From 90bc61359de0148f8627073d68a22edc7ed9893d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 31 Jul 2007 19:15:08 +0900 Subject: sysfs: Remove first pass at shadow directory support While shadow directories appear to be a good idea, the current scheme of controlling their creation and destruction outside of sysfs appears to be a locking and maintenance nightmare in the face of sysfs directories dynamically coming and going. Which can now occur for directories containing network devices when CONFIG_SYSFS_DEPRECATED is not set. This patch removes everything from the initial shadow directory support that allowed the shadow directory creation to be controlled at a higher level. So except for a few bits of sysfs_rename_dir everything from commit b592fcfe7f06c15ec11774b5be7ce0de3aa86e73 is now gone. Signed-off-by: Eric W. Biederman Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/sysfs.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 6b8c8d76d30..b55e510ea23 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -70,7 +70,6 @@ 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); @@ -121,8 +120,3 @@ 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; -} -- cgit v1.2.3-70-g09d2 From 41fc1c27452e041a18e5141b8203ee0ea72bc483 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Aug 2007 21:38:03 +0900 Subject: sysfs: make sysfs_add/remove_one() call link/unlink_sibling() implictly When adding or removing a sysfs_dirent, the user used to be required to call link/unlink separately. It was for two reasons - code looked like that before sysfs_addrm_cxt conversion and to avoid looping through parent_sd->children list twice during removal. Performance optimization during removal just isn't worth it. Make sysfs_add/remove_one() call sysfs_link/unlink_sibing() implicitly. This makes code simpler albeit slightly less efficient. This change doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 21 ++++++++++----------- fs/sysfs/file.c | 4 +--- fs/sysfs/inode.c | 17 ++++------------- fs/sysfs/symlink.c | 4 +--- fs/sysfs/sysfs.h | 2 -- 5 files changed, 16 insertions(+), 32 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 9504d4cb63e..354675ad096 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -30,7 +30,7 @@ static DEFINE_IDA(sysfs_ino_ida); * 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; @@ -49,7 +49,7 @@ void sysfs_link_sibling(struct sysfs_dirent *sd) * 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; @@ -500,6 +500,8 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) inc_nlink(acxt->parent_inode); acxt->cnt++; + + sysfs_link_sibling(sd); } /** @@ -521,7 +523,9 @@ 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; @@ -697,10 +701,8 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, /* link in */ sysfs_addrm_start(&acxt, parent_sd); - if (!sysfs_find_dirent(parent_sd, name)) { + if (!sysfs_find_dirent(parent_sd, name)) sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } if (!sysfs_addrm_finish(&acxt)) { sysfs_put(sd); @@ -821,7 +823,6 @@ 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); } @@ -846,11 +847,9 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) 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_type(sd) != SYSFS_DIR) sysfs_remove_one(&acxt, sd); - } else + else pos = &(*pos)->s_sibling; } sysfs_addrm_finish(&acxt); diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index b21d11b4675..ea0e494d7d5 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -405,10 +405,8 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, sysfs_addrm_start(&acxt, dir_sd); - if (!sysfs_find_dirent(dir_sd, attr->name)) { + if (!sysfs_find_dirent(dir_sd, attr->name)) sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } if (!sysfs_addrm_finish(&acxt)) { sysfs_put(sd); diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 45128b79bc6..efb4062fe09 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -189,25 +189,16 @@ void sysfs_instantiate(struct dentry *dentry, struct inode *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); if (sysfs_addrm_finish(&acxt)) return 0; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 90484533801..c129f307936 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -92,10 +92,8 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char sysfs_addrm_start(&acxt, parent_sd); - if (!sysfs_find_dirent(parent_sd, name)) { + if (!sysfs_find_dirent(parent_sd, name)) sysfs_add_one(&acxt, sd); - sysfs_link_sibling(sd); - } if (!sysfs_addrm_finish(&acxt)) { error = -EEXIST; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index b55e510ea23..32b8b64e5cf 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -56,8 +56,6 @@ extern struct sysfs_dirent sysfs_root; 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); -- cgit v1.2.3-70-g09d2 From 23dc279950a056c33a14d09cf759f5173d41abd9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Aug 2007 21:38:03 +0900 Subject: sysfs: make sysfs_add_one() automatically check for duplicate entry Make sysfs_add_one() check for duplicate entry and return -EEXIST if such entry exists. This simplifies node addition code a bit. This patch doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 26 +++++++++++++++++--------- fs/sysfs/file.c | 12 +++++------- fs/sysfs/symlink.c | 9 +++------ fs/sysfs/sysfs.h | 2 +- 4 files changed, 26 insertions(+), 23 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 354675ad096..620603296c6 