Btrfs: add better -ENOSPC handling

This is a step in the direction of better -ENOSPC handling.  Instead of
checking the global bytes counter we check the space_info bytes counters to
make sure we have enough space.

If we don't we go ahead and try to allocate a new chunk, and then if that fails
we return -ENOSPC.  This patch adds two counters to btrfs_space_info,
bytes_delalloc and bytes_may_use.

bytes_delalloc account for extents we've actually setup for delalloc and will
be allocated at some point down the line. 

bytes_may_use is to keep track of how many bytes we may use for delalloc at
some point.  When we actually set the extent_bit for the delalloc bytes we
subtract the reserved bytes from the bytes_may_use counter.  This keeps us from
not actually being able to allocate space for any delalloc bytes.

Signed-off-by: Josef Bacik <jbacik@redhat.com>

6 files changed, 271 insertions, 76 deletions

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index a8c9693b75ac..72677ce2b74f 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -66,6 +66,9 @@ struct btrfs_inode {
          */
         struct list_head delalloc_inodes;
 
+        /* the space_info for where this inode's data allocations are done */
+        struct btrfs_space_info *space_info;
+
         /* full 64 bit generation number, struct vfs_inode doesn't have a big
          * enough field for this.
          */
@@ -94,6 +97,11 @@ struct btrfs_inode {
          */
         u64 delalloc_bytes;
 
+        /* total number of bytes that may be used for this inode for
+         * delalloc
+         */
+        u64 reserved_bytes;
+
         /*
          * the size of the file stored in the metadata on disk.  data=ordered
          * means the in-memory i_size might be larger than the size on disk
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 766b31ae3186..82491ba8fa40 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -596,13 +596,27 @@ struct btrfs_block_group_item {
 
 struct btrfs_space_info {
         u64 flags;
-        u64 total_bytes;
-        u64 bytes_used;
-        u64 bytes_pinned;
-        u64 bytes_reserved;
-        u64 bytes_readonly;
-        int full;
-        int force_alloc;
+
+        u64 total_bytes;        /* total bytes in the space */
+        u64 bytes_used;         /* total bytes used on disk */
+        u64 bytes_pinned;       /* total bytes pinned, will be freed when the
+                                   transaction finishes */
+        u64 bytes_reserved;     /* total bytes the allocator has reserved for
+                                   current allocations */
+        u64 bytes_readonly;     /* total bytes that are read only */
+
+        /* delalloc accounting */
+        u64 bytes_delalloc;     /* number of bytes reserved for allocation,
+                                   this space is not necessarily reserved yet
+                                   by the allocator */
+        u64 bytes_may_use;      /* number of bytes that may be used for
+                                   delalloc */
+
+        int full;               /* indicates that we cannot allocate any more
+                                   chunks for this space */
+        int force_alloc;        /* set if we need to force a chunk alloc for
+                                   this space */
+
         struct list_head list;
 
         /* for block groups in our same type */
@@ -1782,6 +1796,16 @@ int btrfs_add_dead_reloc_root(struct btrfs_root *root);
 int btrfs_cleanup_reloc_trees(struct btrfs_root *root);
 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len);
 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
+void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *ionde);
+int btrfs_check_metadata_free_space(struct btrfs_root *root);
+int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
+                                u64 bytes);
+void btrfs_free_reserved_data_space(struct btrfs_root *root,
+                                    struct inode *inode, u64 bytes);
+void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
+                                 u64 bytes);
+void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
+                              u64 bytes);
 /* ctree.c */
 int btrfs_previous_item(struct btrfs_root *root,
                         struct btrfs_path *path, u64 min_objectid,
@@ -2027,8 +2051,6 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
 unsigned long btrfs_force_ra(struct address_space *mapping,
                               struct file_ra_state *ra, struct file *file,
                               pgoff_t offset, pgoff_t last_index);
-int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
-                           int for_del);
 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page);
 int btrfs_readpage(struct file *file, struct page *page);
 void btrfs_delete_inode(struct inode *inode);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0a5d796c9f7e..e11875e97c2f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -60,6 +60,10 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                               u64 bytenr, u64 num_bytes, int alloc,
                               int mark_free);
 
