Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp

Conflicts:
	litmus/sched_cedf.c

1 files changed, 455 insertions, 49 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 1776dbd8dc98..15634d4648d7 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -39,7 +39,9 @@
 #include <linux/miscdevice.h>
 #include <linux/magic.h>
 #include <linux/slab.h>
+#include <linux/cleancache.h>
 #include "compat.h"
+#include "delayed-inode.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -52,8 +54,95 @@
 #include "export.h"
 #include "compression.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/btrfs.h>
+
 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);
@@ -61,14 +150,19 @@ 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_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_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
-        Opt_discard, Opt_err,
+        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_enospc_debug, Opt_subvolrootid, Opt_defrag,
+        Opt_inode_cache, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -83,7 +177,9 @@ static match_table_t tokens = {
         {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"},
@@ -92,6 +188,13 @@ 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_enospc_debug, "enospc_debug"},
+        {Opt_subvolrootid, "subvolrootid=%d"},
+        {Opt_defrag, "autodefrag"},
+        {Opt_inode_cache, "inode_cache"},
         {Opt_err, NULL},
 };
 
@@ -106,6 +209,8 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
         char *p, *num, *orig;
         int intarg;
         int ret = 0;
+        char *compress_type;
+        bool compress_force = false;
 
         if (!options)
                 return 0;
@@ -133,6 +238,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                         break;
                 case Opt_subvol:
                 case Opt_subvolid:
+                case Opt_subvolrootid:
                 case Opt_device:
                         /*
                          * These are parsed by btrfs_parse_early_options
@@ -148,14 +254,32 @@ 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");
@@ -235,6 +359,28 @@ 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_inode_cache:
+                        printk(KERN_INFO "btrfs: enabling inode map caching\n");
+                        btrfs_set_opt(info->mount_opt, INODE_MAP_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_enospc_debug:
+                        btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
+                        break;
+                case Opt_defrag:
+                        printk(KERN_INFO "btrfs: enabling auto defrag");
+                        btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
+                        break;
                 case Opt_err:
                         printk(KERN_INFO "btrfs: unrecognized mount option "
                                "'%s'\n", p);
@@ -257,10 +403,10 @@ out:
  */
 static int btrfs_parse_early_options(const char *options, fmode_t flags,
                 void *holder, char **subvol_name, u64 *subvol_objectid,
-                struct btrfs_fs_devices **fs_devices)
+                u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
 {
         substring_t args[MAX_OPT_ARGS];
-        char *opts, *p;
+        char *opts, *orig, *p;
         int error = 0;
         int intarg;
 
@@ -274,6 +420,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
         opts = kstrdup(options, GFP_KERNEL);
         if (!opts)
                 return -ENOMEM;
+        orig = opts;
 
         while ((p = strsep(&opts, ",")) != NULL) {
                 int token;
@@ -297,6 +444,18 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
                                         *subvol_objectid = intarg;
                         }
                         break;
+                case Opt_subvolrootid:
+                        intarg = 0;
+                        error = match_int(&args[0], &intarg);
+                        if (!error) {
+                                /* we want the original fs_tree */
+                                if (!intarg)
+                                        *subvol_rootid =
+                                                BTRFS_FS_TREE_OBJECTID;
+                                else
+                                        *subvol_rootid = intarg;
+                        }
+                        break;
                 case Opt_device:
                         error = btrfs_scan_one_device(match_strdup(&args[0]),
                                         flags, holder, fs_devices);
@@ -309,7 +468,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
         }
 
  out_free_opts:
-        kfree(opts);
+        kfree(orig);
  out:
         /*
          * If no subvolume name is specified we use the default one.  Allocate
@@ -360,8 +519,10 @@ static struct dentry *get_default_root(struct super_block *sb,
          */
         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))
+        if (IS_ERR(di)) {
+                btrfs_free_path(path);
                 return ERR_CAST(di);
+        }
         if (!di) {
                 /*
                  * Ok the default dir item isn't there.  This is weird since
@@ -380,7 +541,7 @@ static struct dentry *get_default_root(struct super_block *sb,
 find_root:
         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
         if (IS_ERR(new_root))
-                return ERR_PTR(PTR_ERR(new_root));
+                return ERR_CAST(new_root);
 
         if (btrfs_root_refs(&new_root->root_item) == 0)
                 return ERR_PTR(-ENOENT);
@@ -436,7 +597,6 @@ static int btrfs_fill_super(struct super_block *sb,
 {
         struct inode *inode;
         struct dentry *root_dentry;
-        struct btrfs_super_block *disk_super;
         struct btrfs_root *tree_root;
         struct btrfs_key key;
         int err;
@@ -444,6 +604,7 @@ 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;
@@ -458,7 +619,6 @@ 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;
@@ -479,6 +639,7 @@ static int btrfs_fill_super(struct super_block *sb,
         sb->s_root = root_dentry;
 
         save_mount_options(sb, data);
+        cleancache_init_fs(sb);
         return 0;
 
 fail_close:
@@ -492,6 +653,8 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
         struct btrfs_root *root = btrfs_sb(sb);
         int ret;
 
