1 files changed, 91 insertions, 59 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 84eeb8f..e119524 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1009,49 +1009,56 @@ qsize_t *ext4_get_reserved_space(struct inode *inode)
 	return &EXT4_I(inode)->i_reserved_quota;
 }
 #endif
+
 /*
  * Calculate the number of metadata blocks need to reserve
- * to allocate @blocks for non extent file based file
+ * to allocate a new block at @lblocks for non extent file based file
  */
-static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+static int ext4_indirect_calc_metadata_amount(struct inode *inode,
+					      sector_t lblock)
 {
-	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;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	int dind_mask = EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1;
+	int blk_bits;
 
-	dind_blks = (ind_blks + icap - 1) / icap;
+	if (lblock < EXT4_NDIR_BLOCKS)
+		return 0;
 
-	tind_blks = 1;
+	lblock -= EXT4_NDIR_BLOCKS;
 
-	return ind_blks + dind_blks + tind_blks;
+	if (ei->i_da_metadata_calc_len &&
+	    (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
+		ei->i_da_metadata_calc_len++;
+		return 0;
+	}
+	ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
+	ei->i_da_metadata_calc_len = 1;
+	blk_bits = roundup_pow_of_two(lblock + 1);
+	return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
 }
 
 /*
  * Calculate the number of metadata blocks need to reserve
- * to allocate given number of blocks
+ * to allocate a block located at @lblock
  */
-static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+static int ext4_calc_metadata_amount(struct inode *inode, sector_t lblock)
 {
-	if (!blocks)
-		return 0;
-
 	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-		return ext4_ext_calc_metadata_amount(inode, blocks);
+		return ext4_ext_calc_metadata_amount(inode, lblock);
 
-	return ext4_indirect_calc_metadata_amount(inode, blocks);
+	return ext4_indirect_calc_metadata_amount(inode, lblock);
 }
 
 /*
  * Called with i_data_sem down, which is important since we can call
  * ext4_discard_preallocations() from here.
  */
-static void ext4_da_update_reserve_space(struct inode *inode, int used)
+void ext4_da_update_reserve_space(struct inode *inode,
+					int used, int quota_claim)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	int mdb_free = 0;
+	int mdb_free = 0, allocated_meta_blocks = 0;
 
 	spin_lock(&ei->i_block_reservation_lock);
 	if (unlikely(used > ei->i_reserved_data_blocks)) {
@@ -1067,6 +1074,7 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
 	ei->i_reserved_data_blocks -= used;
 	used += ei->i_allocated_meta_blocks;
 	ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
+	allocated_meta_blocks = ei->i_allocated_meta_blocks;
 	ei->i_allocated_meta_blocks = 0;
 	percpu_counter_sub(&sbi->s_dirtyblocks_counter, used);
 
@@ -1076,16 +1084,31 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
 		 * only when we have written all of the delayed
 		 * allocation blocks.
 		 */
-		mdb_free = ei->i_allocated_meta_blocks;
+		mdb_free = ei->i_reserved_meta_blocks;
+		ei->i_reserved_meta_blocks = 0;
+		ei->i_da_metadata_calc_len = 0;
 		percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
-		ei->i_allocated_meta_blocks = 0;
 	}
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 
 	/* Update quota subsystem */
-	vfs_dq_claim_block(inode, used);
-	if (mdb_free)
-		vfs_dq_release_reservation_block(inode, mdb_free);
+	if (quota_claim) {
+		vfs_dq_claim_block(inode, used);
+		if (mdb_free)
+			vfs_dq_release_reservation_block(inode, mdb_free);
+	} else {
+		/*
+		 * We did fallocate with an offset that is already delayed
+		 * allocated. So on delayed allocated writeback we should
+		 * not update the quota for allocated blocks. But then
+		 * converting an fallocate region to initialized region would
+		 * have caused a metadata allocation. So claim quota for
+		 * that
+		 */
+		if (allocated_meta_blocks)
+			vfs_dq_claim_block(inode, allocated_meta_blocks);
+		vfs_dq_release_reservation_block(inode, mdb_free + used);
+	}
 
 	/*
 	 * If we have done all the pending block allocations and if
@@ -1285,18 +1308,20 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
 			 */
 			EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
 		}
-	}
 