+static int do_chunk_alloc(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *extent_root, u64 alloc_bytes,
+                          u64 flags, int force);
+
 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 {
         return (cache->flags & bits) == bits;
@@ -1909,6 +1913,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
         found->bytes_pinned = 0;
         found->bytes_reserved = 0;
         found->bytes_readonly = 0;
+        found->bytes_delalloc = 0;
         found->full = 0;
         found->force_alloc = 0;
         *space_info = found;
@@ -1972,6 +1977,196 @@ u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
         return flags;
 }
 
+static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data)
+{
+        struct btrfs_fs_info *info = root->fs_info;
+        u64 alloc_profile;
+
+        if (data) {
+                alloc_profile = info->avail_data_alloc_bits &
+                        info->data_alloc_profile;
+                data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
+        } else if (root == root->fs_info->chunk_root) {
+                alloc_profile = info->avail_system_alloc_bits &
+                        info->system_alloc_profile;
+                data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
+        } else {
+                alloc_profile = info->avail_metadata_alloc_bits &
+                        info->metadata_alloc_profile;
+                data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
+        }
+
+        return btrfs_reduce_alloc_profile(root, data);
+}
+
+void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
+{
+        u64 alloc_target;
+
+        alloc_target = btrfs_get_alloc_profile(root, 1);
+        BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
+                                                       alloc_target);
+}
+
+/*
+ * for now this just makes sure we have at least 5% of our metadata space free
+ * for use.
+ */
+int btrfs_check_metadata_free_space(struct btrfs_root *root)
+{
+        struct btrfs_fs_info *info = root->fs_info;
+        struct btrfs_space_info *meta_sinfo;
+        u64 alloc_target, thresh;
+
+        /* get the space info for where the metadata will live */
+        alloc_target = btrfs_get_alloc_profile(root, 0);
+        meta_sinfo = __find_space_info(info, alloc_target);
+
+        /*
+         * if the metadata area isn't maxed out then there is no sense in
+         * checking how much is used, since we can always allocate a new chunk
+         */
+        if (!meta_sinfo->full)
+                return 0;
+
+        spin_lock(&meta_sinfo->lock);
+        thresh = meta_sinfo->total_bytes * 95;
+
+        do_div(thresh, 100);
+
+        if (meta_sinfo->bytes_used + meta_sinfo->bytes_reserved +
+            meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly > thresh) {
+                spin_unlock(&meta_sinfo->lock);
+                return -ENOSPC;
+        }
+        spin_unlock(&meta_sinfo->lock);
+
+        return 0;
+}
+
+/*
+ * This will check the space that the inode allocates from to make sure we have
+ * enough space for bytes.
+ */
+int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode,
+                                u64 bytes)
+{
+        struct btrfs_space_info *data_sinfo;
+        int ret = 0;
+
+        /* make sure bytes are sectorsize aligned */
+        bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+
+        data_sinfo = BTRFS_I(inode)->space_info;
+again:
+        /* make sure we have enough space to handle the data first */
+        spin_lock(&data_sinfo->lock);
+        if (data_sinfo->total_bytes - data_sinfo->bytes_used -
+            data_sinfo->bytes_delalloc - data_sinfo->bytes_reserved -
+            data_sinfo->bytes_pinned - data_sinfo->bytes_readonly -
+            data_sinfo->bytes_may_use < bytes) {
+                /*
+                 * if we don't have enough free bytes in this space then we need
+                 * to alloc a new chunk.
+                 */
+                if (!data_sinfo->full) {
+                        u64 alloc_target;
+                        struct btrfs_trans_handle *trans;
+
+                        data_sinfo->force_alloc = 1;
+                        spin_unlock(&data_sinfo->lock);
+
+                        alloc_target = btrfs_get_alloc_profile(root, 1);