+        trace_btrfs_sync_fs(wait);
+
         if (!wait) {
                 filemap_flush(root->fs_info->btree_inode->i_mapping);
                 return 0;
@@ -501,6 +664,8 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
         btrfs_wait_ordered_extents(root, 0, 0);
 
         trans = btrfs_start_transaction(root, 0);
+        if (IS_ERR(trans))
+                return PTR_ERR(trans);
         ret = btrfs_commit_transaction(trans, root);
         return ret;
 }
@@ -509,6 +674,7 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 {
         struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
         struct btrfs_fs_info *info = root->fs_info;
+        char *compress_type;
 
         if (btrfs_test_opt(root, DEGRADED))
                 seq_puts(seq, ",degraded");
@@ -527,8 +693,16 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
         if (info->thread_pool_size !=  min_t(unsigned long,
                                              num_online_cpus() + 2, 8))
                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
-        if (btrfs_test_opt(root, COMPRESS))
-                seq_puts(seq, ",compress");
+        if (btrfs_test_opt(root, COMPRESS)) {
+                if (info->compress_type == BTRFS_COMPRESS_ZLIB)
+                        compress_type = "zlib";
+                else
+                        compress_type = "lzo";
+                if (btrfs_test_opt(root, FORCE_COMPRESS))
+                        seq_printf(seq, ",compress-force=%s", compress_type);
+                else
+                        seq_printf(seq, ",compress=%s", compress_type);
+        }
         if (btrfs_test_opt(root, NOSSD))
                 seq_puts(seq, ",nossd");
         if (btrfs_test_opt(root, SSD_SPREAD))
@@ -543,46 +717,74 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_puts(seq, ",discard");
         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
                 seq_puts(seq, ",noacl");
+        if (btrfs_test_opt(root, SPACE_CACHE))
+                seq_puts(seq, ",space_cache");
+        if (btrfs_test_opt(root, CLEAR_CACHE))
+                seq_puts(seq, ",clear_cache");
+        if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
+                seq_puts(seq, ",user_subvol_rm_allowed");
+        if (btrfs_test_opt(root, ENOSPC_DEBUG))
+                seq_puts(seq, ",enospc_debug");
+        if (btrfs_test_opt(root, AUTO_DEFRAG))
+                seq_puts(seq, ",autodefrag");
+        if (btrfs_test_opt(root, INODE_MAP_CACHE))
+                seq_puts(seq, ",inode_cache");
         return 0;
 }
 
 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 *device_name, void *data)
 {
         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;
+        u64 subvol_rootid = 0;
         int error = 0;
-        int found = 0;
 
         if (!(flags & MS_RDONLY))
                 mode |= FMODE_WRITE;
 
         error = btrfs_parse_early_options(data, mode, fs_type,
                                           &subvol_name, &subvol_objectid,
-                                          &fs_devices);
+                                          &subvol_rootid, &fs_devices);
         if (error)
-                return error;
+                return ERR_PTR(error);
 
-        error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);
+        error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
         if (error)
                 goto error_free_subvol_name;
 
@@ -595,8 +797,24 @@ 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;
 
@@ -607,12 +825,13 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                         goto error_close_devices;
                 }
 
-                found = 1;
                 btrfs_close_devices(fs_devices);
+                kfree(fs_info);
+                kfree(tree_root);
         } else {
                 char b[BDEVNAME_SIZE];
 
-                s->s_flags = flags;
+                s->s_flags = flags | MS_NOSEC;
                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
                 error = btrfs_fill_super(s, fs_devices, data,
                                          flags & MS_SILENT ? 1 : 0);
@@ -625,51 +844,58 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
                 s->s_flags |= MS_ACTIVE;
         }
 
