From 8cc431165d8fbda43634dd15ab17f76a151c39a8 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 12 Oct 2014 11:59:58 -0500 Subject: [PATCH] vfs: Deduplicate code shared by xattr system calls operating on paths The following pairs of system calls dealing with extended attributes only differ in their behavior on whether the symbolic link is followed (when the named file is a symbolic link): - setxattr() and lsetxattr() - getxattr() and lgetxattr() - listxattr() and llistxattr() - removexattr() and lremovexattr() Despite this, the implementations all had duplicated code, so this commit redirects each of the above pairs of system calls to a corresponding function to which different lookup flags (LOOKUP_FOLLOW or 0) are passed. For me this reduced the stripped size of xattr.o from 8824 to 8248 bytes. Signed-off-by: Eric Biggers Signed-off-by: Al Viro --- fs/xattr.c | 116 ++++++++++++++++++----------------------------------- 1 file changed, 39 insertions(+), 77 deletions(-) diff --git a/fs/xattr.c b/fs/xattr.c index c69e6d43a0d2..64e83efb742d 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -364,13 +364,12 @@ out: return error; } -SYSCALL_DEFINE5(setxattr, const char __user *, pathname, - const char __user *, name, const void __user *, value, - size_t, size, int, flags) +static int path_setxattr(const char __user *pathname, + const char __user *name, const void __user *value, + size_t size, int flags, unsigned int lookup_flags) { struct path path; int error; - unsigned int lookup_flags = LOOKUP_FOLLOW; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (error) @@ -388,28 +387,18 @@ retry: return error; } +SYSCALL_DEFINE5(setxattr, const char __user *, pathname, + const char __user *, name, const void __user *, value, + size_t, size, int, flags) +{ + return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW); +} + SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, const char __user *, name, const void __user *, value, size_t, size, int, flags) { - struct path path; - int error; - unsigned int lookup_flags = 0; -retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); - if (error) - return error; - error = mnt_want_write(path.mnt); - if (!error) { - error = setxattr(path.dentry, name, value, size, flags); - mnt_drop_write(path.mnt); - } - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } - return error; + return path_setxattr(pathname, name, value, size, flags, 0); } SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, @@ -481,12 +470,12 @@ getxattr(struct dentry *d, const char __user *name, void __user *value, return error; } -SYSCALL_DEFINE4(getxattr, const char __user *, pathname, - const char __user *, name, void __user *, value, size_t, size) +static ssize_t path_getxattr(const char __user *pathname, + const char __user *name, void __user *value, + size_t size, unsigned int lookup_flags) { struct path path; ssize_t error; - unsigned int lookup_flags = LOOKUP_FOLLOW; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (error) @@ -500,23 +489,16 @@ retry: return error; } +SYSCALL_DEFINE4(getxattr, const char __user *, pathname, + const char __user *, name, void __user *, value, size_t, size) +{ + return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW); +} + SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, const char __user *, name, void __user *, value, size_t, size) { - struct path path; - ssize_t error; - unsigned int lookup_flags = 0; -retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); - if (error) - return error; - error = getxattr(path.dentry, name, value, size); - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } - return error; + return path_getxattr(pathname, name, value, size, 0); } SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, @@ -571,12 +553,11 @@ listxattr(struct dentry *d, char __user *list, size_t size) return error; } -SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, - size_t, size) +static ssize_t path_listxattr(const char __user *pathname, char __user *list, + size_t size, unsigned int lookup_flags) { struct path path; ssize_t error; - unsigned int lookup_flags = LOOKUP_FOLLOW; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (error) @@ -590,23 +571,16 @@ retry: return error; } +SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, + size_t, size) +{ + return path_listxattr(pathname, list, size, LOOKUP_FOLLOW); +} + SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, size_t, size) { - struct path path; - ssize_t error; - unsigned int lookup_flags = 0; -retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); - if (error) - return error; - error = listxattr(path.dentry, list, size); - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } - return error; + return path_listxattr(pathname, list, size, 0); } SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) @@ -640,12 +614,11 @@ removexattr(struct dentry *d, const char __user *name) return vfs_removexattr(d, kname); } -SYSCALL_DEFINE2(removexattr, const char __user *, pathname, - const char __user *, name) +static int path_removexattr(const char __user *pathname, + const char __user *name, unsigned int lookup_flags) { struct path path; int error; - unsigned int lookup_flags = LOOKUP_FOLLOW; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (error) @@ -663,27 +636,16 @@ retry: return error; } +SYSCALL_DEFINE2(removexattr, const char __user *, pathname, + const char __user *, name) +{ + return path_removexattr(pathname, name, LOOKUP_FOLLOW); +} + SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, const char __user *, name) { - struct path path; - int error; - unsigned int lookup_flags = 0; -retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); - if (error) - return error; - error = mnt_want_write(path.mnt); - if (!error) { - error = removexattr(path.dentry, name); - mnt_drop_write(path.mnt); - } - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } - return error; + return path_removexattr(pathname, name, 0); } SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) -- 2.20.1