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authorDave Hansen <haveblue@us.ibm.com>2006-09-30 23:29:01 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-01 00:39:30 -0700
commit6902d925d568cd5bfda8a1a328bf08d26d1bab46 (patch)
tree02f3cc489d0e47fb688587222d1793bd9298679b
parentdb5fed26b2e0beed939b773dd5896077a1794d65 (diff)
downloadop-kernel-dev-6902d925d568cd5bfda8a1a328bf08d26d1bab46.zip
op-kernel-dev-6902d925d568cd5bfda8a1a328bf08d26d1bab46.tar.gz
[PATCH] r/o bind mounts: prepare for write access checks: collapse if()
We're shortly going to be adding a bunch more permission checks in these functions. That requires adding either a bunch of new if() conditions, or some gotos. This patch collapses existing if()s and uses gotos instead to prepare for the upcoming changes. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/namei.c93
-rw-r--r--fs/open.c64
2 files changed, 87 insertions, 70 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 2892e68..7bdceed 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1934,30 +1934,32 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
{
int error = 0;
char * tmp;
+ struct dentry *dentry;
+ struct nameidata nd;
tmp = getname(pathname);
error = PTR_ERR(tmp);
- if (!IS_ERR(tmp)) {
- struct dentry *dentry;
- struct nameidata nd;
+ if (IS_ERR(tmp))
+ goto out_err;
- error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
- dentry = lookup_create(&nd, 1);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- if (!IS_POSIXACL(nd.dentry->d_inode))
- mode &= ~current->fs->umask;
- error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
- dput(dentry);
- }
- mutex_unlock(&nd.dentry->d_inode->i_mutex);
- path_release(&nd);
-out:
- putname(tmp);
- }
+ error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
+ if (error)
+ goto out;
+ dentry = lookup_create(&nd, 1);
+ error = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+ if (!IS_POSIXACL(nd.dentry->d_inode))
+ mode &= ~current->fs->umask;
+ error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
+ dput(dentry);
+out_unlock:
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
+ path_release(&nd);
+out:
+ putname(tmp);
+out_err:
return error;
}
@@ -2056,10 +2058,11 @@ static long do_rmdir(int dfd, const char __user *pathname)
mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- error = vfs_rmdir(nd.dentry->d_inode, dentry);
- dput(dentry);
- }
+ if (IS_ERR(dentry))
+ goto exit2;
+ error = vfs_rmdir(nd.dentry->d_inode, dentry);
+ dput(dentry);
+exit2:
mutex_unlock(&nd.dentry->d_inode->i_mutex);
exit1:
path_release(&nd);
@@ -2199,30 +2202,33 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
int error = 0;
char * from;
char * to;
+ struct dentry *dentry;
+ struct nameidata nd;
from = getname(oldname);
if(IS_ERR(from))
return PTR_ERR(from);
to = getname(newname);
error = PTR_ERR(to);
- if (!IS_ERR(to)) {
- struct dentry *dentry;
- struct nameidata nd;
+ if (IS_ERR(to))
+ goto out_putname;
- error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
- dentry = lookup_create(&nd, 0);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
- dput(dentry);
- }
- mutex_unlock(&nd.dentry->d_inode->i_mutex);
- path_release(&nd);
+ error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+ if (error)
+ goto out;
+ dentry = lookup_create(&nd, 0);
+ error = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+
+ error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
+ dput(dentry);
+out_unlock:
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
+ path_release(&nd);
out:
- putname(to);
- }
+ putname(to);
+out_putname:
putname(from);
return error;
}
@@ -2308,10 +2314,11 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
goto out_release;
new_dentry = lookup_create(&nd, 0);
error = PTR_ERR(new_dentry);
- if (!IS_ERR(new_dentry)) {
- error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
- dput(new_dentry);
- }
+ if (IS_ERR(new_dentry))
+ goto out_unlock;
+ error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+ dput(new_dentry);
+out_unlock:
mutex_unlock(&nd.dentry->d_inode->i_mutex);
out_release:
path_release(&nd);
diff --git a/fs/open.c b/fs/open.c
index 35c3e45..89e0c23 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -386,15 +386,21 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
current->cap_effective = current->cap_permitted;
res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd);
- if (!res) {
- 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))
- res = -EROFS;
- path_release(&nd);
- }
+ if (res)
+ goto out;
+
+ res = vfs_permission(&nd, mode);
+ /* SuS v2 requires we report a read only fs too */
+ if(res || !(mode & S_IWOTH) ||
+ special_file(nd.dentry->d_inode->i_mode))
+ goto out_path_release;
+
+ if(IS_RDONLY(nd.dentry->d_inode))
+ res = -EROFS;
+out_path_release:
+ path_release(&nd);
+out:
current->fsuid = old_fsuid;
current->fsgid = old_fsgid;
current->cap_effective = old_cap;
@@ -603,10 +609,11 @@ asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group)
int error;
error = user_path_walk(filename, &nd);
- if (!error) {
- error = chown_common(nd.dentry, user, group);
- path_release(&nd);
- }
+ if (error)
+ goto out;
+ error = chown_common(nd.dentry, user, group);
+ path_release(&nd);
+out:
return error;
}
@@ -622,10 +629,10 @@ asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user,
follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
error = __user_walk_fd(dfd, filename, follow, &nd);
- if (!error) {
- error = chown_common(nd.dentry, user, group);
- path_release(&nd);
- }
+ if (error)
+ goto out;
+ error = chown_common(nd.dentry, user, group);
+ path_release(&nd);
out:
return error;
}
@@ -636,10 +643,11 @@ asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group
int error;
error = user_path_walk_link(filename, &nd);
- if (!error) {
- error = chown_common(nd.dentry, user, group);
- path_release(&nd);
- }
+ if (error)
+ goto out;
+ error = chown_common(nd.dentry, user, group);
+ path_release(&nd);
+out:
return error;
}
@@ -648,15 +656,17 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
{
struct file * file;
int error = -EBADF;
+ struct dentry * dentry;
file = fget(fd);
- if (file) {
- struct dentry * dentry;
- dentry = file->f_dentry;
- audit_inode(NULL, dentry->d_inode);
- error = chown_common(dentry, user, group);
- fput(file);
- }
+ if (!file)
+ goto out;
+
+ dentry = file->f_dentry;
+ audit_inode(NULL, dentry->d_inode);
+ error = chown_common(dentry, user, group);
+ fput(file);
+out:
return error;
}
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