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authorEric Biggers <ebiggers3@gmail.com>2014-10-12 20:59:58 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2014-10-13 01:09:10 +0400
commit8cc431165d8fbda43634dd15ab17f76a151c39a8 (patch)
tree9f75709e432ec0beed0923e935b3d63d45b4b3e7
parent50b220bbe7092bbfe4406adfe3a216337a64655d (diff)
downloadlinux-8cc431165d8fbda43634dd15ab17f76a151c39a8.tar.xz
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 <ebiggers3@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/xattr.c116
1 files 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)