From a8104a9fcdeb82e22d7acd55fca20746581067d3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 20 Jul 2012 02:25:00 +0400 Subject: pull mnt_want_write()/mnt_drop_write() into kern_path_create()/done_path_create() resp. One side effect - attempt to create a cross-device link on a read-only fs fails with EROFS instead of EXDEV now. Makes more sense, POSIX allows, etc. Signed-off-by: Al Viro --- fs/namei.c | 57 ++++++++++++++++++--------------------------------------- 1 file changed, 18 insertions(+), 39 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/namei.c b/fs/namei.c index cf362dc9d1f..a3fb78fd70d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2865,10 +2865,11 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); if (IS_ERR(dentry)) - goto fail; + goto unlock; + error = -EEXIST; if (dentry->d_inode) - goto eexist; + goto fail; /* * Special case - lookup gave negative, but... we had foo/bar/ * From the vfs_mknod() POV we just have a negative dentry - @@ -2876,16 +2877,18 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path * been asking for (non-existent) directory. -ENOENT for you. */ if (unlikely(!is_dir && nd.last.name[nd.last.len])) { - dput(dentry); - dentry = ERR_PTR(-ENOENT); + error = -ENOENT; goto fail; } + error = mnt_want_write(nd.path.mnt); + if (error) + goto fail; *path = nd.path; return dentry; -eexist: - dput(dentry); - dentry = ERR_PTR(-EEXIST); fail: + dput(dentry); + dentry = ERR_PTR(error); +unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); out: path_put(&nd.path); @@ -2897,6 +2900,7 @@ void done_path_create(struct path *path, struct dentry *dentry) { dput(dentry); mutex_unlock(&path->dentry->d_inode->i_mutex); + mnt_drop_write(path->mnt); path_put(path); } EXPORT_SYMBOL(done_path_create); @@ -2974,12 +2978,9 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, if (!IS_POSIXACL(path.dentry->d_inode)) mode &= ~current_umask(); - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; error = security_path_mknod(&path, dentry, mode, dev); if (error) - goto out_drop_write; + goto out; switch (mode & S_IFMT) { case 0: case S_IFREG: error = vfs_create(path.dentry->d_inode,dentry,mode,true); @@ -2992,11 +2993,8 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, error = vfs_mknod(path.dentry->d_inode,dentry,mode,0); break; } -out_drop_write: - mnt_drop_write(path.mnt); -out_dput: +out: done_path_create(&path, dentry); - return error; } @@ -3042,16 +3040,9 @@ SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) if (!IS_POSIXACL(path.dentry->d_inode)) mode &= ~current_umask(); - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; error = security_path_mkdir(&path, dentry, mode); - if (error) - goto out_drop_write; - error = vfs_mkdir(path.dentry->d_inode, dentry, mode); -out_drop_write: - mnt_drop_write(path.mnt); -out_dput: + if (!error) + error = vfs_mkdir(path.dentry->d_inode, dentry, mode); done_path_create(&path, dentry); return error; } @@ -3326,16 +3317,9 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, if (IS_ERR(dentry)) goto out_putname; - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; error = security_path_symlink(&path, dentry, from); - if (error) - goto out_drop_write; - error = vfs_symlink(path.dentry->d_inode, dentry, from); -out_drop_write: - mnt_drop_write(path.mnt); -out_dput: + if (!error) + error = vfs_symlink(path.dentry->d_inode, dentry, from); done_path_create(&path, dentry); out_putname: putname(from); @@ -3436,15 +3420,10 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, error = -EXDEV; if (old_path.mnt != new_path.mnt) goto out_dput; - error = mnt_want_write(new_path.mnt); - if (error) - goto out_dput; error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) - goto out_drop_write; + goto out_dput; error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry); -out_drop_write: - mnt_drop_write(new_path.mnt); out_dput: done_path_create(&new_path, new_dentry); out: -- cgit v1.2.3