1 files changed, 498 insertions, 101 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8a1ea6e64575..b2130c46fdb5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -38,6 +38,7 @@
 #include <linux/namei.h>
 #include <linux/miscdevice.h>
 #include <linux/magic.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -53,6 +54,90 @@
 
 static const struct super_operations btrfs_super_ops;
 
+static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
+                                      char nbuf[16])
+{
+        char *errstr = NULL;
+
+        switch (errno) {
+        case -EIO:
+                errstr = "IO failure";
+                break;
+        case -ENOMEM:
+                errstr = "Out of memory";
+                break;
+        case -EROFS:
+                errstr = "Readonly filesystem";
+                break;
+        default:
+                if (nbuf) {
+                        if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
+                                errstr = nbuf;
+                }
+                break;
+        }
+
+        return errstr;
+}
+
+static void __save_error_info(struct btrfs_fs_info *fs_info)
+{
+        /*
+         * today we only save the error info into ram.  Long term we'll
+         * also send it down to the disk
+         */
+        fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
+}
+
+/* NOTE:
+ *      We move write_super stuff at umount in order to avoid deadlock
+ *      for umount hold all lock.
+ */
+static void save_error_info(struct btrfs_fs_info *fs_info)
+{
+        __save_error_info(fs_info);
+}
+
+/* btrfs handle error by forcing the filesystem readonly */
+static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
+{
+        struct super_block *sb = fs_info->sb;
+
+        if (sb->s_flags & MS_RDONLY)
+                return;
+
+        if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+                sb->s_flags |= MS_RDONLY;
+                printk(KERN_INFO "btrfs is forced readonly\n");
+        }
+}
+
+/*
+ * __btrfs_std_error decodes expected errors from the caller and
+ * invokes the approciate error response.
+ */
+void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
+                     unsigned int line, int errno)
+{
+        struct super_block *sb = fs_info->sb;
+        char nbuf[16];
+        const char *errstr;
+
+        /*
+         * Special case: if the error is EROFS, and we're already
+         * under MS_RDONLY, then it is safe here.
+         */
+        if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
+                return;
+
+        errstr = btrfs_decode_error(fs_info, errno, nbuf);
+        printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
+                sb->s_id, function, line, errstr);
+        save_error_info(fs_info);
+
+        btrfs_handle_error(fs_info);
+}
+
 static void btrfs_put_super(struct super_block *sb)
 {
         struct btrfs_root *root = btrfs_sb(sb);
@@ -60,30 +145,34 @@ static void btrfs_put_super(struct super_block *sb)
 
         ret = close_ctree(root);
         sb->s_fs_info = NULL;
+
+        (void)ret; /* FIXME: need to fix VFS to return error? */
 }
 
 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_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl,
-        Opt_compress, Opt_compress_force, Opt_notreelog, Opt_ratio,
-        Opt_flushoncommit,
-        Opt_discard, Opt_err,
+        Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
+        Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
+        Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
+        Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
+        Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
+        Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, Opt_err,
 };
 
 static match_table_t tokens = {
         {Opt_degraded, "degraded"},
         {Opt_subvol, "subvol=%s"},
+        {Opt_subvolid, "subvolid=%d"},
         {Opt_device, "device=%s"},
         {Opt_nodatasum, "nodatasum"},
         {Opt_nodatacow, "nodatacow"},
         {Opt_nobarrier, "nobarrier"},
-        {Opt_max_extent, "max_extent=%s"},
         {Opt_max_inline, "max_inline=%s"},
         {Opt_alloc_start, "alloc_start=%s"},
         {Opt_thread_pool, "thread_pool=%d"},
         {Opt_compress, "compress"},
+        {Opt_compress_type, "compress=%s"},
         {Opt_compress_force, "compress-force"},
+        {Opt_compress_force_type, "compress-force=%s"},
         {Opt_ssd, "ssd"},
         {Opt_ssd_spread, "ssd_spread"},
         {Opt_nossd, "nossd"},
@@ -92,34 +181,12 @@ static match_table_t tokens = {
         {Opt_flushoncommit, "flushoncommit"},
         {Opt_ratio, "metadata_ratio=%d"},
         {Opt_discard, "discard"},
+        {Opt_space_cache, "space_cache"},
+        {Opt_clear_cache, "clear_cache"},
+        {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
         {Opt_err, NULL},
 };
 
