dentry - * @dentry: dentry to be instantiated - * @inode: inode associated with @sd - * - * Unlock @inode if locked and instantiate @dentry with @inode. - * - * LOCKING: - * None. - */ -void sysfs_instantiate(struct dentry *dentry, struct inode *inode) -{ - BUG_ON(!dentry || dentry->d_inode); - - if (inode->i_state & I_NEW) - unlock_new_inode(inode); - - d_instantiate(dentry, inode); -} - int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name) { struct sysfs_addrm_cxt acxt; - struct sysfs_dirent **pos, *sd; + struct sysfs_dirent *sd; if (!dir_sd) return -ENOENT; sysfs_addrm_start(&acxt, dir_sd); - for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) { - sd = *pos; - - if (!sysfs_type(sd)) - continue; - if (!strcmp(sd->s_name, name)) { - *pos = sd->s_sibling; - sd->s_sibling = NULL; - sysfs_remove_one(&acxt, sd); - break; - } - } + sd = sysfs_find_dirent(dir_sd, name); + if (sd) + sysfs_remove_one(&acxt, sd); + + sysfs_addrm_finish(&acxt); - if (sysfs_addrm_finish(&acxt)) + if (sd) return 0; - return -ENOENT; + else + return -ENOENT; } diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index fbc7b65fe26..74168266cd5 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -1,5 +1,13 @@ /* - * mount.c - operations for initializing and mounting sysfs. + * fs/sysfs/symlink.c - operations for initializing and mounting sysfs + * + * 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. */ #define DEBUG @@ -8,25 +16,25 @@ #include <linux/mount.h> #include <linux/pagemap.h> #include <linux/init.h> -#include <asm/semaphore.h> #include "sysfs.h" /* Random magic number */ #define SYSFS_MAGIC 0x62656572 -struct vfsmount *sysfs_mount; +static struct vfsmount *sysfs_mount; struct super_block * sysfs_sb = NULL; struct kmem_cache *sysfs_dir_cachep; static const struct super_operations sysfs_ops = { .statfs = simple_statfs, - .drop_inode = sysfs_delete_inode, + .drop_inode = generic_delete_inode, }; struct sysfs_dirent sysfs_root = { + .s_name = "", .s_count = ATOMIC_INIT(1), - .s_flags = SYSFS_ROOT, + .s_flags = SYSFS_DIR, .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, .s_ino = 1, }; @@ -50,11 +58,6 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent) return -ENOMEM; } - inode->i_op = &sysfs_dir_inode_operations; - inode->i_fop = &sysfs_dir_operations; - inc_nlink(inode); /* directory, account for "." */ - unlock_new_inode(inode); - /* instantiate and link root dentry */ root = d_alloc_root(inode); if (!root) { @@ -62,7 +65,6 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent) iput(inode); return -ENOMEM; } - sysfs_root.s_dentry = root; root->d_fsdata = &sysfs_root; sb->s_root = root; return 0; @@ -77,7 +79,7 @@ static int sysfs_get_sb(struct file_system_type *fs_type, static struct file_system_type sysfs_fs_type = { .name = "sysfs", .get_sb = sysfs_get_sb, - .kill_sb = kill_litter_super, + .kill_sb = kill_anon_super, }; int __init sysfs_init(void) @@ -90,6 +92,10 @@ int __init sysfs_init(void) if (!sysfs_dir_cachep) goto out; + err = sysfs_inode_init(); + if (err) + goto out_err; + err = register_filesystem(&sysfs_fs_type); if (!err) { sysfs_mount = kern_mount(&sysfs_fs_type); diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 4ce687f0b5d..3eac20c63c4 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -1,5 +1,13 @@ /* - * symlink.c - operations for sysfs symlinks. + * fs/sysfs/symlink.c - sysfs symlink 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. */ #include <linux/fs.h> @@ -7,7 +15,7 @@ #include <linux/module.h> #include <linux/kobject.h> #include <linux/namei.h> -#include <asm/semaphore.h> +#include <linux/mutex.h> #include "sysfs.h" @@ -60,10 +68,9 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char BUG_ON(!name); - if (!kobj) { - if (sysfs_mount && sysfs_mount->mnt_sb) - parent_sd = sysfs_mount->mnt_sb->s_root->d_fsdata; - } else + if (!kobj) + parent_sd = &sysfs_root; + else parent_sd = kobj->sd; error = -EFAULT; @@ -87,20 +94,15 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char