9 files changed, 257 insertions, 50 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 6369bacf0dcb..495ab21b9832 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -1701,7 +1701,12 @@ ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
         }
 
         sbi = EXT4_SB(sb);
-        *count = ext4_has_free_blocks(sbi, *count);
+        if (!EXT4_I(inode)->i_delalloc_reserved_flag) {
+                /*
+                 * With delalloc we already reserved the blocks
+                 */
+                *count = ext4_has_free_blocks(sbi, *count);
+        }
         if (*count == 0) {
                 *errp = -ENOSPC;
                 return 0;       /*return with ENOSPC error */
@@ -1902,7 +1907,8 @@ allocated:
         le16_add_cpu(&gdp->bg_free_blocks_count, -num);
         gdp->bg_checksum = ext4_group_desc_csum(sbi, group_no, gdp);
         spin_unlock(sb_bgl_lock(sbi, group_no));
-        percpu_counter_sub(&sbi->s_freeblocks_counter, num);
+        if (!EXT4_I(inode)->i_delalloc_reserved_flag)
+                percpu_counter_sub(&sbi->s_freeblocks_counter, num);
 
         if (sbi->s_log_groups_per_flex) {
                 ext4_group_t flex_group = ext4_flex_group(sbi, group_no);
@@ -1976,40 +1982,49 @@ static ext4_fsblk_t do_blk_alloc(handle_t *handle, struct inode *inode,
 }
 
 /*
- * ext4_new_meta_block() -- allocate block for meta data (indexing) blocks
+ * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
  *
  * @handle:             handle to this transaction
  * @inode:              file inode
  * @goal:               given target block(filesystem wide)
+ * @count:              total number of blocks need
  * @errp:               error code
  *
- * Return allocated block number on success
+ * Return 1st allocated block numberon success, *count stores total account
+ * error stores in errp pointer
  */
-ext4_fsblk_t ext4_new_meta_block(handle_t *handle, struct inode *inode,
-                ext4_fsblk_t goal, int *errp)
+ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
+                ext4_fsblk_t goal, unsigned long *count, int *errp)
 {
-        unsigned long count = 1;
-        return do_blk_alloc(handle, inode, 0, goal,
-                        &count, errp, EXT4_META_BLOCK);
+        ext4_fsblk_t ret;
+        ret = do_blk_alloc(handle, inode, 0, goal,
+                                count, errp, EXT4_META_BLOCK);
+        /*
+         * Account for the allocated meta blocks
+         */
+        if (!(*errp)) {
+                spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+                EXT4_I(inode)->i_allocated_meta_blocks += *count;
+                spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+        }
+        return ret;
 }
 
 /*
- * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
+ * ext4_new_meta_block() -- allocate block for meta data (indexing) blocks
  *
  * @handle:             handle to this transaction
  * @inode:              file inode
  * @goal:               given target block(filesystem wide)
- * @count:              total number of blocks need
  * @errp:               error code
  *
- * Return 1st allocated block numberon success, *count stores total account
- * error stores in errp pointer
+ * Return allocated block number on success
  */
-ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
-                ext4_fsblk_t goal, unsigned long *count, int *errp)
+ext4_fsblk_t ext4_new_meta_block(handle_t *handle, struct inode *inode,
+                ext4_fsblk_t goal, int *errp)
 {
-        return do_blk_alloc(handle, inode, 0, goal,
-                        count, errp, EXT4_META_BLOCK);
+        unsigned long count = 1;
+        return ext4_new_meta_blocks(handle, inode, goal, &count, errp);
 }
 
 /*
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 5ed5108766c1..d3d23d73c08b 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -129,7 +129,8 @@ static int ext4_readdir(struct file * filp,
                 struct buffer_head *bh = NULL;
 
                 map_bh.b_state = 0;
-                err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh, 0, 0);
+                err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh,
+                                                0, 0, 0);
                 if (err > 0) {
                         pgoff_t index = map_bh.b_blocknr >>
                                         (PAGE_CACHE_SHIFT - inode->i_blkbits);
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ee9576dc0ba1..0962f4e26579 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -74,6 +74,9 @@
 #define EXT4_MB_HINT_GOAL_ONLY          256
 /* goal is meaningful */
 #define EXT4_MB_HINT_TRY_GOAL           512
+/* blocks already pre-reserved by delayed allocation */
+#define EXT4_MB_DELALLOC_RESERVED      1024
+
 
 struct ext4_allocation_request {
         /* target inode for block we're allocating */
@@ -1041,6 +1044,7 @@ extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
 