-u64 btrfs_parse_size(char *str)
-{
-        u64 res;
-        int mult = 1;
-        char *end;
-        char last;
-
-        res = simple_strtoul(str, &end, 10);
-
-        last = end[0];
-        if (isalpha(last)) {
-                last = tolower(last);
-                switch (last) {
-                case 'g':
-                        mult *= 1024;
-                case 'm':
-                        mult *= 1024;
-                case 'k':
-                        mult *= 1024;
-                }
-                res = res * mult;
-        }
-        return res;
-}
-
 /*
  * Regular mount options parser.  Everything that is needed only when
  * reading in a new superblock is parsed here.
@@ -128,9 +195,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 {
         struct btrfs_fs_info *info = root->fs_info;
         substring_t args[MAX_OPT_ARGS];
-        char *p, *num;
+        char *p, *num, *orig;
         int intarg;
         int ret = 0;
+        char *compress_type;
+        bool compress_force = false;
 
         if (!options)
                 return 0;
@@ -143,6 +212,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
         if (!options)
                 return -ENOMEM;
 
+        orig = options;
 
         while ((p = strsep(&options, ",")) != NULL) {
                 int token;
@@ -156,6 +226,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                         btrfs_set_opt(info->mount_opt, DEGRADED);
                         break;
                 case Opt_subvol:
+                case Opt_subvolid:
                 case Opt_device:
                         /*
                          * These are parsed by btrfs_parse_early_options
@@ -171,14 +242,32 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                         btrfs_set_opt(info->mount_opt, NODATACOW);
                         btrfs_set_opt(info->mount_opt, NODATASUM);
                         break;
-                case Opt_compress:
-                        printk(KERN_INFO "btrfs: use compression\n");
-                        btrfs_set_opt(info->mount_opt, COMPRESS);
-                        break;
                 case Opt_compress_force:
-                        printk(KERN_INFO "btrfs: forcing compression\n");
-                        btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+                case Opt_compress_force_type:
+                        compress_force = true;
+                case Opt_compress:
+                case Opt_compress_type:
+                        if (token == Opt_compress ||
+                            token == Opt_compress_force ||
+                            strcmp(args[0].from, "zlib") == 0) {
+                                compress_type = "zlib";
+                                info->compress_type = BTRFS_COMPRESS_ZLIB;
+                        } else if (strcmp(args[0].from, "lzo") == 0) {
+                                compress_type = "lzo";
+                                info->compress_type = BTRFS_COMPRESS_LZO;
+                        } else {
+                                ret = -EINVAL;
+                                goto out;
+                        }
+
                         btrfs_set_opt(info->mount_opt, COMPRESS);
+                        if (compress_force) {
+                                btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+                                pr_info("btrfs: force %s compression\n",
+                                        compress_type);
+                        } else
+                                pr_info("btrfs: use %s compression\n",
+                                        compress_type);
                         break;
                 case Opt_ssd:
                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
@@ -210,22 +299,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                        info->thread_pool_size);
                         }
                         break;
-                case Opt_max_extent:
-                        num = match_strdup(&args[0]);
-                        if (num) {
-                                info->max_extent = btrfs_parse_size(num);
-                                kfree(num);
-
-                                info->max_extent = max_t(u64,
-                                        info->max_extent, root->sectorsize);
-                                printk(KERN_INFO "btrfs: max_extent at %llu\n",
-                                       (unsigned long long)info->max_extent);
-                        }
-                        break;
                 case Opt_max_inline:
                         num = match_strdup(&args[0]);
                         if (num) {
-                                info->max_inline = btrfs_parse_size(num);
+                                info->max_inline = memparse(num, NULL);
                                 kfree(num);
 
