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| author | Christoph Hellwig <hch@lst.de> | 2005-11-08 21:35:04 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-09 07:55:58 -0800 |
| commit | e4543eddfd3bf3e0d625841377fa695a519edfd4 (patch) | |
| tree | b62546cb0038529bd8cd583333c556ad799f2081 /fs/namei.c | |
| parent | e4a53cbabc81f04e24a5570b4aa6a6384bdbfc67 (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/namei.c')
| -rw-r--r-- | fs/namei.c | 23 |
1 files changed, 19 insertions, 4 deletions
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); |