+                        trans = btrfs_start_transaction(root, 1);
+                        if (!trans)
+                                return -ENOMEM;
+
+                        ret = do_chunk_alloc(trans, root->fs_info->extent_root,
+                                             bytes + 2 * 1024 * 1024,
+                                             alloc_target, 0);
+                        btrfs_end_transaction(trans, root);
+                        if (ret)
+                                return ret;
+                        goto again;
+                }
+                spin_unlock(&data_sinfo->lock);
+                printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes"
+                       ", %llu bytes_used, %llu bytes_reserved, "
+                       "%llu bytes_pinned, %llu bytes_readonly, %llu may use"
+                       "%llu total\n", bytes, data_sinfo->bytes_delalloc,
+                       data_sinfo->bytes_used, data_sinfo->bytes_reserved,
+                       data_sinfo->bytes_pinned, data_sinfo->bytes_readonly,
+                       data_sinfo->bytes_may_use, data_sinfo->total_bytes);
+                return -ENOSPC;
+        }
+        data_sinfo->bytes_may_use += bytes;
+        BTRFS_I(inode)->reserved_bytes += bytes;
+        spin_unlock(&data_sinfo->lock);
+
+        return btrfs_check_metadata_free_space(root);
+}
+
+/*
+ * if there was an error for whatever reason after calling
+ * btrfs_check_data_free_space, call this so we can cleanup the counters.
+ */
+void btrfs_free_reserved_data_space(struct btrfs_root *root,
+                                    struct inode *inode, u64 bytes)
+{
+        struct btrfs_space_info *data_sinfo;
+
+        /* make sure bytes are sectorsize aligned */
+        bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
+
+        data_sinfo = BTRFS_I(inode)->space_info;
+        spin_lock(&data_sinfo->lock);
+        data_sinfo->bytes_may_use -= bytes;
+        BTRFS_I(inode)->reserved_bytes -= bytes;
+        spin_unlock(&data_sinfo->lock);
+}
+
+/* called when we are adding a delalloc extent to the inode's io_tree */
+void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode,
+                                  u64 bytes)
+{
+        struct btrfs_space_info *data_sinfo;
+
+        /* get the space info for where this inode will be storing its data */
+        data_sinfo = BTRFS_I(inode)->space_info;
+
+        /* make sure we have enough space to handle the data first */
+        spin_lock(&data_sinfo->lock);
+        data_sinfo->bytes_delalloc += bytes;
+
+        /*
+         * we are adding a delalloc extent without calling
+         * btrfs_check_data_free_space first.  This happens on a weird
+         * writepage condition, but shouldn't hurt our accounting
+         */
+        if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) {
+                data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes;
+                BTRFS_I(inode)->reserved_bytes = 0;
+        } else {
+                data_sinfo->bytes_may_use -= bytes;
+                BTRFS_I(inode)->reserved_bytes -= bytes;
+        }
+
+        spin_unlock(&data_sinfo->lock);
+}
+
+/* called when we are clearing an delalloc extent from the inode's io_tree */
+void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode,
+                              u64 bytes)
+{
+        struct btrfs_space_info *info;
+
+        info = BTRFS_I(inode)->space_info;
+
+        spin_lock(&info->lock);
+        info->bytes_delalloc -= bytes;
+        spin_unlock(&info->lock);
+}
+
 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
                           struct btrfs_root *extent_root, u64 alloc_bytes,
                           u64 flags, int force)
@@ -3105,6 +3300,10 @@ static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
                (unsigned long long)(info->total_bytes - info->bytes_used -
                                     info->bytes_pinned - info->bytes_reserved),
                (info->full) ? "" : "not ");
+        printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu,"
+               " may_use=%llu, used=%llu\n", info->total_bytes,
+               info->bytes_pinned, info->bytes_delalloc, info->bytes_may_use,
+               info->bytes_used);
 