                                 if (info->max_inline) {
@@ -240,7 +317,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                 case Opt_alloc_start:
                         num = match_strdup(&args[0]);
                         if (num) {
-                                info->alloc_start = btrfs_parse_size(num);
+                                info->alloc_start = memparse(num, NULL);
                                 kfree(num);
                                 printk(KERN_INFO
                                         "btrfs: allocations start at %llu\n",
@@ -270,6 +347,17 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                 case Opt_discard:
                         btrfs_set_opt(info->mount_opt, DISCARD);
                         break;
+                case Opt_space_cache:
+                        printk(KERN_INFO "btrfs: enabling disk space caching\n");
+                        btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+                        break;
+                case Opt_clear_cache:
+                        printk(KERN_INFO "btrfs: force clearing of disk cache\n");
+                        btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
+                        break;
+                case Opt_user_subvol_rm_allowed:
+                        btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
+                        break;
                 case Opt_err:
                         printk(KERN_INFO "btrfs: unrecognized mount option "
                                "'%s'\n", p);
@@ -280,7 +368,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                 }
         }
 out:
-        kfree(options);
+        kfree(orig);
         return ret;
 }
 
@@ -291,12 +379,13 @@ out:
  * only when we need to allocate a new super block.
  */
 static int btrfs_parse_early_options(const char *options, fmode_t flags,
-                void *holder, char **subvol_name,
+                void *holder, char **subvol_name, u64 *subvol_objectid,
                 struct btrfs_fs_devices **fs_devices)
 {
         substring_t args[MAX_OPT_ARGS];
         char *opts, *p;
         int error = 0;
+        int intarg;
 
         if (!options)
                 goto out;
@@ -319,6 +408,18 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
                 case Opt_subvol:
                         *subvol_name = match_strdup(&args[0]);
                         break;
+                case Opt_subvolid:
+                        intarg = 0;
+                        error = match_int(&args[0], &intarg);
+                        if (!error) {
+                                /* we want the original fs_tree */
+                                if (!intarg)
+                                        *subvol_objectid =
+                                                BTRFS_FS_TREE_OBJECTID;
+                                else
+                                        *subvol_objectid = intarg;
+                        }
+                        break;
                 case Opt_device:
                         error = btrfs_scan_one_device(match_strdup(&args[0]),
                                         flags, holder, fs_devices);
@@ -346,13 +447,118 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
         return error;
 }
 