 
 /* inode.c */
+void ext4_da_release_space(struct inode *inode, int used, int to_free);
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
                 struct buffer_head *bh, ext4_fsblk_t blocknr);
 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
@@ -1234,7 +1238,7 @@ extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
 extern int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode,
                         sector_t block, unsigned long max_blocks,
                         struct buffer_head *bh, int create,
-                        int extend_disksize);
+                        int extend_disksize, int flag);
 #endif  /* __KERNEL__ */
 
 #endif  /* _EXT4_H */
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 75333b595fab..6c166c0a54b7 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -212,6 +212,7 @@ static inline int ext4_ext_get_actual_len(struct ext4_extent *ext)
                 (le16_to_cpu(ext->ee_len) - EXT_INIT_MAX_LEN));
 }
 
+extern int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks);
 extern ext4_fsblk_t idx_pblock(struct ext4_extent_idx *);
 extern void ext4_ext_store_pblock(struct ext4_extent *, ext4_fsblk_t);
 extern int ext4_extent_tree_init(handle_t *, struct inode *);
diff --git a/fs/ext4/ext4_i.h b/fs/ext4/ext4_i.h
index c2903ef72159..ef7409f0e7e4 100644
--- a/fs/ext4/ext4_i.h
+++ b/fs/ext4/ext4_i.h
@@ -163,6 +163,13 @@ struct ext4_inode_info {
         /* mballoc */
         struct list_head i_prealloc_list;
         spinlock_t i_prealloc_lock;
+
+        /* allocation reservation info for delalloc */
+        unsigned long i_reserved_data_blocks;
+        unsigned long i_reserved_meta_blocks;
+        unsigned long i_allocated_meta_blocks;
+        unsigned short i_delalloc_reserved_flag;
+        spinlock_t i_block_reservation_lock;
 };
 
 #endif  /* _EXT4_I */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 7844bbb2bac0..dabc3b68d249 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -248,6 +248,36 @@ static int ext4_ext_space_root_idx(struct inode *inode)
         return size;
 }
 
+/*
+ * Calculate the number of metadata blocks needed
+ * to allocate @blocks
+ * Worse case is one block per extent
+ */
+int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
+{
+        int lcap, icap, rcap, leafs, idxs, num;
+        int newextents = blocks;
+
+        rcap = ext4_ext_space_root_idx(inode);
+        lcap = ext4_ext_space_block(inode);
+        icap = ext4_ext_space_block_idx(inode);
+
+        /* number of new leaf blocks needed */
+        num = leafs = (newextents + lcap - 1) / lcap;
+
+        /*
+         * Worse case, we need separate index block(s)
+         * to link all new leaf blocks
+         */
+        idxs = (leafs + icap - 1) / icap;
+        do {
+                num += idxs;
+                idxs = (idxs + icap - 1) / icap;
+        } while (idxs > rcap);
+
+        return num;
+}
+
 static int
 ext4_ext_max_entries(struct inode *inode, int depth)
 {
@@ -2910,7 +2940,7 @@ retry:
                 }
                 ret = ext4_get_blocks_wrap(handle, inode, block,
                                           max_blocks, &map_bh,
-                                          EXT4_CREATE_UNINITIALIZED_EXT, 0);
+                                          EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);
                 if (ret <= 0) {
 #ifdef EXT4FS_DEBUG
                         WARN_ON(ret <= 0);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2bef4f879e4b..a6b800c58474 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -39,6 +39,7 @@
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "ext4_extents.h"
 
 static inline int ext4_begin_ordered_truncate(struct inode *inode,
                                               loff_t new_size)
@@ -982,7 +983,7 @@ out:
  */
 int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                         unsigned long max_blocks, struct buffer_head *bh,
-                        int create, int extend_disksize)
+                        int create, int extend_disksize, int flag)
 {
         int retval;
 
@@ -1023,6 +1024,15 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
          * with create == 1 flag.
          */
         down_write((&EXT4_I(inode)->i_data_sem));
+
+        /*
+         * if the caller is from delayed allocation writeout path
+         * we have already reserved fs blocks for allocation
+         * let the underlying get_block() function know to
+         * avoid double accounting
+         */
+        if (flag)
+                EXT4_I(inode)->i_delalloc_reserved_flag = 1;
         /*
          * We need to check for EXT4 here because migrate
          * could have changed the inode type in between
@@ -1044,6 +1054,18 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                                                         ~EXT4_EXT_MIGRATE;
                 }
         }
+
+        if (flag) {
+                EXT4_I(inode)->i_delalloc_reserved_flag = 0;
+                /*
+                 * Update reserved blocks/metadata blocks
+                 * after successful block allocation
+                 * which were deferred till now
+                 */
+                if ((retval > 0) && buffer_delay(bh))
+                        ext4_da_release_space(inode, retval, 0);
+        }
+
         up_write((&EXT4_I(inode)->i_data_sem));
         return retval;
 }
@@ -1069,7 +1091,7 @@ static int ext4_get_block(struct inode *inode, sector_t iblock,
         }
 