if (!sd) goto out_put; - sd->s_elem.symlink.target_sd = target_sd; + sd->s_symlink.target_sd = target_sd; target_sd = NULL; /* reference is now owned by the symlink */ sysfs_addrm_start(&acxt, parent_sd); + error = 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)) { - error = -EEXIST; + if (error) goto out_put; - } return 0; @@ -148,7 +150,7 @@ static int sysfs_getlink(struct dentry *dentry, char * path) { struct sysfs_dirent *sd = dentry->d_fsdata; struct sysfs_dirent *parent_sd = sd->s_parent; - struct sysfs_dirent *target_sd = sd->s_elem.symlink.target_sd; + struct sysfs_dirent *target_sd = sd->s_symlink.target_sd; int error; mutex_lock(&sysfs_mutex); diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 6b8c8d76d30..f8417988f6b 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -1,20 +1,39 @@ +/* + * fs/sysfs/sysfs.h - sysfs internal header file + * + * 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. + */ + +struct sysfs_open_dirent; + +/* type-specific structures for sysfs_dirent->s_* union members */ struct sysfs_elem_dir { - struct kobject * kobj; + struct kobject *kobj; + /* children list starts here and goes through sd->s_sibling */ + struct sysfs_dirent *children; }; struct sysfs_elem_symlink { - struct sysfs_dirent * target_sd; + struct sysfs_dirent *target_sd; }; struct sysfs_elem_attr { - struct attribute * attr; + struct attribute *attr; + struct sysfs_open_dirent *open; }; struct sysfs_elem_bin_attr { - struct bin_attribute * bin_attr; + struct bin_attribute *bin_attr; }; /* + * sysfs_dirent - the building block of sysfs hierarchy. Each and + * every sysfs node is represented by single sysfs_dirent. + * * As long as s_count reference is held, the sysfs_dirent itself is * accessible. Dereferencing s_elem or any other outer entity * requires s_active reference. @@ -22,28 +41,43 @@ struct sysfs_elem_bin_attr { struct sysfs_dirent { atomic_t s_count; atomic_t s_active; - struct sysfs_dirent * s_parent; - struct sysfs_dirent * s_sibling; - struct sysfs_dirent * s_children; - const char * s_name; + struct sysfs_dirent *s_parent; + struct sysfs_dirent *s_sibling; + const char *s_name; union { - struct sysfs_elem_dir dir; - struct sysfs_elem_symlink symlink; - struct sysfs_elem_attr attr; - struct sysfs_elem_bin_attr bin_attr; - } s_elem; + struct sysfs_elem_dir s_dir; + struct sysfs_elem_symlink s_symlink; + struct sysfs_elem_attr s_attr; + struct sysfs_elem_bin_attr s_bin_attr; + }; unsigned int s_flags; - umode_t s_mode; ino_t s_ino; - struct dentry * s_dentry; - struct iattr * s_iattr; - atomic_t s_event; + umode_t s_mode; + struct iattr *s_iattr; }; -#define SD_DEACTIVATED_BIAS INT_MIN +#define SD_DEACTIVATED_BIAS INT_MIN + +#define SYSFS_TYPE_MASK 0x00ff +#define SYSFS_DIR 0x0001 +#define SYSFS_KOBJ_ATTR 0x0002 +#define SYSFS_KOBJ_BIN_ATTR 0x0004 +#define SYSFS_KOBJ_LINK 0x0008 +#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK) + +#define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK +#define SYSFS_FLAG_REMOVED 0x0200 + +static inline unsigned int sysfs_type(struct sysfs_dirent *sd) +{ + return sd->s_flags & SYSFS_TYPE_MASK; +} +/* + * Context structure to be used while adding/removing nodes. + */ struct sysfs_addrm_cxt { struct sysfs_dirent *parent_sd; struct inode *parent_inode; @@ -51,63 +85,47 @@ struct sysfs_addrm_cxt { int cnt; }; -extern struct vfsmount * sysfs_mount; +/* + * mount.c + */ extern struct sysfs_dirent sysfs_root; +extern struct super_block *sysfs_sb; extern struct kmem_cache *sysfs_dir_cachep; -extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd); -extern void sysfs_link_sibling(struct sysfs_dirent *sd); -extern void sysfs_unlink_sibling(struct sysfs_dirent *sd); -extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); -extern void sysfs_put_active(struct sysfs_dirent *sd); -extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd); -extern void sysfs_put_active_two(struct sysfs_dirent *sd); -extern