+static struct dentry *get_default_root(struct super_block *sb,
+                                       u64 subvol_objectid)
+{
+        struct btrfs_root *root = sb->s_fs_info;
+        struct btrfs_root *new_root;
+        struct btrfs_dir_item *di;
+        struct btrfs_path *path;
+        struct btrfs_key location;
+        struct inode *inode;
+        struct dentry *dentry;
+        u64 dir_id;
+        int new = 0;
+
+        /*
+         * We have a specific subvol we want to mount, just setup location and
+         * go look up the root.
+         */
+        if (subvol_objectid) {
+                location.objectid = subvol_objectid;
+                location.type = BTRFS_ROOT_ITEM_KEY;
+                location.offset = (u64)-1;
+                goto find_root;
+        }
+
+        path = btrfs_alloc_path();
+        if (!path)
+                return ERR_PTR(-ENOMEM);
+        path->leave_spinning = 1;
+
+        /*
+         * Find the "default" dir item which points to the root item that we
+         * will mount by default if we haven't been given a specific subvolume
+         * to mount.
+         */
+        dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
+        di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
+        if (IS_ERR(di))
+                return ERR_CAST(di);
+        if (!di) {
+                /*
+                 * Ok the default dir item isn't there.  This is weird since
+                 * it's always been there, but don't freak out, just try and
+                 * mount to root most subvolume.
+                 */
+                btrfs_free_path(path);
+                dir_id = BTRFS_FIRST_FREE_OBJECTID;
+                new_root = root->fs_info->fs_root;
+                goto setup_root;
+        }
+
+        btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+        btrfs_free_path(path);
+
+find_root:
+        new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
+        if (IS_ERR(new_root))
+                return ERR_CAST(new_root);
+
+        if (btrfs_root_refs(&new_root->root_item) == 0)
+                return ERR_PTR(-ENOENT);
+
+        dir_id = btrfs_root_dirid(&new_root->root_item);
+setup_root:
+        location.objectid = dir_id;
+        location.type = BTRFS_INODE_ITEM_KEY;
+        location.offset = 0;
+
+        inode = btrfs_iget(sb, &location, new_root, &new);
+        if (IS_ERR(inode))
+                return ERR_CAST(inode);
+
+        /*
+         * If we're just mounting the root most subvol put the inode and return
+         * a reference to the dentry.  We will have already gotten a reference
+         * to the inode in btrfs_fill_super so we're good to go.
+         */
+        if (!new && sb->s_root->d_inode == inode) {
+                iput(inode);
+                return dget(sb->s_root);
+        }
+
+        if (new) {
+                const struct qstr name = { .name = "/", .len = 1 };
+
+                /*
+                 * New inode, we need to make the dentry a sibling of s_root so
+                 * everything gets cleaned up properly on unmount.
+                 */
+                dentry = d_alloc(sb->s_root, &name);
+                if (!dentry) {
+                        iput(inode);
+                        return ERR_PTR(-ENOMEM);
+                }
+                d_splice_alias(inode, dentry);
+        } else {
+                /*
+                 * We found the inode in cache, just find a dentry for it and
+                 * put the reference to the inode we just got.
+                 */
+                dentry = d_find_alias(inode);
+                iput(inode);
+        }
+
+        return dentry;
+}
+
 static int btrfs_fill_super(struct super_block *sb,
                             struct btrfs_fs_devices *fs_devices,
                             void *data, int silent)
 {
         struct inode *inode;
         struct dentry *root_dentry;
-        struct btrfs_super_block *disk_super;
         struct btrfs_root *tree_root;
         struct btrfs_key key;
         int err;
@@ -360,6 +566,7 @@ 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_d_op = &btrfs_dentry_operations;
         sb->s_export_op = &btrfs_export_ops;
         sb->s_xattr = btrfs_xattr_handlers;
         sb->s_time_gran = 1;
@@ -374,12 +581,11 @@ static int btrfs_fill_super(struct super_block *sb,
                 return PTR_ERR(tree_root);
         }
         sb->s_fs_info = tree_root;
-        disk_super = &tree_root->fs_info->super_copy;
 
         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
         key.type = BTRFS_INODE_ITEM_KEY;
         key.offset = 0;
-        inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root);
+        inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
         if (IS_ERR(inode)) {
                 err = PTR_ERR(inode);
                 goto fail_close;
@@ -391,12 +597,6 @@ static int btrfs_fill_super(struct super_block *sb,
                 err = -ENOMEM;
                 goto fail_close;
         }
-#if 0
-        /* this does the super kobj at the same time */
-        err = btrfs_sysfs_add_super(tree_root->fs_info);
-        if (err)
-                goto fail_close;
-#endif
 
         sb->s_root = root_dentry;
 
@@ -422,7 +622,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
         btrfs_start_delalloc_inodes(root, 0);
         btrfs_wait_ordered_extents(root, 0, 0);
 
-        trans = btrfs_start_transaction(root, 1);
+        trans = btrfs_start_transaction(root, 0);
         ret = btrfs_commit_transaction(trans, root);
         return ret;
 }
@@ -440,9 +640,6 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_puts(seq, ",nodatacow");
         if (btrfs_test_opt(root, NOBARRIER))
                 seq_puts(seq, ",nobarrier");
-        if (info->max_extent != (u64)-1)
-                seq_printf(seq, ",max_extent=%llu",
-                           (unsigned long long)info->max_extent);
         if (info->max_inline != 8192 * 1024)
                 seq_printf(seq, ",max_inline=%llu",
                            (unsigned long long)info->max_inline);
@@ -473,36 +670,54 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 
 static int btrfs_test_super(struct super_block *s, void *data)
 {
-        struct btrfs_fs_devices *test_fs_devices = data;
+        struct btrfs_root *test_root = data;
         struct btrfs_root *root = btrfs_sb(s);
 
-        return root->fs_info->fs_devices == test_fs_devices;
+        /*
+         * If this super block is going away, return false as it
+         * can't match as an existing super block.
+         */
+        if (!atomic_read(&s->s_active))
+                return 0;
+        return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
+}
+
+static int btrfs_set_super(struct super_block *s, void *data)
+{
+        s->s_fs_info = data;
+
+        return set_anon_super(s, data);
 }
 
