Btrfs: Reinstate '-osubvol=.' option to mount entire tree

[safe/jmp/linux-2.6] / fs / btrfs / super.c

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b61ded7..f7b3eac 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -45,6 +45,8 @@
 #include "print-tree.h"
 #include "xattr.h"
 #include "volumes.h"
+#include "version.h"
+#include "export.h"
 
 #define BTRFS_SUPER_MAGIC 0x9123683E
 
@@ -67,7 +69,7 @@ static void btrfs_put_super (struct super_block * sb)
 enum {
        Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
        Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
-       Opt_ssd, Opt_thread_pool, Opt_err,
+       Opt_ssd, Opt_thread_pool, Opt_noacl,  Opt_err,
 };
 
 static match_table_t tokens = {
@@ -82,7 +84,8 @@ static match_table_t tokens = {
        {Opt_alloc_start, "alloc_start=%s"},
        {Opt_thread_pool, "thread_pool=%d"},
        {Opt_ssd, "ssd"},
-       {Opt_err, NULL}
+       {Opt_noacl, "noacl"},
+       {Opt_err, NULL},
 };
 
 u64 btrfs_parse_size(char *str)
@@ -214,6 +217,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                        info->alloc_start);
                        }
                        break;
+               case Opt_noacl:
+                       root->fs_info->sb->s_flags &= ~MS_POSIXACL;
+                       break;
                default:
                        break;
                }
@@ -298,8 +304,10 @@ static int btrfs_fill_super(struct super_block * sb,
        sb->s_maxbytes = MAX_LFS_FILESIZE;
        sb->s_magic = BTRFS_SUPER_MAGIC;
        sb->s_op = &btrfs_super_ops;
+       sb->s_export_op = &btrfs_export_ops;
        sb->s_xattr = btrfs_xattr_handlers;
        sb->s_time_gran = 1;
+       sb->s_flags |= MS_POSIXACL;
 
        tree_root = open_ctree(sb, fs_devices, (char *)data);
 
@@ -340,7 +348,6 @@ static int btrfs_fill_super(struct super_block * sb,
                goto fail_close;
 
        sb->s_root = root_dentry;
-       btrfs_transaction_queue_work(tree_root, HZ * 30);
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)
        save_mount_options(sb, data);
@@ -366,7 +373,6 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
                return 0;
        }
        btrfs_clean_old_snapshots(root);
-       btrfs_defrag_dirty_roots(root->fs_info);
        trans = btrfs_start_transaction(root, 1);
        ret = btrfs_commit_transaction(trans, root);
        sb->s_dirt = 0;
@@ -416,9 +422,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                goto error_free_subvol_name;
 
        bdev = fs_devices->latest_bdev;
-       btrfs_lock_volumes();
        s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
-       btrfs_unlock_volumes();
        if (IS_ERR(s))
                goto error_s;
 
@@ -447,19 +451,25 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                s->s_flags |= MS_ACTIVE;
        }
 
-       root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name));
-       if (IS_ERR(root)) {
-               up_write(&s->s_umount);
-               deactivate_super(s);
-               error = PTR_ERR(root);
-               goto error;
-       }
-       if (!root->d_inode) {
-               dput(root);
-               up_write(&s->s_umount);
-               deactivate_super(s);
-               error = -ENXIO;
-               goto error;
+       if (!strcmp(subvol_name, "."))
+               root = dget(s->s_root);
+       else {
+               mutex_lock(&s->s_root->d_inode->i_mutex);
+               root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name));
+               mutex_unlock(&s->s_root->d_inode->i_mutex);
+               if (IS_ERR(root)) {
+                       up_write(&s->s_umount);
+                       deactivate_super(s);
+                       error = PTR_ERR(root);
+                       goto error;
+               }
+               if (!root->d_inode) {
+                       dput(root);
+                       up_write(&s->s_umount);
+                       deactivate_super(s);
+                       error = -ENXIO;
+                       goto error;
+               }
        }
 
        mnt->mnt_sb = s;
@@ -483,6 +493,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
        struct btrfs_root *root = btrfs_sb(dentry->d_sb);
        struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
        int bits = dentry->d_sb->s_blocksize_bits;
+       __be32 *fsid = (__be32 *)root->fs_info->fsid;
 
        buf->f_namelen = BTRFS_NAME_LEN;
        buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
@@ -491,6 +502,15 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
        buf->f_bavail = buf->f_bfree;
        buf->f_bsize = dentry->d_sb->s_blocksize;
        buf->f_type = BTRFS_SUPER_MAGIC;
+       /* We treat it as constant endianness (it doesn't matter _which_)
+          because we want the fsid to come out the same whether mounted 
+          on a big-endian or little-endian host */
+       buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
+       buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
+       /* Mask in the root object ID too, to disambiguate subvols */
+       buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
+       buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
+
        return 0;
 }
 
@@ -530,13 +550,15 @@ out:
 static void btrfs_write_super_lockfs(struct super_block *sb)
 {
        struct btrfs_root *root = btrfs_sb(sb);
-       btrfs_transaction_flush_work(root);
+       mutex_lock(&root->fs_info->transaction_kthread_mutex);
+       mutex_lock(&root->fs_info->cleaner_mutex);
 }
 
 static void btrfs_unlockfs(struct super_block *sb)
 {
        struct btrfs_root *root = btrfs_sb(sb);
-       btrfs_transaction_queue_work(root, HZ * 30);
+       mutex_unlock(&root->fs_info->cleaner_mutex);
+       mutex_unlock(&root->fs_info->transaction_kthread_mutex);
 }
 
 static struct super_operations btrfs_super_ops = {
@@ -589,10 +611,9 @@ static int __init init_btrfs_fs(void)
        if (err)
                return err;
 
-       btrfs_init_transaction_sys();
        err = btrfs_init_cachep();
        if (err)
-               goto free_transaction_sys;
+               goto free_sysfs;
 
        err = extent_io_init();
        if (err)
@@ -608,6 +629,8 @@ static int __init init_btrfs_fs(void)
        err = register_filesystem(&btrfs_fs_type);
        if (err)
                goto unregister_ioctl;
+
+       printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
        return 0;
 
 unregister_ioctl:
@@ -618,15 +641,13 @@ free_extent_io:
        extent_io_exit();
 free_cachep:
        btrfs_destroy_cachep();
-free_transaction_sys:
-       btrfs_exit_transaction_sys();
+free_sysfs:
        btrfs_exit_sysfs();
        return err;
 }
 
 static void __exit exit_btrfs_fs(void)
 {
-       btrfs_exit_transaction_sys();
        btrfs_destroy_cachep();
        extent_map_exit();
        extent_io_exit();