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Subject[PATCH] more fs/super.c cleanups (3)
Chunk 3:
Takes the normal mounting into a helper similar to do_loopback()
et.al., makes do_mount() cleaner. Please, apply
Al

diff -urN S6-pre1-do_mount/fs/super.c S6-pre1-do_add_mount/fs/super.c
--- S6-pre1-do_mount/fs/super.c Tue Jun 5 08:15:33 2001
+++ S6-pre1-do_add_mount/fs/super.c Tue Jun 5 08:16:35 2001
@@ -1203,6 +1203,76 @@
return do_remount_sb(nd->mnt->mnt_sb, flags, data);
}

+static int do_add_mount(struct nameidata *nd, char *type, int flags,
+ char *name, void *data)
+{
+ struct file_system_type * fstype;
+ struct nameidata nd;
+ struct vfsmount *mnt = NULL;
+ struct super_block *sb;
+ int retval = 0;
+
+ if (!type || !memchr(type, 0, PAGE_SIZE))
+ return -EINVAL;
+
+ /* we need capabilities... */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* ... filesystem driver... */
+ fstype = get_fs_type(type);
+ if (!fstype)
+ return -ENODEV;
+
+ /* get superblock, locks mount_sem on success */
+ if (fstype->fs_flags & FS_NOMOUNT)
+ sb = ERR_PTR(-EINVAL);
+ else if (fstype->fs_flags & FS_REQUIRES_DEV)
+ sb = get_sb_bdev(fstype, name, flags, data);
+ else if (fstype->fs_flags & FS_SINGLE)
+ sb = get_sb_single(fstype, flags, data);
+ else
+ sb = get_sb_nodev(fstype, flags, data);
+
+ retval = PTR_ERR(sb);
+ if (IS_ERR(sb))
+ goto fs_out;
+
+ /* Something was mounted here while we slept */
+ while(d_mountpoint(nd->dentry) && follow_down(&nd->mnt, &nd->dentry))
+ ;
+
+ /* Refuse the same filesystem on the same mount point */
+ retval = -EBUSY;
+ if (nd->mnt->mnt_sb == sb && nd->mnt->mnt_root == nd->dentry)
+ goto fail;
+
+ retval = -ENOENT;
+ if (!nd->dentry->d_inode)
+ goto fail;
+ retval = -ENOTDIR;
+ if (!S_ISDIR(nd->dentry->d_inode->i_mode))
+ goto fail;
+ down(&nd->dentry->d_inode->i_zombie);
+ if (!IS_DEADDIR(nd->dentry->d_inode)) {
+ retval = -ENOMEM;
+ mnt = add_vfsmnt(nd, sb->s_root, name);
+ }
+ up(&nd->dentry->d_inode->i_zombie);
+ if (!mnt)
+ goto fail;
+ retval = 0;
+unlock_out:
+ up(&mount_sem);
+fs_out:
+ put_filesystem(fstype);
+ return retval;
+
+fail:
+ kill_super(sb);
+ goto unlock_out;
+}
+
static int copy_mount_options (const void *data, unsigned long *where)
{
int i;
@@ -1253,10 +1323,7 @@
long do_mount(char * dev_name, char * dir_name, char *type_page,
unsigned long flags, void *data_page)
{
- struct file_system_type * fstype;
struct nameidata nd;
- struct vfsmount *mnt = NULL;
- struct super_block *sb;
int retval = 0;

/* Discard magic */
@@ -1276,86 +1343,16 @@
if (retval)
return retval;

- /* just change the flags? - capabilities are checked in do_remount() */
- if (flags & MS_REMOUNT) {
- retval = do_remount(&nd, flags&~MS_REMOUNT, (char *)data_page);
- goto nd_out;
- }
-
- /* "mount --bind"? Equivalent to older "mount -t bind" */
- /* No capabilities? What if users do thousands of these? */
- if (flags & MS_BIND) {
+ if (flags & MS_REMOUNT)
+ retval = do_remount(&nd, flags&~MS_REMOUNT,
+ (char *)data_page);
+ else if (flags & MS_BIND)
retval = do_loopback(&nd, dev_name);
- goto nd_out;
- }
-
- /* For the rest we need the type */
-
- retval = -EINVAL;
- if (!type_page || !memchr(type_page, 0, PAGE_SIZE))
- goto nd_out;
-
- retval = -EPERM;
- /* for the rest we _really_ need capabilities... */
- if (!capable(CAP_SYS_ADMIN))
- goto nd_out;
-
- retval = -ENODEV;
- /* ... filesystem driver... */
- fstype = get_fs_type(type_page);
- if (!fstype)
- goto nd_out;
-
- /* get superblock, locks mount_sem on success */
- if (fstype->fs_flags & FS_NOMOUNT)
- sb = ERR_PTR(-EINVAL);
- else if (fstype->fs_flags & FS_REQUIRES_DEV)
- sb = get_sb_bdev(fstype, dev_name, flags, data_page);
- else if (fstype->fs_flags & FS_SINGLE)
- sb = get_sb_single(fstype, flags, data_page);
else
- sb = get_sb_nodev(fstype, flags, data_page);
-
- retval = PTR_ERR(sb);
- if (IS_ERR(sb))
- goto fs_out;
-
- /* Something was mounted here while we slept */
- while(d_mountpoint(nd.dentry) && follow_down(&nd.mnt, &nd.dentry))
- ;
-
- /* Refuse the same filesystem on the same mount point */
- retval = -EBUSY;
- if (nd.mnt && nd.mnt->mnt_sb == sb
- && nd.mnt->mnt_root == nd.dentry)
- goto fail;
-
- retval = -ENOENT;
- if (!nd.dentry->d_inode)
- goto fail;
- retval = -ENOTDIR;
- if (!S_ISDIR(nd.dentry->d_inode->i_mode))
- goto fail;
- down(&nd.dentry->d_inode->i_zombie);
- if (!IS_DEADDIR(nd.dentry->d_inode)) {
- retval = -ENOMEM;
- mnt = add_vfsmnt(&nd, sb->s_root, dev_name);
- }
- up(&nd.dentry->d_inode->i_zombie);
- if (!mnt)
- goto fail;
- retval = 0;
-unlock_out:
- up(&mount_sem);
-fs_out:
- put_filesystem(fstype);
-nd_out:
+ retval = do_add_mount(&nd, type_page, flags,
+ dev_name, data_page);
path_release(&nd);
return retval;
-
-fail:
- kill_super(sb);
- goto unlock_out;
}

asmlinkage long sys_mount(char * dev_name, char * dir_name, char * type,
-
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