+
 /*
  * Find a superblock for the given device / mount point.
  *
  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
  *        for multiple device setup.  Make sure to keep it in sync.
  */
-static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
-                const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
+                const char *dev_name, void *data)
 {
-        char *subvol_name = NULL;
         struct block_device *bdev = NULL;
         struct super_block *s;
         struct dentry *root;
         struct btrfs_fs_devices *fs_devices = NULL;
+        struct btrfs_root *tree_root = NULL;
+        struct btrfs_fs_info *fs_info = NULL;
         fmode_t mode = FMODE_READ;
+        char *subvol_name = NULL;
+        u64 subvol_objectid = 0;
         int error = 0;
 
         if (!(flags & MS_RDONLY))
                 mode |= FMODE_WRITE;
 
         error = btrfs_parse_early_options(data, mode, fs_type,
-                                          &subvol_name, &fs_devices);
+                                          &subvol_name, &subvol_objectid,
+                                          &fs_devices);
         if (error)
-                return error;
+                return ERR_PTR(error);
 
         error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);
         if (error)
@@ -517,8 +732,24 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                 goto error_close_devices;
         }
 
+        /*
+         * Setup a dummy root and fs_info for test/set super.  This is because
+         * we don't actually fill this stuff out until open_ctree, but we need
+         * it for searching for existing supers, so this lets us do that and
+         * then open_ctree will properly initialize everything later.
+         */
+        fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
+        tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
+        if (!fs_info || !tree_root) {
+                error = -ENOMEM;
+                goto error_close_devices;
+        }
+        fs_info->tree_root = tree_root;
+        fs_info->fs_devices = fs_devices;
+        tree_root->fs_info = fs_info;
+
         bdev = fs_devices->latest_bdev;
-        s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
+        s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
         if (IS_ERR(s))
                 goto error_s;
 
@@ -546,40 +777,49 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                 s->s_flags |= MS_ACTIVE;
         }
 
-        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,
+        root = get_default_root(s, subvol_objectid);
+        if (IS_ERR(root)) {
+                error = PTR_ERR(root);
+                deactivate_locked_super(s);
+                goto error_free_subvol_name;
+        }
+        /* if they gave us a subvolume name bind mount into that */
+        if (strcmp(subvol_name, ".")) {
+                struct dentry *new_root;
+                mutex_lock(&root->d_inode->i_mutex);
+                new_root = lookup_one_len(subvol_name, root,
                                       strlen(subvol_name));
-                mutex_unlock(&s->s_root->d_inode->i_mutex);
+                mutex_unlock(&root->d_inode->i_mutex);
 
-                if (IS_ERR(root)) {
+                if (IS_ERR(new_root)) {
+                        dput(root);
                         deactivate_locked_super(s);
-                        error = PTR_ERR(root);
+                        error = PTR_ERR(new_root);
                         goto error_free_subvol_name;
                 }
-                if (!root->d_inode) {
+                if (!new_root->d_inode) {
                         dput(root);
+                        dput(new_root);
                         deactivate_locked_super(s);
                         error = -ENXIO;
                         goto error_free_subvol_name;
                 }
+                dput(root);
+                root = new_root;
         }
 
-        mnt->mnt_sb = s;
-        mnt->mnt_root = root;
-
         kfree(subvol_name);
-        return 0;
+        return root;
 
 error_s:
         error = PTR_ERR(s);
 error_close_devices:
         btrfs_close_devices(fs_devices);
+        kfree(fs_info);
+        kfree(tree_root);
 error_free_subvol_name:
         kfree(subvol_name);
-        return error;
+        return ERR_PTR(error);
 }
 
 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
@@ -606,11 +846,11 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
                 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
                         return -EINVAL;
 
-                /* recover relocation */
-                ret = btrfs_recover_relocation(root);
+                ret = btrfs_cleanup_fs_roots(root->fs_info);
                 WARN_ON(ret);
 