         down_read(&info->groups_sem);
         list_for_each_entry(cache, &info->block_groups, list) {
@@ -3131,24 +3330,10 @@ static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
 {
         int ret;
         u64 search_start = 0;
-        u64 alloc_profile;
         struct btrfs_fs_info *info = root->fs_info;
 
-        if (data) {
-                alloc_profile = info->avail_data_alloc_bits &
-                        info->data_alloc_profile;
-                data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
-        } else if (root == root->fs_info->chunk_root) {
-                alloc_profile = info->avail_system_alloc_bits &
-                        info->system_alloc_profile;
-                data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
-        } else {
-                alloc_profile = info->avail_metadata_alloc_bits &
-                        info->metadata_alloc_profile;
-                data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
-        }
+        data = btrfs_get_alloc_profile(root, data);
 again:
-        data = btrfs_reduce_alloc_profile(root, data);
         /*
          * the only place that sets empty_size is btrfs_realloc_node, which
          * is not called recursively on allocations
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 872f104576e5..dc78954861b3 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1091,19 +1091,24 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                 WARN_ON(num_pages > nrptrs);
                 memset(pages, 0, sizeof(struct page *) * nrptrs);
 
-                ret = btrfs_check_free_space(root, write_bytes, 0);
+                ret = btrfs_check_data_free_space(root, inode, write_bytes);
                 if (ret)
                         goto out;
 
                 ret = prepare_pages(root, file, pages, num_pages,
                                     pos, first_index, last_index,
                                     write_bytes);
-                if (ret)
+                if (ret) {
+                        btrfs_free_reserved_data_space(root, inode,
+                                                       write_bytes);
                         goto out;
+                }
 
                 ret = btrfs_copy_from_user(pos, num_pages,
                                            write_bytes, pages, buf);
                 if (ret) {
+                        btrfs_free_reserved_data_space(root, inode,
+                                                       write_bytes);
                         btrfs_drop_pages(pages, num_pages);
                         goto out;
                 }
@@ -1111,8 +1116,11 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
                 ret = dirty_and_release_pages(NULL, root, file, pages,
                                               num_pages, pos, write_bytes);
                 btrfs_drop_pages(pages, num_pages);
-                if (ret)
+                if (ret) {
+                        btrfs_free_reserved_data_space(root, inode,
+                                                       write_bytes);
                         goto out;
+                }
 
                 if (will_write) {
                         btrfs_fdatawrite_range(inode->i_mapping, pos,
@@ -1136,6 +1144,8 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
         }
 out:
         mutex_unlock(&inode->i_mutex);
+        if (ret)
+                err = ret;
 
 out_nolock:
         kfree(pages);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3cee77ae03c8..7d4f948bc22a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -102,34 +102,6 @@ static int btrfs_init_inode_security(struct inode *inode,  struct inode *dir)
 }
 
 /*
- * a very lame attempt at stopping writes when the FS is 85% full.  There
- * are countless ways this is incorrect, but it is better than nothing.
- */
-int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
-                           int for_del)
-{
-        u64 total;
-        u64 used;
-        u64 thresh;
-        int ret = 0;
-
-        spin_lock(&root->fs_info->delalloc_lock);
-        total = btrfs_super_total_bytes(&root->fs_info->super_copy);
-        used = btrfs_super_bytes_used(&root->fs_info->super_copy);
-        if (for_del)
-                thresh = total * 90;
-        else
-                thresh = total * 85;
-
-        do_div(thresh, 100);
-
-        if (used + root->fs_info->delalloc_bytes + num_required > thresh)
-                ret = -ENOSPC;
-        spin_unlock(&root->fs_info->delalloc_lock);
-        return ret;
-}
-
-/*
  * this does all the hard work for inserting an inline extent into
  * the btree.  The caller should have done a btrfs_drop_extents so that
  * no overlapping inline items exist in the btree
@@ -1190,6 +1162,7 @@ static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
          */
         if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
                 struct btrfs_root *root = BTRFS_I(inode)->root;
+                btrfs_delalloc_reserve_space(root, inode, end - start + 1);
                 spin_lock(&root->fs_info->delalloc_lock);
                 BTRFS_I(inode)->delalloc_bytes += end - start + 1;
                 root->fs_info->delalloc_bytes += end - start + 1;
@@ -1223,9 +1196,12 @@ static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
                                (unsigned long long)end - start + 1,
                                (unsigned long long)
                                root->fs_info->delalloc_bytes);
+                        btrfs_delalloc_free_space(root, inode, (u64)-1);
                         root->fs_info->delalloc_bytes = 0;
                         BTRFS_I(inode)->delalloc_bytes = 0;
                 } else {
+                        btrfs_delalloc_free_space(root, inode,
+                                                  end - start + 1);
                         root->fs_info->delalloc_bytes -= end - start + 1;
                         BTRFS_I(inode)->delalloc_bytes -= end - start + 1;
                 }
@@ -2245,10 +2221,6 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 
         root = BTRFS_I(dir)->root;
 
-        ret = btrfs_check_free_space(root, 1, 1);
-        if (ret)
-                goto fail;
-
         trans = btrfs_start_transaction(root, 1);
 
         btrfs_set_trans_block_group(trans, dir);
@@ -2261,7 +2233,6 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
         nr = trans->blocks_used;
 
         btrfs_end_transaction_throttle(trans, root);
-fail:
         btrfs_btree_balance_dirty(root, nr);
         return ret;
 }
@@ -2284,10 +2255,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
                 return -ENOTEMPTY;
         }
 
-        ret = btrfs_check_free_space(root, 1, 1);
-        if (ret)
-                goto fail;
-
         trans = btrfs_start_transaction(root, 1);
         btrfs_set_trans_block_group(trans, dir);
 