void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *parent_sd); -extern void sysfs_add_one(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *sd); -extern void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, - struct sysfs_dirent *sd); -extern int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); - -extern void sysfs_delete_inode(struct inode *inode); -extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd); -extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode); - -extern void release_sysfs_dirent(struct sysfs_dirent * sd); -extern struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, - const unsigned char *name); -extern struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, - const unsigned char *name); -extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, - int type); - -extern int sysfs_add_file(struct sysfs_dirent *dir_sd, - const struct attribute *attr, int type); -extern int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name); -extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name); - -extern int sysfs_create_subdir(struct kobject *kobj, const char *name, - struct sysfs_dirent **p_sd); -extern void sysfs_remove_subdir(struct sysfs_dirent *sd); - -extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); - -extern spinlock_t sysfs_assoc_lock; +/* + * dir.c + */ extern struct mutex sysfs_mutex; -extern struct super_block * sysfs_sb; +extern struct mutex sysfs_rename_mutex; +extern spinlock_t sysfs_assoc_lock; + extern const struct file_operations sysfs_dir_operations; -extern const struct file_operations sysfs_file_operations; -extern const struct file_operations bin_fops; extern const struct inode_operations sysfs_dir_inode_operations; -extern const struct inode_operations sysfs_symlink_inode_operations; - -static inline unsigned int sysfs_type(struct sysfs_dirent *sd) -{ - return sd->s_flags & SYSFS_TYPE_MASK; -} -static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd) +struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd); +struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); +void sysfs_put_active(struct sysfs_dirent *sd); +struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd); +void sysfs_put_active_two(struct sysfs_dirent *sd); +void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, + struct sysfs_dirent *parent_sd); +int 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); +void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); + +struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name); +struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, + const unsigned char *name); +struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); + +void release_sysfs_dirent(struct sysfs_dirent *sd); + +int sysfs_create_subdir(struct kobject *kobj, const char *name, + struct sysfs_dirent **p_sd); +void sysfs_remove_subdir(struct sysfs_dirent *sd); + +static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd) { if (sd) { WARN_ON(!atomic_read(&sd->s_count)); @@ -116,13 +134,34 @@ static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd) return sd; } -static inline void sysfs_put(struct sysfs_dirent * sd) +static inline void sysfs_put(struct sysfs_dirent *sd) { if (sd && atomic_dec_and_test(&sd->s_count)) release_sysfs_dirent(sd); } -static inline int sysfs_is_shadowed_inode(struct inode *inode) -{ - return S_ISDIR(inode->i_mode) && inode->i_op->follow_link; -} +/* + * inode.c + */ +struct inode *sysfs_get_inode(struct sysfs_dirent *sd); +int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); +int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name); +int sysfs_inode_init(void); + +/* + * file.c + */ +extern const struct file_operations sysfs_file_operations; + +int sysfs_add_file(struct sysfs_dirent *dir_sd, + const struct attribute *attr, int type); + +/* + * bin.c + */ +extern const struct file_operations bin_fops; + +/* + * symlink.c + */ +extern const struct inode_operations sysfs_symlink_inode_operations; |