         ret = ext4_get_blocks_wrap(handle, inode, iblock,
-                                        max_blocks, bh_result, create, 0);
+                                        max_blocks, bh_result, create, 0, 0);
         if (ret > 0) {
                 bh_result->b_size = (ret << inode->i_blkbits);
                 ret = 0;
@@ -1095,7 +1117,7 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
         dummy.b_blocknr = -1000;
         buffer_trace_init(&dummy.b_history);
         err = ext4_get_blocks_wrap(handle, inode, block, 1,
-                                        &dummy, create, 1);
+                                        &dummy, create, 1, 0);
         /*
          * ext4_get_blocks_handle() returns number of blocks
          * mapped. 0 in case of a HOLE.
@@ -1409,6 +1431,122 @@ static int ext4_journalled_write_end(struct file *file,
 
         return ret ? ret : copied;
 }
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate @blocks for non extent file based file
+ */
+static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+{
+        int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+        int ind_blks, dind_blks, tind_blks;
+
+        /* number of new indirect blocks needed */
+        ind_blks = (blocks + icap - 1) / icap;
+
+        dind_blks = (ind_blks + icap - 1) / icap;
+
+        tind_blks = 1;
+
+        return ind_blks + dind_blks + tind_blks;
+}
+
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate given number of blocks
+ */
+static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+{
+        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
+                return ext4_ext_calc_metadata_amount(inode, blocks);
+
+        return ext4_indirect_calc_metadata_amount(inode, blocks);
+}
+
+static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+       unsigned long md_needed, mdblocks, total = 0;
+
+        /*
+         * recalculate the amount of metadata blocks to reserve
+         * in order to allocate nrblocks
+         * worse case is one extent per block
+         */
+        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+        total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
+        mdblocks = ext4_calc_metadata_amount(inode, total);
+        BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks);
+
+        md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
+        total = md_needed + nrblocks;
+
+        if (ext4_has_free_blocks(sbi, total) < total) {
+                spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+                return -ENOSPC;
+        }
+
+        /* reduce fs free blocks counter */
+        percpu_counter_sub(&sbi->s_freeblocks_counter, total);
+
+        EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
+        EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
+
+        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+        return 0;       /* success */
+}
+
+void ext4_da_release_space(struct inode *inode, int used, int to_free)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+        int total, mdb, mdb_free, release;
+
+        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+        /* recalculate the number of metablocks still need to be reserved */
+        total = EXT4_I(inode)->i_reserved_data_blocks - used - to_free;
+        mdb = ext4_calc_metadata_amount(inode, total);
+
+        /* figure out how many metablocks to release */
+        BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+        mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
+
+        /* Account for allocated meta_blocks */
+        mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+
+        release = to_free + mdb_free;
+
+        /* update fs free blocks counter for truncate case */
+        percpu_counter_add(&sbi->s_freeblocks_counter, release);
+
+        /* update per-inode reservations */
+        BUG_ON(used + to_free > EXT4_I(inode)->i_reserved_data_blocks);
+        EXT4_I(inode)->i_reserved_data_blocks -= (used + to_free);
+
+        BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+        EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+        EXT4_I(inode)->i_allocated_meta_blocks = 0;
+        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+}
+
+static void ext4_da_page_release_reservation(struct page *page,
+                                                unsigned long offset)
+{
+        int to_release = 0;
+        struct buffer_head *head, *bh;
+        unsigned int curr_off = 0;
+
+        head = page_buffers(page);
+        bh = head;
+        do {
+                unsigned int next_off = curr_off + bh->b_size;
+
+                if ((offset <= curr_off) && (buffer_delay(bh))) {
+                        to_release++;
+                        clear_buffer_delay(bh);
+                }
+                curr_off = next_off;
+        } while ((bh = bh->b_this_page) != head);
+        ext4_da_release_space(page->mapping->host, 0, to_release);
+}
 