@@ -2304,7 +2271,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 fail_trans:
         nr = trans->blocks_used;
         ret = btrfs_end_transaction_throttle(trans, root);
-fail:
         btrfs_btree_balance_dirty(root, nr);
 
         if (ret && !err)
@@ -2818,7 +2784,7 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
         if (size <= hole_start)
                 return 0;
 
-        err = btrfs_check_free_space(root, 1, 0);
+        err = btrfs_check_metadata_free_space(root);
         if (err)
                 return err;
 
@@ -3014,6 +2980,7 @@ static noinline void init_btrfs_i(struct inode *inode)
         bi->last_trans = 0;
         bi->logged_trans = 0;
         bi->delalloc_bytes = 0;
+        bi->reserved_bytes = 0;
         bi->disk_i_size = 0;
         bi->flags = 0;
         bi->index_cnt = (u64)-1;
@@ -3035,6 +3002,7 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p)
         inode->i_ino = args->ino;
         init_btrfs_i(inode);
         BTRFS_I(inode)->root = args->root;
+        btrfs_set_inode_space_info(args->root, inode);
         return 0;
 }
 
@@ -3455,6 +3423,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
         BTRFS_I(inode)->index_cnt = 2;
         BTRFS_I(inode)->root = root;
         BTRFS_I(inode)->generation = trans->transid;
+        btrfs_set_inode_space_info(root, inode);
 
         if (mode & S_IFDIR)
                 owner = 0;
@@ -3602,7 +3571,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
         if (!new_valid_dev(rdev))
                 return -EINVAL;
 
-        err = btrfs_check_free_space(root, 1, 0);
+        err = btrfs_check_metadata_free_space(root);
         if (err)
                 goto fail;
 
@@ -3665,7 +3634,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
         u64 objectid;
         u64 index = 0;
 
-        err = btrfs_check_free_space(root, 1, 0);
+        err = btrfs_check_metadata_free_space(root);
         if (err)
                 goto fail;
         trans = btrfs_start_transaction(root, 1);
@@ -3733,7 +3702,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
                 return -ENOENT;
 
         btrfs_inc_nlink(inode);
-        err = btrfs_check_free_space(root, 1, 0);
+        err = btrfs_check_metadata_free_space(root);
         if (err)
                 goto fail;
         err = btrfs_set_inode_index(dir, &index);
@@ -3779,7 +3748,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         u64 index = 0;
         unsigned long nr = 1;
 
-        err = btrfs_check_free_space(root, 1, 0);
+        err = btrfs_check_metadata_free_space(root);
         if (err)
                 goto out_unlock;
 
@@ -4336,7 +4305,7 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
         u64 page_start;
         u64 page_end;
 
-        ret = btrfs_check_free_space(root, PAGE_CACHE_SIZE, 0);
+        ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
         if (ret)
                 goto out;
 
@@ -4349,6 +4318,7 @@ again:
 
         if ((page->mapping != inode->i_mapping) ||
             (page_start >= size)) {
+                btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
                 /* page got truncated out from underneath us */
                 goto out_unlock;
         }
@@ -4631,7 +4601,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
                 return -EXDEV;
 
-        ret = btrfs_check_free_space(root, 1, 0);
+        ret = btrfs_check_metadata_free_space(root);
         if (ret)
                 goto out_unlock;
 
@@ -4749,7 +4719,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
                 return -ENAMETOOLONG;
 
-        err = btrfs_check_free_space(root, 1, 0);
+        err = btrfs_check_metadata_free_space(root);
         if (err)
                 goto out_fail;
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 988fdc8b49eb..bca729fc80c8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -70,7 +70,7 @@ static noinline int create_subvol(struct btrfs_root *root,
         u64 index = 0;
         unsigned long nr = 1;
 
-        ret = btrfs_check_free_space(root, 1, 0);
+        ret = btrfs_check_metadata_free_space(root);
         if (ret)
                 goto fail_commit;
 
@@ -203,7 +203,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
         if (!root->ref_cows)
                 return -EINVAL;
 
-        ret = btrfs_check_free_space(root, 1, 0);
+        ret = btrfs_check_metadata_free_space(root);
         if (ret)
                 goto fail_unlock;
 
@@ -374,7 +374,7 @@ static int btrfs_defrag_file(struct file *file)
         unsigned long i;
         int ret;
 
-        ret = btrfs_check_free_space(root, inode->i_size, 0);
+        ret = btrfs_check_data_free_space(root, inode, inode->i_size);
         if (ret)
                 return -ENOSPC;