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -491,9 +491,16 @@ 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)) + return -EEXIST; + sd->s_parent = sysfs_get(acxt->parent_sd); if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) @@ -502,6 +509,8 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) acxt->cnt++; sysfs_link_sibling(sd); + + return 0; } /** @@ -691,6 +700,7 @@ 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); @@ -700,17 +710,15 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, /* 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); - - 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, diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index ea0e494d7d5..33bb3406dc4 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -397,6 +397,7 @@ 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) @@ -404,16 +405,13 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, sd->s_elem.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); - - if (!sysfs_addrm_finish(&acxt)) { + if (rc) sysfs_put(sd); - return -EEXIST; - } - return 0; + return rc; } diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index c129f307936..a6b13f12b0e 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -91,14 +91,11 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char 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); - - if (!sysfs_addrm_finish(&acxt)) { - error = -EEXIST; + if (error) goto out_put; - } return 0; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 32b8b64e5cf..bb3f0c999b1 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -62,7 +62,7 @@ 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, +extern int 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); -- cgit v1.2.3-70-g09d2 From 990e53f880be9ff93072b4cce590ec2826cee0b6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 2 Aug 2007 21:38:03 +0900 Subject: sysfs: make sysfs_addrm_finish() return void With the previous sysfs_add_one() update, there is only one user of the return value of sysfs_addrm_finish() and the user can switch to testing @sd easily. Make sysfs_addrm_finish() return void for cleaner semantics as suggested by Satyam Sharma. This patch doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo Cc: Satyam Sharma Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 7 +------ fs/sysfs/inode.c | 7 +++++-- fs/sysfs/sysfs.h | 2 +- 3 files changed, 7 insertions(+), 9 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 620603296c6..a0da2b05a75 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -609,11 +609,8 @@ 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); @@ -639,8 +636,6 @@ int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) sysfs_deactivate(sd); sysfs_put(sd); } - - return acxt->cnt; } /** diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index efb4062fe09..e22db6cd4df 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -200,7 +200,10 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name) if (sd) sysfs_remove_one(&acxt, sd); - if (sysfs_addrm_finish(&acxt)) + sysfs_addrm_finish(&acxt); + + if (sd) return 0; - return -ENOENT; + else + return -ENOENT; } diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index bb3f0c999b1..04367547103 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -66,7 +66,7 @@ extern int 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_addrm_finish(struct sysfs_addrm_cxt *acxt); extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd); extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode); -- cgit v1.2.3-70-g09d2 From 119dd52be33dfe6285f586ab7354897fdefc7e23 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 20 Aug 2007 21:36:29 +0900 Subject: sysfs: Remove sysfs_instantiate Now that sysfs_get_inode is dropping the inode lock we no longer have a need from sysfs_instantiate. Signed-off-by: Eric W. Biederman Signed-off-by: Tejun Heo Cc: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 2 +- fs/sysfs/inode.c | 17 ----------------- fs/sysfs/sysfs.h | 1 - 3 files changed, 1 insertion(+), 19 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 5a70a93fc2f..739dda176b4 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -773,7 +773,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, goto out_unlock; } - sysfs_instantiate(dentry, inode); + d_instantiate(dentry, inode); sysfs_attach_dentry(sd, dentry); out_unlock: diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 200e1bf6f93..0d706a86d2c 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -211,23 +211,6 @@ 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); - - d_instantiate(dentry, inode); -} - int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name) { struct sysfs_addrm_cxt acxt; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 04367547103..8a0aea1ab86 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -69,7 +69,6 @@ extern void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, extern void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); 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, -- cgit v1.2.3-70-g09d2 From 7d0c7d676cc066413e1583b5af9fba8011972d41 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 20 Aug 2007 21:36:30 +0900 Subject: sysfs: Make sysfs_mount static This patch modifies the users of sysfs_mount to use sysfs_root instead (which is what they are looking for). It then makes sysfs_mount static to keep people