-                ret = btrfs_cleanup_fs_roots(root->fs_info);
+                /* recover relocation */
+                ret = btrfs_recover_relocation(root);
                 WARN_ON(ret);
 
                 sb->s_flags &= ~MS_RDONLY;
@@ -619,20 +859,167 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
         return 0;
 }
 
+/*
+ * The helper to calc the free space on the devices that can be used to store
+ * file data.
+ */
+static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
+{
+        struct btrfs_fs_info *fs_info = root->fs_info;
+        struct btrfs_device_info *devices_info;
+        struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+        struct btrfs_device *device;
+        u64 skip_space;
+        u64 type;
+        u64 avail_space;
+        u64 used_space;
+        u64 min_stripe_size;
+        int min_stripes = 1;
+        int i = 0, nr_devices;
+        int ret;
+
+        nr_devices = fs_info->fs_devices->rw_devices;
+        BUG_ON(!nr_devices);
+
+        devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
+                               GFP_NOFS);
+        if (!devices_info)
+                return -ENOMEM;
+
+        /* calc min stripe number for data space alloction */
+        type = btrfs_get_alloc_profile(root, 1);
+        if (type & BTRFS_BLOCK_GROUP_RAID0)
+                min_stripes = 2;
+        else if (type & BTRFS_BLOCK_GROUP_RAID1)
+                min_stripes = 2;
+        else if (type & BTRFS_BLOCK_GROUP_RAID10)
+                min_stripes = 4;
+
+        if (type & BTRFS_BLOCK_GROUP_DUP)
+                min_stripe_size = 2 * BTRFS_STRIPE_LEN;
+        else
+                min_stripe_size = BTRFS_STRIPE_LEN;
+
+        list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
+                if (!device->in_fs_metadata)
+                        continue;
+
+                avail_space = device->total_bytes - device->bytes_used;
+
+                /* align with stripe_len */
+                do_div(avail_space, BTRFS_STRIPE_LEN);
+                avail_space *= BTRFS_STRIPE_LEN;
+
+                /*
+                 * In order to avoid overwritting the superblock on the drive,
+                 * btrfs starts at an offset of at least 1MB when doing chunk
+                 * allocation.
+                 */
+                skip_space = 1024 * 1024;
+
+                /* user can set the offset in fs_info->alloc_start. */
+                if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
+                    device->total_bytes)
+                        skip_space = max(fs_info->alloc_start, skip_space);
+
+                /*
+                 * btrfs can not use the free space in [0, skip_space - 1],
+                 * we must subtract it from the total. In order to implement
+                 * it, we account the used space in this range first.
+                 */
+                ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
+                                                     &used_space);
+                if (ret) {
+                        kfree(devices_info);
+                        return ret;
+                }
+
+                /* calc the free space in [0, skip_space - 1] */
+                skip_space -= used_space;
+
+                /*
+                 * we can use the free space in [0, skip_space - 1], subtract
+                 * it from the total.
+                 */
+                if (avail_space && avail_space >= skip_space)
+                        avail_space -= skip_space;
+                else
+                        avail_space = 0;
+
+                if (avail_space < min_stripe_size)
+                        continue;
+
+                devices_info[i].dev = device;
+                devices_info[i].max_avail = avail_space;
+
+                i++;
+        }
+
+        nr_devices = i;
+
+        btrfs_descending_sort_devices(devices_info, nr_devices);
+
+        i = nr_devices - 1;
+        avail_space = 0;
+        while (nr_devices >= min_stripes) {
+                if (devices_info[i].max_avail >= min_stripe_size) {
+                        int j;
+                        u64 alloc_size;
+
+                        avail_space += devices_info[i].max_avail * min_stripes;
+                        alloc_size = devices_info[i].max_avail;
+                        for (j = i + 1 - min_stripes; j <= i; j++)
+                                devices_info[j].max_avail -= alloc_size;
+                }
+                i--;
+                nr_devices--;
+        }
+
+        kfree(devices_info);
+        *free_bytes = avail_space;
+        return 0;
+}
+
 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;
+        struct list_head *head = &root->fs_info->space_info;
+        struct btrfs_space_info *found;
+        u64 total_used = 0;
+        u64 total_free_data = 0;
         int bits = dentry->d_sb->s_blocksize_bits;
         __be32 *fsid = (__be32 *)root->fs_info->fsid;
+        int ret;
+
+        /* holding chunk_muext to avoid allocating new chunks */
+        mutex_lock(&root->fs_info->chunk_mutex);
+        rcu_read_lock();
+        list_for_each_entry_rcu(found, head, list) {
+                if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
+                        total_free_data += found->disk_total - found->disk_used;
+                        total_free_data -=
+                                btrfs_account_ro_block_groups_free_space(found);
+                }
+
+                total_used += found->disk_used;
+        }
+        rcu_read_unlock();
 
