From 2072f1afddfe9fa00c1c0c79f8986707324ec65b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:35 -0500 Subject: [PATCH] sysfs, kernfs: move symlink core code to fs/kernfs/symlink.c Move core symlink code to fs/kernfs/symlink.c. fs/sysfs/symlink.c now only contains sysfs wrappers around kernfs interfaces. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/kernfs-internal.h | 5 ++ fs/kernfs/symlink.c | 139 ++++++++++++++++++++++++++++++++++++ fs/sysfs/symlink.c | 137 ----------------------------------- fs/sysfs/sysfs.h | 1 - 4 files changed, 144 insertions(+), 138 deletions(-) diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 38e3a163e5ad..62ae35f997f7 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -149,4 +149,9 @@ extern const struct file_operations kernfs_file_operations; void sysfs_unmap_bin_file(struct sysfs_dirent *sd); +/* + * symlink.c + */ +extern const struct inode_operations sysfs_symlink_inode_operations; + #endif /* __KERNFS_INTERNAL_H */ diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c index 2578715baf0e..af3570bb4303 100644 --- a/fs/kernfs/symlink.c +++ b/fs/kernfs/symlink.c @@ -7,3 +7,142 @@ * * This file is released under the GPLv2. */ + +#include +#include +#include + +#include "kernfs-internal.h" + +/** + * kernfs_create_link - create a symlink + * @parent: directory to create the symlink in + * @name: name of the symlink + * @target: target node for the symlink to point to + * + * Returns the created node on success, ERR_PTR() value on error. + */ +struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent, + const char *name, + struct sysfs_dirent *target) +{ + struct sysfs_dirent *sd; + struct sysfs_addrm_cxt acxt; + int error; + + sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); + if (!sd) + return ERR_PTR(-ENOMEM); + + if (parent->s_flags & SYSFS_FLAG_NS) + sd->s_ns = target->s_ns; + sd->s_symlink.target_sd = target; + kernfs_get(target); /* ref owned by symlink */ + + sysfs_addrm_start(&acxt); + error = sysfs_add_one(&acxt, sd, parent); + sysfs_addrm_finish(&acxt); + + if (!error) + return sd; + + kernfs_put(sd); + return ERR_PTR(error); +} + +static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, + struct sysfs_dirent *target_sd, char *path) +{ + struct sysfs_dirent *base, *sd; + char *s = path; + int len = 0; + + /* go up to the root, stop at the base */ + base = parent_sd; + while (base->s_parent) { + sd = target_sd->s_parent; + while (sd->s_parent && base != sd) + sd = sd->s_parent; + + if (base == sd) + break; + + strcpy(s, "../"); + s += 3; + base = base->s_parent; + } + + /* determine end of target string for reverse fillup */ + sd = target_sd; + while (sd->s_parent && sd != base) { + len += strlen(sd->s_name) + 1; + sd = sd->s_parent; + } + + /* check limits */ + if (len < 2) + return -EINVAL; + len--; + if ((s - path) + len > PATH_MAX) + return -ENAMETOOLONG; + + /* reverse fillup of target string from target to base */ + sd = target_sd; + while (sd->s_parent && sd != base) { + int slen = strlen(sd->s_name); + + len -= slen; + strncpy(s + len, sd->s_name, slen); + if (len) + s[--len] = '/'; + + sd = sd->s_parent; + } + + return 0; +} + +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_symlink.target_sd; + int error; + + mutex_lock(&sysfs_mutex); + error = sysfs_get_target_path(parent_sd, target_sd, path); + mutex_unlock(&sysfs_mutex); + + return error; +} + +static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + int error = -ENOMEM; + unsigned long page = get_zeroed_page(GFP_KERNEL); + if (page) { + error = sysfs_getlink(dentry, (char *) page); + if (error < 0) + free_page((unsigned long)page); + } + nd_set_link(nd, error ? ERR_PTR(error) : (char *)page); + return NULL; +} + +static void sysfs_put_link(struct dentry *dentry, struct nameidata *nd, + void *cookie) +{ + char *page = nd_get_link(nd); + if (!IS_ERR(page)) + free_page((unsigned long)page); +} + +const struct inode_operations sysfs_symlink_inode_operations = { + .setxattr = sysfs_setxattr, + .readlink = generic_readlink, + .follow_link = sysfs_follow_link, + .put_link = sysfs_put_link, + .setattr = sysfs_setattr, + .getattr = sysfs_getattr, + .permission = sysfs_permission, +}; diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c index b137aa3a486c..6797c9c2e43a 100644 --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -11,53 +11,13 @@ */ #include -#include -#include #include #include -#include #include #include #include "sysfs.h" -/** - * kernfs_create_link - create a symlink - * @parent: directory to create the symlink in - * @name: name of the symlink - * @target: target node for the symlink to point to - * - * Returns the created node on success, ERR_PTR() value on error. - */ -struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent, - const char *name, - struct sysfs_dirent *target) -{ - struct sysfs_dirent *sd; - struct sysfs_addrm_cxt acxt; - int error; - - sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); - if (!sd) - return ERR_PTR(-ENOMEM); - - if (parent->s_flags & SYSFS_FLAG_NS) - sd->s_ns = target->s_ns; - sd->s_symlink.target_sd = target; - kernfs_get(target); /* ref owned by symlink */ - - sysfs_addrm_start(&acxt); - error = sysfs_add_one(&acxt, sd, parent); - sysfs_addrm_finish(&acxt); - - if (!error) - return sd; - - kernfs_put(sd); - return ERR_PTR(error); -} - - static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, struct kobject *target, const char *name, int warn) @@ -235,100 +195,3 @@ out: return result; } EXPORT_SYMBOL_GPL(sysfs_rename_link_ns); - -static int sysfs_get_target_path(struct sysfs_dirent *parent_sd, - struct sysfs_dirent *target_sd, char *path) -{ - struct sysfs_dirent *base, *sd; - char *s = path; - int len = 0; - - /* go up to the root, stop at the base */ - base = parent_sd; - while (base->s_parent) { - sd = target_sd->s_parent; - while (sd->s_parent && base != sd) - sd = sd->s_parent; - - if (base == sd) - break; - - strcpy(s, "../"); - s += 3; - base = base->s_parent; - } - - /* determine end of target string for reverse fillup */ - sd = target_sd; - while (sd->s_parent && sd != base) { - len += strlen(sd->s_name) + 1; - sd = sd->s_parent; - } - - /* check limits */ - if (len < 2) - return -EINVAL; - len--; - if ((s - path) + len > PATH_MAX) - return -ENAMETOOLONG; - - /* reverse fillup of target string from target to base */ - sd = target_sd; - while (sd->s_parent && sd != base) { - int slen = strlen(sd->s_name); - - len -= slen; - strncpy(s + len, sd->s_name, slen); - if (len) - s[--len] = '/'; - - sd = sd->s_parent; - } - - return 0; -} - -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_symlink.target_sd; - int error; - - mutex_lock(&sysfs_mutex); - error = sysfs_get_target_path(parent_sd, target_sd, path); - mutex_unlock(&sysfs_mutex); - - return error; -} - -static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd) -{ - int error = -ENOMEM; - unsigned long page = get_zeroed_page(GFP_KERNEL); - if (page) { - error = sysfs_getlink(dentry, (char *) page); - if (error < 0) - free_page((unsigned long)page); - } - nd_set_link(nd, error ? ERR_PTR(error) : (char *)page); - return NULL; -} - -static void sysfs_put_link(struct dentry *dentry, struct nameidata *nd, - void *cookie) -{ - char *page = nd_get_link(nd); - if (!IS_ERR(page)) - free_page((unsigned long)page); -} - -const struct inode_operations sysfs_symlink_inode_operations = { - .setxattr = sysfs_setxattr, - .readlink = generic_readlink, - .follow_link = sysfs_follow_link, - .put_link = sysfs_put_link, - .setattr = sysfs_setattr, - .getattr = sysfs_getattr, - .permission = sysfs_permission, -}; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 4b8b60d834cc..6d0dcead2d6a 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -50,7 +50,6 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, /* * symlink.c */ -extern const struct inode_operations sysfs_symlink_inode_operations; int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target, const char *name);