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author | 2005-11-08 21:35:04 -0800 | |
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committer | 2005-11-09 07:55:58 -0800 | |
commit | e4543eddfd3bf3e0d625841377fa695a519edfd4 (patch) | |
tree | b62546cb0038529bd8cd583333c556ad799f2081 /fs | |
parent | [PATCH] drivers/block/pktcdvd.c: remove write-only variable in pkt_iosched_pr... (diff) | |
download | linux-e4543eddfd3bf3e0d625841377fa695a519edfd4.tar.gz linux-e4543eddfd3bf3e0d625841377fa695a519edfd4.tar.bz2 linux-e4543eddfd3bf3e0d625841377fa695a519edfd4.zip |
[PATCH] add a vfs_permission helper
Most permission() calls have a struct nameidata * available. This helper
takes that as an argument and thus makes sure we pass it down for lookup
intents and prepares for per-mount read-only support where we need a struct
vfsmount for checking whether a file is writeable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/exec.c | 4 | ||||
-rw-r--r-- | fs/inotify.c | 2 | ||||
-rw-r--r-- | fs/namei.c | 23 | ||||
-rw-r--r-- | fs/namespace.c | 2 | ||||
-rw-r--r-- | fs/open.c | 12 |
5 files changed, 29 insertions, 14 deletions
diff --git a/fs/exec.c b/fs/exec.c index 5a4e3acc2e9f..7bbb781b9ac6 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -135,7 +135,7 @@ asmlinkage long sys_uselib(const char __user * library) if (!S_ISREG(nd.dentry->d_inode->i_mode)) goto exit; - error = permission(nd.dentry->d_inode, MAY_READ | MAY_EXEC, &nd); + error = vfs_permission(&nd, MAY_READ | MAY_EXEC); if (error) goto exit; @@ -495,7 +495,7 @@ struct file *open_exec(const char *name) file = ERR_PTR(-EACCES); if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && S_ISREG(inode->i_mode)) { - int err = permission(inode, MAY_EXEC, &nd); + int err = vfs_permission(&nd, MAY_EXEC); if (!err && !(inode->i_mode & 0111)) err = -EACCES; file = ERR_PTR(err); diff --git a/fs/inotify.c b/fs/inotify.c index 9fbaebfdf40b..bf7ce1d2412b 100644 --- a/fs/inotify.c +++ b/fs/inotify.c @@ -372,7 +372,7 @@ static int find_inode(const char __user *dirname, struct nameidata *nd) if (error) return error; /* you can only watch an inode if you have read permissions on it */ - error = permission(nd->dentry->d_inode, MAY_READ, NULL); + error = vfs_permission(nd, MAY_READ); if (error) path_release(nd); return error; diff --git a/fs/namei.c b/fs/namei.c index b3f8a1966c9c..25e4ab4ce8b7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -256,6 +256,21 @@ int permission(struct inode *inode, int mask, struct nameidata *nd) return security_inode_permission(inode, mask, nd); } +/** + * vfs_permission - check for access rights to a given path + * @nd: lookup result that describes the path + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on a path. + * We use "fsuid" for this, letting us set arbitrary permissions + * for filesystem access without changing the "normal" uids which + * are used for other things. + */ +int vfs_permission(struct nameidata *nd, int mask) +{ + return permission(nd->dentry->d_inode, mask, nd); +} + /* * get_write_access() gets write permission for a file. * put_write_access() releases this write permission. @@ -765,9 +780,8 @@ static fastcall int __link_path_walk(const char * name, struct nameidata *nd) nd->flags |= LOOKUP_CONTINUE; err = exec_permission_lite(inode, nd); - if (err == -EAGAIN) { - err = permission(inode, MAY_EXEC, nd); - } + if (err == -EAGAIN) + err = vfs_permission(nd, MAY_EXEC); if (err) break; @@ -1407,7 +1421,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (S_ISDIR(inode->i_mode) && (flag & FMODE_WRITE)) return -EISDIR; - error = permission(inode, acc_mode, nd); + error = vfs_permission(nd, acc_mode); if (error) return error; @@ -2536,6 +2550,7 @@ EXPORT_SYMBOL(path_lookup); EXPORT_SYMBOL(path_release); EXPORT_SYMBOL(path_walk); EXPORT_SYMBOL(permission); +EXPORT_SYMBOL(vfs_permission); EXPORT_SYMBOL(unlock_rename); EXPORT_SYMBOL(vfs_create); EXPORT_SYMBOL(vfs_follow_link); diff --git a/fs/namespace.c b/fs/namespace.c index caa9187f67e5..2019899f2ab8 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -637,7 +637,7 @@ static int mount_is_safe(struct nameidata *nd) if (current->uid != nd->dentry->d_inode->i_uid) return -EPERM; } - if (permission(nd->dentry->d_inode, MAY_WRITE, nd)) + if (vfs_permission(nd, MAY_WRITE)) return -EPERM; return 0; #endif diff --git a/fs/open.c b/fs/open.c index 6e8136751e9a..baffc084580d 100644 --- a/fs/open.c +++ b/fs/open.c @@ -240,7 +240,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length) if (!S_ISREG(inode->i_mode)) goto dput_and_out; - error = permission(inode,MAY_WRITE,&nd); + error = vfs_permission(&nd, MAY_WRITE); if (error) goto dput_and_out; @@ -394,7 +394,7 @@ asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) goto dput_and_out; if (current->fsuid != inode->i_uid && - (error = permission(inode,MAY_WRITE,&nd)) != 0) + (error = vfs_permission(&nd, MAY_WRITE)) != 0) goto dput_and_out; } down(&inode->i_sem); @@ -447,7 +447,7 @@ long do_utimes(char __user * filename, struct timeval * times) goto dput_and_out; if (current->fsuid != inode->i_uid && - (error = permission(inode,MAY_WRITE,&nd)) != 0) + (error = vfs_permission(&nd, MAY_WRITE)) != 0) goto dput_and_out; } down(&inode->i_sem); @@ -506,7 +506,7 @@ asmlinkage long sys_access(const char __user * filename, int mode) res = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); if (!res) { - res = permission(nd.dentry->d_inode, mode, &nd); + res = vfs_permission(&nd, mode); /* SuS v2 requires we report a read only fs too */ if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode) && !special_file(nd.dentry->d_inode->i_mode)) @@ -530,7 +530,7 @@ asmlinkage long sys_chdir(const char __user * filename) if (error) goto out; - error = permission(nd.dentry->d_inode,MAY_EXEC,&nd); + error = vfs_permission(&nd, MAY_EXEC); if (error) goto dput_and_out; @@ -581,7 +581,7 @@ asmlinkage long sys_chroot(const char __user * filename) if (error) goto out; - error = permission(nd.dentry->d_inode,MAY_EXEC,&nd); + error = vfs_permission(&nd, MAY_EXEC); if (error) goto dput_and_out; |