-        root = get_default_root(s, subvol_objectid);
-        if (IS_ERR(root)) {
-                error = PTR_ERR(root);
-                deactivate_locked_super(s);
-                goto error;
-        }
         /* if they gave us a subvolume name bind mount into that */
         if (strcmp(subvol_name, ".")) {
                 struct dentry *new_root;
+
+                root = get_default_root(s, subvol_rootid);
+                if (IS_ERR(root)) {
+                        error = PTR_ERR(root);
+                        deactivate_locked_super(s);
+                        goto error_free_subvol_name;
+                }
+
                 mutex_lock(&root->d_inode->i_mutex);
                 new_root = lookup_one_len(subvol_name, root,
                                       strlen(subvol_name));
                 mutex_unlock(&root->d_inode->i_mutex);
 
                 if (IS_ERR(new_root)) {
+                        dput(root);
                         deactivate_locked_super(s);
                         error = PTR_ERR(new_root);
-                        dput(root);
-                        goto error_close_devices;
+                        goto error_free_subvol_name;
                 }
                 if (!new_root->d_inode) {
                         dput(root);
                         dput(new_root);
                         deactivate_locked_super(s);
                         error = -ENXIO;
-                        goto error_close_devices;
+                        goto error_free_subvol_name;
                 }
                 dput(root);
                 root = new_root;
+        } else {
+                root = get_default_root(s, subvol_objectid);
+                if (IS_ERR(root)) {
+                        error = PTR_ERR(root);
+                        deactivate_locked_super(s);
+                        goto error_free_subvol_name;
+                }
         }
 
-        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);
-error:
-        return error;
+        return ERR_PTR(error);
 }
 
 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
@@ -709,6 +935,153 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
         return 0;
 }
 
+/* Used to sort the devices by max_avail(descending sort) */
+static int btrfs_cmp_device_free_bytes(const void *dev_info1,
+                                       const void *dev_info2)
+{
+        if (((struct btrfs_device_info *)dev_info1)->max_avail >
+            ((struct btrfs_device_info *)dev_info2)->max_avail)
+                return -1;
+        else if (((struct btrfs_device_info *)dev_info1)->max_avail <
+                 ((struct btrfs_device_info *)dev_info2)->max_avail)
+                return 1;
+        else
+        return 0;
+}
+
+/*
+ * sort the devices by max_avail, in which max free extent size of each device
+ * is stored.(Descending Sort)
+ */
+static inline void btrfs_descending_sort_devices(
+                                        struct btrfs_device_info *devices,
+                                        size_t nr_devices)
+{
+        sort(devices, nr_devices, sizeof(struct btrfs_device_info),
+             btrfs_cmp_device_free_bytes, NULL);
+}
+
+/*
+ * 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);
@@ -716,20 +1089,39 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
         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)
+        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 - (total_used >> bits);
-        buf->f_bavail = buf->f_bfree;
         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
@@ -746,7 +1138,7 @@ 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,
 };
@@ -815,6 +1207,7 @@ 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 = {
@@ -845,10 +1238,14 @@ 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;
@@ -857,10 +1254,14 @@ static int __init init_btrfs_fs(void)
         if (err)
                 goto free_extent_io;
 
-        err = btrfs_interface_init();
+        err = btrfs_delayed_inode_init();
         if (err)
                 goto free_extent_map;
 
+        err = btrfs_interface_init();
+        if (err)
+                goto free_delayed_inode;
+
         err = register_filesystem(&btrfs_fs_type);
         if (err)
                 goto unregister_ioctl;
@@ -870,12 +1271,16 @@ static int __init init_btrfs_fs(void)
 
 unregister_ioctl:
         btrfs_interface_exit();
+free_delayed_inode:
+        btrfs_delayed_inode_exit();
 free_extent_map:
         extent_map_exit();
 free_extent_io:
         extent_io_exit();
 free_cachep:
         btrfs_destroy_cachep();
+free_compress:
+        btrfs_exit_compress();
 free_sysfs:
         btrfs_exit_sysfs();
         return err;
@@ -884,13 +1289,14 @@ free_sysfs:
 static void __exit exit_btrfs_fs(void)
 {
         btrfs_destroy_cachep();
+        btrfs_delayed_inode_exit();
         extent_map_exit();
         extent_io_exit();
         btrfs_interface_exit();
         unregister_filesystem(&btrfs_fs_type);
         btrfs_exit_sysfs();
         btrfs_cleanup_fs_uuids();
-        btrfs_zlib_exit();
+        btrfs_exit_compress();
 }
 
 module_init(init_btrfs_fs)