 /*
  * Delayed allocation stuff
@@ -1829,14 +1967,18 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
          * preallocated blocks are unmapped but should treated
          * the same as allocated blocks.
          */
-        ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1,  bh_result, 0, 0);
-        if (ret == 0) {
-                /* the block isn't allocated yet, let's reserve space */
-                /* XXX: call reservation here */
+        ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1,  bh_result, 0, 0, 0);
+        if ((ret == 0) && !buffer_delay(bh_result)) {
+                /* the block isn't (pre)allocated yet, let's reserve space */
                 /*
                  * XXX: __block_prepare_write() unmaps passed block,
                  * is it OK?
                  */
+                ret = ext4_da_reserve_space(inode, 1);
+                if (ret)
+                        /* not enough space to reserve */
+                        return ret;
+
                 map_bh(bh_result, inode->i_sb, 0);
                 set_buffer_new(bh_result);
                 set_buffer_delay(bh_result);
@@ -1847,7 +1989,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 
         return ret;
 }
-
+#define         EXT4_DELALLOC_RSVED     1
 static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
                                    struct buffer_head *bh_result, int create)
 {
@@ -1865,7 +2007,7 @@ static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
         }
 
         ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
-                                   bh_result, create, 0);
+                                   bh_result, create, 0, EXT4_DELALLOC_RSVED);
         if (ret > 0) {
                 bh_result->b_size = (ret << inode->i_blkbits);
 
@@ -1952,7 +2094,7 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
                                 loff_t pos, unsigned len, unsigned flags,
                                 struct page **pagep, void **fsdata)
 {
-        int ret;
+        int ret, retries = 0;
         struct page *page;
         pgoff_t index;
         unsigned from, to;
@@ -1963,6 +2105,7 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
         from = pos & (PAGE_CACHE_SIZE - 1);
         to = from + len;
 
+retry:
         /*
          * With delayed allocation, we don't log the i_disksize update
          * if there is delayed block allocation. But we still need
@@ -1988,6 +2131,8 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
                 page_cache_release(page);
         }
 
+        if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+                goto retry;
 out:
         return ret;
 }
@@ -2040,9 +2185,6 @@ static int ext4_da_write_end(struct file *file,
 
 static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
 {
-        struct buffer_head *head, *bh;
-        unsigned int curr_off = 0;
-
         /*
          * Drop reserved blocks
          */
@@ -2050,21 +2192,7 @@ static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
         if (!page_has_buffers(page))
                 goto out;
 
-        head = page_buffers(page);
-        bh = head;
-        do {
-                unsigned int next_off = curr_off + bh->b_size;
-
-                /*
-                 * is this block fully invalidated?
-                 */
-                if (offset <= curr_off && buffer_delay(bh)) {
-                        clear_buffer_delay(bh);
-                        /* XXX: add real stuff here */
-                }
-                curr_off = next_off;
-                bh = bh->b_this_page;
-        } while (bh != head);
+        ext4_da_page_release_reservation(page, offset);
 
 out:
         ext4_invalidatepage(page, offset);
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 8d254ca83d9e..8d141a25bbee 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2964,7 +2964,15 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
         le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len);
         gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
         spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
-        percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
+
+        /*
+         * free blocks account has already be reduced/reserved
+         * at write_begin() time for delayed allocation
+         * do not double accounting
+         */
+        if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
+                percpu_counter_sub(&sbi->s_freeblocks_counter,
+                                        ac->ac_b_ex.fe_len);
 
         if (sbi->s_log_groups_per_flex) {
                 ext4_group_t flex_group = ext4_flex_group(sbi,
@@ -4169,7 +4177,12 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
                                             &(ar->len), errp);
                 return block;
         }
-        ar->len = ext4_has_free_blocks(sbi, ar->len);
+        if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag) {
+                /*
+                 * With delalloc we already reserved the blocks
+                 */
+                ar->len = ext4_has_free_blocks(sbi, ar->len);
+        }
 
         if (ar->len == 0) {
                 *errp = -ENOSPC;
@@ -4186,6 +4199,9 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
         }
         inquota = ar->len;
 
+        if (EXT4_I(ar->inode)->i_delalloc_reserved_flag)
+                ar->flags |= EXT4_MB_DELALLOC_RESERVED;
+
         ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
         if (!ac) {
                 ar->len = 0;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index de9d3d0eb203..25e2f2488cd2 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -574,6 +574,11 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
         INIT_LIST_HEAD(&ei->i_prealloc_list);
         spin_lock_init(&ei->i_prealloc_lock);
         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
+        ei->i_reserved_data_blocks = 0;
+        ei->i_reserved_meta_blocks = 0;
+        ei->i_allocated_meta_blocks = 0;
+        ei->i_delalloc_reserved_flag = 0;
+        spin_lock_init(&(ei->i_block_reservation_lock));
         return &ei->vfs_inode;
 }