         buf->f_namelen = BTRFS_NAME_LEN;
         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
-        buf->f_bfree = buf->f_blocks -
-                (btrfs_super_bytes_used(disk_super) >> bits);
-        buf->f_bavail = buf->f_bfree;
+        buf->f_bfree = buf->f_blocks - (total_used >> bits);
         buf->f_bsize = dentry->d_sb->s_blocksize;
         buf->f_type = BTRFS_SUPER_MAGIC;
+        buf->f_bavail = total_free_data;
+        ret = btrfs_calc_avail_data_space(root, &total_free_data);
+        if (ret) {
+                mutex_unlock(&root->fs_info->chunk_mutex);
+                return ret;
+        }
+        buf->f_bavail += total_free_data;
+        buf->f_bavail = buf->f_bavail >> bits;
+        mutex_unlock(&root->fs_info->chunk_mutex);
 
         /* We treat it as constant endianness (it doesn't matter _which_)
            because we want the fsid to come out the same whether mounted
@@ -649,7 +1036,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 static struct file_system_type btrfs_fs_type = {
         .owner          = THIS_MODULE,
         .name           = "btrfs",
-        .get_sb         = btrfs_get_sb,
+        .mount          = btrfs_mount,
         .kill_sb        = kill_anon_super,
         .fs_flags       = FS_REQUIRES_DEV,
 };
@@ -700,7 +1087,7 @@ static int btrfs_unfreeze(struct super_block *sb)
 
 static const struct super_operations btrfs_super_ops = {
         .drop_inode     = btrfs_drop_inode,
-        .delete_inode   = btrfs_delete_inode,
+        .evict_inode    = btrfs_evict_inode,
         .put_super      = btrfs_put_super,
         .sync_fs        = btrfs_sync_fs,
         .show_options   = btrfs_show_options,
@@ -718,14 +1105,18 @@ static const struct file_operations btrfs_ctl_fops = {
         .unlocked_ioctl  = btrfs_control_ioctl,
         .compat_ioctl = btrfs_control_ioctl,
         .owner   = THIS_MODULE,
+        .llseek = noop_llseek,
 };
 
 static struct miscdevice btrfs_misc = {
-        .minor          = MISC_DYNAMIC_MINOR,
+        .minor          = BTRFS_MINOR,
         .name           = "btrfs-control",
         .fops           = &btrfs_ctl_fops
 };
 
+MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
+MODULE_ALIAS("devname:btrfs-control");
+
 static int btrfs_interface_init(void)
 {
         return misc_register(&btrfs_misc);
@@ -745,10 +1136,14 @@ static int __init init_btrfs_fs(void)
         if (err)
                 return err;
 
-        err = btrfs_init_cachep();
+        err = btrfs_init_compress();
         if (err)
                 goto free_sysfs;
 
+        err = btrfs_init_cachep();
+        if (err)
+                goto free_compress;
+
         err = extent_io_init();
         if (err)
                 goto free_cachep;
@@ -776,6 +1171,8 @@ free_extent_io:
         extent_io_exit();
 free_cachep:
         btrfs_destroy_cachep();
+free_compress:
+        btrfs_exit_compress();
 free_sysfs:
         btrfs_exit_sysfs();
         return err;
@@ -790,7 +1187,7 @@ static void __exit exit_btrfs_fs(void)
         unregister_filesystem(&btrfs_fs_type);
         btrfs_exit_sysfs();
         btrfs_cleanup_fs_uuids();
-        btrfs_zlib_exit();
+        btrfs_exit_compress();
 }
 
 module_init(init_btrfs_fs)