from using it by accident. The net result is slightly faster and cleaner code. Signed-off-by: Eric W. Biederman Signed-off-by: Tejun Heo Cc: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 4 +--- fs/sysfs/mount.c | 2 +- fs/sysfs/symlink.c | 7 +++---- fs/sysfs/sysfs.h | 1 - 4 files changed, 5 insertions(+), 9 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 739dda176b4..7f4abe17670 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -737,10 +737,8 @@ int sysfs_create_dir(struct kobject * kobj) 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) diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index ac7625631fc..8989cbb51a3 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -14,7 +14,7 @@ /* 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; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index a6b13f12b0e..8ad38bccc0e 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -60,10 +60,9 @@ 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; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 8a0aea1ab86..77253aabc4a 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -51,7 +51,6 @@ struct sysfs_addrm_cxt { int cnt; }; -extern struct vfsmount * sysfs_mount; extern struct sysfs_dirent sysfs_root; extern struct kmem_cache *sysfs_dir_cachep; -- cgit v1.2.3-70-g09d2 From 932ea2e374dd1ca26676297a5eccd1cdab86f7cd Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 20 Aug 2007 21:36:30 +0900 Subject: sysfs: Introduce sysfs_rename_mutex Looking carefully at the rename code we have a subtle dependency that the structure of sysfs not change while we are performing a rename. If the parent directory of the object we are renaming changes while the rename is being performed nasty things could happen when we go to release our locks. So introduce a sysfs_rename_mutex to prevent this highly unlikely theoretical issue. In addition hold sysfs_rename_mutex over all calls to sysfs_get_dentry. Allowing sysfs_get_dentry to be simplified in the future. Signed-off-by: Eric W. Biederman Signed-off-by: Tejun Heo Cc: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 8 +++++++- fs/sysfs/file.c | 4 ++++ fs/sysfs/sysfs.h | 1 + 3 files changed, 12 insertions(+), 1 deletion(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 1af963e66e3..9fe83d23dc2 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -15,6 +15,7 @@ #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; @@ -82,7 +83,7 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd) * down from there 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. @@ -858,6 +859,8 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name) const char *dup_name = NULL; int error; + mutex_lock(&sysfs_rename_mutex); + /* get the original dentry */ sd = kobj->sd; old_dentry = sysfs_get_dentry(sd); @@ -915,6 +918,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name) kfree(dup_name); dput(old_dentry); dput(new_dentry); + mutex_unlock(&sysfs_rename_mutex); return error; } @@ -926,6 +930,7 @@ 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; @@ -982,6 +987,7 @@ again: dput(new_parent); dput(old_dentry); dput(new_dentry); + mutex_unlock(&sysfs_rename_mutex); return error; } diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 16f39c30b09..ff93c92164b 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -470,7 +470,9 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) 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; @@ -509,7 +511,9 @@ 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; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 77253aabc4a..179e6a26ece 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -90,6 +90,7 @@ extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); extern spinlock_t sysfs_assoc_lock; extern struct mutex sysfs_mutex; +extern struct mutex sysfs_rename_mutex; extern struct super_block * sysfs_sb; extern const struct file_operations sysfs_dir_operations; extern const struct file_operations sysfs_file_operations; -- cgit v1.2.3-70-g09d2 From 5a26b79c426f8e55ebf7204cb138eb6b1645d4d3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 20 Aug 2007 21:36:30 +0900 Subject: sysfs: Remove s_dentry The only uses of s_dentry left are the code that maintains s_dentry and trivial users that don't actually need it. So this patch removes the s_dentry maintenance code and restructures the trivial uses to use something else. Signed-off-by: Eric W. Biederman Signed-off-by: Tejun Heo Cc: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 32 ++++---------------------------- fs/sysfs/mount.c | 1 - fs/sysfs/sysfs.h | 1 - 3 files changed, 4 insertions(+), 30 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 1c3dc5d01cc..36b6c796d4d 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -289,22 +289,7 @@ 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); } @@ -352,9 +337,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) * @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) */ @@ -362,12 +344,6 @@ 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); } @@ -846,7 +822,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name) /* rename */ d_add(new_dentry, NULL); - d_move(sd->s_dentry, new_dentry); + d_move(old_dentry, new_dentry); error = 0; goto out_unlock; @@ -881,7 +857,7 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) error = PTR_ERR(old_dentry); goto out_dput; } - 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)) { @@ -907,7 +883,7 @@ again: } else 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. */ diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 8989cbb51a3..28bf359981f 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -56,7 +56,6 @@ 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; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 179e6a26ece..791b3ed91a9 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -37,7 +37,6 @@ struct sysfs_dirent { unsigned int s_flags; umode_t s_mode; ino_t s_ino; - struct dentry * s_dentry; struct iattr * s_iattr; atomic_t s_event; }; -- cgit v1.2.3-70-g09d2 From 59f69015684b3de7b9472be9a81b1a978f93a496 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:10 +0900 Subject: sysfs: clean up header files sysfs is about to go through major overhaul making this a pretty good opportunity to clean up (out-of-tree changes and pending patches will need regeneration anyway). Clean up headers. * Kill space between * and symbolname. * Move SYSFS_* type constants and flags into fs/sysfs/sysfs.h. They're internal to sysfs. * Reformat function prototypes and add argument symbol names. * Make dummy function definition order match that of function prototypes. * Add some comments. * Reorganize fs/sysfs/sysfs.h according to which file the declared variable or feature lives in. This patch does not introduce any behavior change. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/sysfs.h | 148 +++++++++++++++++++++++++++++++------------------- include/linux/sysfs.h | 127 +++++++++++++++++++------------------------ 2 files changed, 149 insertions(+), 126 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 791b3ed91a9..63adbecc9ba 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -1,20 +1,24 @@ +/* type-specific structures for sysfs_dirent->s_* union members */ struct sysfs_elem_dir { - struct kobject * kobj; + struct kobject *kobj; }; 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_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. @@ -22,10 +26,10 @@ 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; + struct sysfs_dirent *s_children; + const char *s_name; union { struct sysfs_elem_dir dir; @@ -37,12 +41,31 @@ struct sysfs_dirent { unsigned int s_flags; umode_t s_mode; ino_t s_ino; - struct iattr * s_iattr; + struct iattr *s_iattr; atomic_t s_event; }; -#define SD_DEACTIVATED_BIAS INT_MIN +#define SD_DEACTIVATED_BIAS INT_MIN +#define SYSFS_TYPE_MASK 0x00ff +#define SYSFS_ROOT 0x0001 +#define SYSFS_DIR 0x0002 +#define SYSFS_KOBJ_ATTR 0x0004 +#define SYSFS_KOBJ_BIN_ATTR 0x0008 +#define SYSFS_KOBJ_LINK 0x0020 +#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; @@ -50,59 +73,47 @@ struct sysfs_addrm_cxt { int cnt; }; +/* + * 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 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 int 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 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); - -extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd); - -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 mutex sysfs_rename_mutex; -extern struct super_block * sysfs_sb; +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)); @@ -111,8 +122,33 @@ 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); } + +/* + * 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); + +/* + * 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; diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index c16e4c51162..b393bb44962 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -23,14 +23,14 @@ struct module; * until the tree gets cleaned up fully. */ struct attribute { - const char * name; - struct module * owner; + const char *name; + struct module *owner; mode_t mode; }; struct attribute_group { - const char * name; - struct attribute ** attrs; + const char *name; + struct attribute **attrs; }; @@ -74,65 +74,43 @@ struct sysfs_ops { ssize_t (*store)(struct kobject *,struct attribute *,const char *, size_t); }; -#define SYSFS_TYPE_MASK 0x00ff -#define SYSFS_ROOT 0x0001 -#define SYSFS_DIR 0x0002 -#define SYSFS_KOBJ_ATTR 0x0004 -#define SYSFS_KOBJ_BIN_ATTR 0x0008 -#define SYSFS_KOBJ_LINK 0x0020 -#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK) - -#define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK -#define SYSFS_FLAG_REMOVED 0x0100 - #ifdef CONFIG_SYSFS -extern int sysfs_schedule_callback(struct kobject *kobj, - void (*func)(void *), void *data, struct module *owner); - -extern int __must_check -sysfs_create_dir(struct kobject *); - -extern void -sysfs_remove_dir(struct kobject *); - -extern int __must_check -sysfs_rename_dir(struct kobject *kobj, const char *new_name); - -extern int __must_check -sysfs_move_dir(struct kobject *, struct kobject *); - -extern int __must_check -sysfs_create_file(struct kobject *, const struct attribute *); - -extern int __must_check -sysfs_update_file(struct kobject *, const struct attribute *); +int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), + void *data, struct module *owner); -extern int __must_check -sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode); +int __must_check sysfs_create_dir(struct kobject *kobj); +void sysfs_remove_dir(struct kobject *kobj); +int __must_check sysfs_rename_dir(struct kobject *kobj, const char *new_name); +int __must_check sysfs_move_dir(struct kobject *kobj, + struct kobject *new_parent_kobj); -extern void -sysfs_remove_file(struct kobject *, const struct attribute *); - -extern int __must_check -sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name); - -extern void -sysfs_remove_link(struct kobject *, const char * name); +int __must_check sysfs_create_file(struct kobject *kobj, + const struct attribute *attr); +int __must_check sysfs_update_file(struct kobject *kobj, + const struct attribute *attr); +int __must_check sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, + mode_t mode); +void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr); int __must_check sysfs_create_bin_file(struct kobject *kobj, - struct bin_attribute *attr); + struct bin_attribute *attr); void sysfs_remove_bin_file(struct kobject *kobj, struct bin_attribute *attr); -int __must_check sysfs_create_group(struct kobject *, - const struct attribute_group *); -void sysfs_remove_group(struct kobject *, const struct attribute_group *); +int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target, + const char *name); +void sysfs_remove_link(struct kobject *kobj, const char *name); + +int __must_check sysfs_create_group(struct kobject *kobj, + const struct attribute_group *grp); +void sysfs_remove_group(struct kobject *kobj, + const struct attribute_group *grp); int sysfs_add_file_to_group(struct kobject *kobj, - const struct attribute *attr, const char *group); + const struct attribute *attr, const char *group); void sysfs_remove_file_from_group(struct kobject *kobj, - const struct attribute *attr, const char *group); + const struct attribute *attr, const char *group); -void sysfs_notify(struct kobject * k, char *dir, char *attr); +void sysfs_notify(struct kobject *kobj, char *dir, char *attr); extern int __must_check sysfs_init(void); @@ -144,72 +122,81 @@ static inline int sysfs_schedule_callback(struct kobject *kobj, return -ENOSYS; } -static inline int sysfs_create_dir(struct kobject * kobj) +static inline int sysfs_create_dir(struct kobject *kobj) { return 0; } -static inline void sysfs_remove_dir(struct kobject * k) +static inline void sysfs_remove_dir(struct kobject *kobj) { ; } -static inline int sysfs_rename_dir(struct kobject * kobj, const char *new_name) +static inline int sysfs_rename_dir(struct kobject *kobj, const char *new_name) { return 0; } -static inline int sysfs_move_dir(struct kobject * k, struct kobject * new_parent) +static inline int sysfs_move_dir(struct kobject *kobj, + struct kobject *new_parent_kobj) { return 0; } -static inline int sysfs_create_file(struct kobject * k, const struct attribute * a) +static inline int sysfs_create_file(struct kobject *kobj, + const struct attribute *attr) { return 0; } -static inline int sysfs_update_file(struct kobject * k, const struct attribute * a) +static inline int sysfs_update_file(struct kobject *kobj, + const struct attribute *attr) { return 0; } -static inline int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode) +static inline int sysfs_chmod_file(struct kobject *kobj, + struct attribute *attr, mode_t mode) { return 0; } -static inline void sysfs_remove_file(struct kobject * k, const struct attribute * a) +static inline void sysfs_remove_file(struct kobject *kobj, + const struct attribute *attr) { ; } -static inline int sysfs_create_link(struct kobject * k, struct kobject * t, const char * n) +static inline int sysfs_create_bin_file(struct kobject *kobj, + struct bin_attribute *attr) { return 0; } -static inline void sysfs_remove_link(struct kobject * k, const char * name) +static inline int sysfs_remove_bin_file(struct kobject *kobj, + struct bin_attribute *attr) { - ; + return 0; } - -static inline int sysfs_create_bin_file(struct kobject * k, struct bin_attribute * a) +static inline int sysfs_create_link(struct kobject *kobj, + struct kobject *target, const char *name) { return 0; } -static inline int sysfs_remove_bin_file(struct kobject * k, struct bin_attribute * a) +static inline void sysfs_remove_link(struct kobject *kobj, const char *name) { - return 0; + ; } -static inline int sysfs_create_group(struct kobject * k, const struct attribute_group *g) +static inline int sysfs_create_group(struct kobject *kobj, + const struct attribute_group *grp) { return 0; } -static inline void sysfs_remove_group(struct kobject * k, const struct attribute_group * g) +static inline void sysfs_remove_group(struct kobject *kobj, + const struct attribute_group *grp) { ; } @@ -225,7 +212,7 @@ static inline void sysfs_remove_file_from_group(struct kobject *kobj, { } -static inline void sysfs_notify(struct kobject * k, char *dir, char *attr) +static inline void sysfs_notify(struct kobject *kobj, char *dir, char *attr) { } -- cgit v1.2.3-70-g09d2 From b13dc89c5a5bd5e34aadb44c0fb7e870959dcd06 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:10 +0900 Subject: sysfs: reposition sysfs_dirent->s_mode. Move s_mode downward such that it's side-by-side with s_iattr which is used for the same thing. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/sysfs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 63adbecc9ba..6cf61c882ba 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -39,8 +39,8 @@ struct sysfs_dirent { } s_elem; unsigned int s_flags; - umode_t s_mode; ino_t s_ino; + umode_t s_mode; struct iattr *s_iattr; atomic_t s_event; }; -- cgit v1.2.3-70-g09d2 From b1fc3d6144d56360d1373b01c7881826f558b6cd Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:11 +0900 Subject: sysfs: make s_elem an anonymous union Make s_elem an anonymous union. Prefixing with s_elem makes things needlessly longer without any advantage. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/bin.c | 14 +++++++------- fs/sysfs/dir.c | 4 ++-- fs/sysfs/file.c | 14 +++++++------- fs/sysfs/inode.c | 2 +- fs/sysfs/symlink.c | 4 ++-- fs/sysfs/sysfs.h | 10 +++++----- 6 files changed, 24 insertions(+), 24 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 9c8f8824e66..247ea19721c 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -30,8 +30,8 @@ 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 +87,8 @@ 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 +140,8 @@ 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); @@ -167,7 +167,7 @@ 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; diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index fc615eed67d..6ee76a82eb3 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -273,7 +273,7 @@ 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); @@ -630,7 +630,7 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, sd = sysfs_new_dirent(name, mode, SYSFS_DIR); if (!sd) return -ENOMEM; - sd->s_elem.dir.kobj = kobj; + sd->s_dir.kobj = kobj; /* link in */ sysfs_addrm_start(&acxt, parent_sd); diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 8f1ebd88b9c..3c91a57a1ed 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -73,7 +73,7 @@ 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; @@ -88,7 +88,7 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer return -ENODEV; buffer->event = atomic_read(&attr_sd->s_event); - count = ops->show(kobj, attr_sd->s_elem.attr.attr, buffer->page); + count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page); sysfs_put_active_two(attr_sd); @@ -188,7 +188,7 @@ 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; @@ -196,7 +196,7 @@ 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); @@ -240,7 +240,7 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t 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; @@ -336,7 +336,7 @@ 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 kobject *kobj = attr_sd->s_parent->s_dir.kobj; /* need parent for the kobj, grab both */ if (!sysfs_get_active_two(attr_sd)) @@ -396,7 +396,7 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, 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); diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 0d706a86d2c..b6ac4e6d6e7 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -172,7 +172,7 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) inode->i_fop = &sysfs_file_operations; break; case SYSFS_KOBJ_BIN_ATTR: - bin_attr = sd->s_elem.bin_attr.bin_attr; + bin_attr = sd->s_bin_attr.bin_attr; inode->i_size = bin_attr->size; inode->i_fop = &bin_fops; break; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index 8ad38bccc0e..ffa82e9802a 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -86,7 +86,7 @@ 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); @@ -142,7 +142,7 @@ 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 6cf61c882ba..2a68bfa46e4 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -32,11 +32,11 @@ struct sysfs_dirent { 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; ino_t s_ino; -- cgit v1.2.3-70-g09d2 From dc2f75f0e0cac645c22c85bcf429683b3fa0d2d9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:12 +0900 Subject: sysfs: make sysfs_root a regular directory dirent sysfs_root is different from a regular directory dirent in that it's of type SYSFS_ROOT and doesn't have a name. These differences aren't used by anybody and only adds to complexity. Make sysfs_root a regular directory dirent. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/inode.c | 5 ----- fs/sysfs/mount.c | 3 ++- fs/sysfs/sysfs.h | 9 ++++----- 3 files changed, 6 insertions(+), 11 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index b6ac4e6d6e7..c40fb9fdd04 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -157,11 +157,6 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) /* initialize inode according to type */ switch (sysfs_type(sd)) { - case SYSFS_ROOT: - inode->i_op = &sysfs_dir_inode_operations; - inode->i_fop = &sysfs_dir_operations; - inc_nlink(inode); /* directory, account for "." */ - break; case SYSFS_DIR: inode->i_op = &sysfs_dir_inode_operations; inode->i_fop = &sysfs_dir_operations; diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 28bf359981f..465902c18d3 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -24,8 +24,9 @@ static const struct super_operations sysfs_ops = { }; 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, }; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 2a68bfa46e4..60405a6e4c2 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -48,11 +48,10 @@ struct sysfs_dirent { #define SD_DEACTIVATED_BIAS INT_MIN #define SYSFS_TYPE_MASK 0x00ff -#define SYSFS_ROOT 0x0001 -#define SYSFS_DIR 0x0002 -#define SYSFS_KOBJ_ATTR 0x0004 -#define SYSFS_KOBJ_BIN_ATTR 0x0008 -#define SYSFS_KOBJ_LINK 0x0020 +#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 -- cgit v1.2.3-70-g09d2 From bc747f37a0f089b9366f7385ff870e12911f2383 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:12 +0900 Subject: sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir Children list head is only meaninful for directory nodes. Move it into s_dir. This doesn't save any space currently but it will with further changes. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 17 +++++++++-------- fs/sysfs/inode.c | 2 +- fs/sysfs/sysfs.h | 3 ++- 3 files changed, 12 insertions(+), 10 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 48a3ed4f453..4ad9422566a 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -26,7 +26,7 @@ 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) @@ -40,9 +40,9 @@ static void sysfs_link_sibling(struct sysfs_dirent *sd) /* Store directory entries in order by ino. This allows * readdir to properly restart without having to add a - * cursor into the s_children list. + * cursor into the s_dir.children list. */ - for (pos = &parent_sd->s_children; *pos; pos = &(*pos)->s_sibling) { + for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) { if (sd->s_ino < (*pos)->s_ino) break; } @@ -55,7 +55,7 @@ static 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) @@ -64,7 +64,8 @@ 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; @@ -570,7 +571,7 @@ 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) + for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) if (!strcmp(sd->s_name, name)) return sd; return NULL; @@ -722,7 +723,7 @@ 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; @@ -922,7 +923,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) mutex_lock(&sysfs_mutex); /* Skip the dentries we have already reported */ - pos = parent_sd->s_children; + pos = parent_sd->s_dir.children; while (pos && (filp->f_pos > pos->s_ino)) pos = pos->s_sibling; diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index c40fb9fdd04..2210cf0005f 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -127,7 +127,7 @@ 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) + for (child = sd->s_dir.children; child; child = child->s_sibling) if (sysfs_type(child) == SYSFS_DIR) nr++; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 60405a6e4c2..42b0327d162 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -1,6 +1,8 @@ /* type-specific structures for sysfs_dirent->s_* union members */ struct sysfs_elem_dir { struct kobject *kobj; + /* children list starts here and goes through sd->s_sibling */ + struct sysfs_dirent *children; }; struct sysfs_elem_symlink { @@ -28,7 +30,6 @@ struct sysfs_dirent { atomic_t s_active; struct sysfs_dirent *s_parent; struct sysfs_dirent *s_sibling; - struct sysfs_dirent *s_children; const char *s_name; union { -- cgit v1.2.3-70-g09d2 From 85a4ffad3de77177591f7c2c18c26c3c8dd28bff Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:12 +0900 Subject: sysfs: implement sysfs_open_dirent Implement sysfs_open_dirent which represents an open file (attribute) sysfs_dirent. A file sysfs_dirent with one or more open files have one sysfs_dirent and all sysfs_buffers (one for each open instance) are linked to it. sysfs_open_dirent doesn't actually do anything yet but will be used to off-load things which are specific for open file sysfs_dirent from it. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- fs/sysfs/sysfs.h | 3 ++ 2 files changed, 111 insertions(+), 1 deletion(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 3c91a57a1ed..b13ba94cf8a 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -49,6 +49,22 @@ 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; + struct list_head buffers; /* goes through sysfs_buffer.list */ +}; + struct sysfs_buffer { size_t count; loff_t pos; @@ -57,6 +73,7 @@ struct sysfs_buffer { struct mutex mutex; int needs_read_fill; int event; + struct list_head list; }; /** @@ -237,6 +254,86 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t 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); + 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; @@ -298,19 +395,29 @@ static int sysfs_open_file(struct inode *inode, struct file *file) buffer->ops = ops; file->private_data = buffer; + /* 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); 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 *sd = filp->f_path.dentry->d_fsdata; struct sysfs_buffer *buffer = filp->private_data; + sysfs_put_open_dirent(sd, buffer); + if (buffer->page) free_page((unsigned long)buffer->page); kfree(buffer); diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 42b0327d162..3adce7d5e4f 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -1,3 +1,5 @@ +struct sysfs_open_dirent; + /* type-specific structures for sysfs_dirent->s_* union members */ struct sysfs_elem_dir { struct kobject *kobj; @@ -11,6 +13,7 @@ struct sysfs_elem_symlink { struct sysfs_elem_attr { struct attribute *attr; + struct sysfs_open_dirent *open; }; struct sysfs_elem_bin_attr { -- cgit v1.2.3-70-g09d2 From a4e8b912541d5372ae049a3b7c1979968e52c40b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 16:05:12 +0900 Subject: sysfs: move sysfs file poll implementation to sysfs_open_dirent Sysfs file poll implementation is scattered over sysfs and kobject. Event numbering is done in sysfs_dirent but wait itself is done on kobject. This not only unecessarily bloats both kobject and sysfs_dirent but is also buggy - if a sysfs_dirent is removed while there still are pollers, the associaton betwen the kobject and sysfs_dirent breaks and kobject may be freed with the pollers still sleeping on it. This patch moves whole poll implementation into sysfs_open_dirent. Each time a sysfs_open_dirent is created, event number restarts from 1 and pollers sleep on sysfs_open_dirent. As event sequence number is meaningless without any open file and pollers should have open file and thus sysfs_open_dirent, this ephemeral event counting works and is a saner implementation. This patch fixes the dnagling sleepers bug and reduces the sizes of kobject and sysfs_dirent by one pointer. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 1 - fs/sysfs/file.c | 25 +++++++++++++++++++------ fs/sysfs/sysfs.h | 1 - include/linux/kobject.h | 1 - lib/kobject.c | 1 - 5 files changed, 19 insertions(+), 10 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 4ad9422566a..e301a1207b6 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -318,7 +318,6 @@ 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; diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index b13ba94cf8a..c05f9618b2d 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -62,6 +62,8 @@ 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 */ }; @@ -104,7 +106,7 @@ 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); + 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); @@ -301,6 +303,8 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd, 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; } @@ -443,17 +447,17 @@ 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_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; @@ -474,8 +478,17 @@ 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); diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 3adce7d5e4f..269c845c590 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -46,7 +46,6 @@ struct sysfs_dirent { ino_t s_ino; umode_t s_mode; struct iattr *s_iattr; - atomic_t s_event; }; #define SD_DEACTIVATED_BIAS INT_MIN diff --git a/include/linux/kobject.h b/include/linux/kobject.h index 0777b3f57ae..a8a84fcccbc 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -66,7 +66,6 @@ struct kobject { struct kset * kset; struct kobj_type * ktype; struct sysfs_dirent * sd; - wait_queue_head_t poll; }; extern int kobject_set_name(struct kobject *, const char *, ...) diff --git a/lib/kobject.c b/lib/kobject.c index e8181d3cec3..fc6db6b4bfc 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -131,7 +131,6 @@ void kobject_init(struct kobject * kobj) return; kref_init(&kobj->kref); INIT_LIST_HEAD(&kobj->entry); - init_waitqueue_head(&kobj->poll); kobj->kset = kset_get(kobj->kset); } -- cgit v1.2.3-70-g09d2 From 6d66f5cd26e4c482e986130b7572f2735a0f7e8b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 20 Sep 2007 17:31:38 +0900 Subject: sysfs: add copyrights Sysfs has gone through considerable amount of reimplementation. Add copyrights. Any objections? :-) Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/bin.c | 8 +++++++- fs/sysfs/dir.c | 10 +++++++++- fs/sysfs/file.c | 10 +++++++++- fs/sysfs/inode.c | 8 ++++++-- fs/sysfs/mount.c | 10 +++++++++- fs/sysfs/symlink.c | 10 +++++++++- fs/sysfs/sysfs.h | 10 ++++++++++ include/linux/sysfs.h | 2 ++ 8 files changed, 61 insertions(+), 7 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 247ea19721c..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 + * + * This file is released under the GPLv2. + * + * Please see Documentation/filesystems/sysfs.txt for more information. */ #undef DEBUG diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index e301a1207b6..9161db4d6b5 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 + * + * This file is released under the GPLv2. + * + * Please see Documentation/filesystems/sysfs.txt for more information. */ #undef DEBUG diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index c05f9618b2d..d3be1e7fb48 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -1,5 +1,13 @@ /* - * 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 + * + * This file is released under the GPLv2. + * + * Please see Documentation/filesystems/sysfs.txt for more information. */ #include diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 2210cf0005f..9236635111f 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 + * + * This file is released under the GPLv2. * * Please see Documentation/filesystems/sysfs.txt for more information. */ diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 465902c18d3..c76c540be3c 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 + * + * This file is released under the GPLv2. + * + * Please see Documentation/filesystems/sysfs.txt for more information. */ #define DEBUG diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index ffa82e9802a..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 + * + * This file is released under the GPLv2. + * + * Please see Documentation/filesystems/sysfs.txt for more information. */ #include diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 269c845c590..f0326f281d1 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -1,3 +1,13 @@ +/* + * 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 + * + * This file is released under the GPLv2. + */ + struct sysfs_open_dirent; /* type-specific structures for sysfs_dirent->s_* union members */ diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index db5dd2403d0..149ab62329e 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -3,6 +3,8 @@ * * Copyright (c) 2001,2002 Patrick Mochel * Copyright (c) 2004 Silicon Graphics, Inc. + * Copyright (c) 2007 SUSE Linux Products GmbH + * Copyright (c) 2007 Tejun Heo * * Please see Documentation/filesystems/sysfs.txt for more information. */ -- cgit v1.2.3-70-g09d2