+		/*
+		 * Update reserved blocks/metadata blocks after successful
+		 * block allocation which had been deferred till now. We don't
+		 * support fallocate for non extent files. So we can update
+		 * reserve space here.
+		 */
+		if ((retval > 0) &&
+			(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
+			ext4_da_update_reserve_space(inode, retval, 1);
+	}
 	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
 		EXT4_I(inode)->i_delalloc_reserved_flag = 0;
 
-	/*
-	 * Update reserved blocks/metadata blocks after successful
-	 * block allocation which had been deferred till now.
-	 */
-	if ((retval > 0) && (flags & EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE))
-		ext4_da_update_reserve_space(inode, retval);
-
 	up_write((&EXT4_I(inode)->i_data_sem));
 	if (retval > 0 && buffer_mapped(bh)) {
 		int ret = check_block_validity(inode, "file system "
@@ -1802,12 +1827,15 @@ static int ext4_journalled_write_end(struct file *file,
 	return ret ? ret : copied;
 }
 
-static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
+/*
+ * Reserve a single block located at lblock
+ */
+static int ext4_da_reserve_space(struct inode *inode, sector_t lblock)
 {
 	int retries = 0;
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	unsigned long md_needed, md_reserved, total = 0;
+	unsigned long md_needed, md_reserved;
 
 	/*
 	 * recalculate the amount of metadata blocks to reserve
@@ -1817,8 +1845,7 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
 repeat:
 	spin_lock(&ei->i_block_reservation_lock);
 	md_reserved = ei->i_reserved_meta_blocks;
-	md_needed = ext4_calc_metadata_amount(inode, nrblocks);
-	total = md_needed + nrblocks;
+	md_needed = ext4_calc_metadata_amount(inode, lblock);
 	spin_unlock(&ei->i_block_reservation_lock);
 
 	/*
@@ -1826,31 +1853,19 @@ repeat:
 	 * later. Real quota accounting is done at pages writeout
 	 * time.
 	 */
-	if (vfs_dq_reserve_block(inode, total)) {
-		/* 
-		 * We tend to badly over-estimate the amount of
-		 * metadata blocks which are needed, so if we have
-		 * reserved any metadata blocks, try to force out the
-		 * inode and see if we have any better luck.
-		 */
-		if (md_reserved && retries++ <= 3)
-			goto retry;
+	if (vfs_dq_reserve_block(inode, md_needed + 1))
 		return -EDQUOT;
-	}
 
-	if (ext4_claim_free_blocks(sbi, total)) {
-		vfs_dq_release_reservation_block(inode, total);
+	if (ext4_claim_free_blocks(sbi, md_needed + 1)) {
+		vfs_dq_release_reservation_block(inode, md_needed + 1);
 		if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
-		retry:
-			if (md_reserved)
-				write_inode_now(inode, (retries == 3));
 			yield();
 			goto repeat;
 		}
 		return -ENOSPC;
 	}
 	spin_lock(&ei->i_block_reservation_lock);
-	ei->i_reserved_data_blocks += nrblocks;
+	ei->i_reserved_data_blocks++;
 	ei->i_reserved_meta_blocks += md_needed;
 	spin_unlock(&ei->i_block_reservation_lock);
 
@@ -1889,8 +1904,9 @@ static void ext4_da_release_space(struct inode *inode, int to_free)
 		 * only when we have written all of the delayed
 		 * allocation blocks.
 		 */
-		to_free += ei->i_allocated_meta_blocks;
-		ei->i_allocated_meta_blocks = 0;
+		to_free += ei->i_reserved_meta_blocks;
+		ei->i_reserved_meta_blocks = 0;
+		ei->i_da_metadata_calc_len = 0;
 	}
 
 	/* update fs dirty blocks counter */
@@ -2203,10 +2219,10 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd)
 	 * variables are updated after the blocks have been allocated.
 	 */
 	new.b_state = 0;
-	get_blocks_flags = (EXT4_GET_BLOCKS_CREATE |
-			    EXT4_GET_BLOCKS_DELALLOC_RESERVE);
+	get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
 	if (mpd->b_state & (1 << BH_Delay))
-		get_blocks_flags |= EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE;
+		get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
+
 	blks = ext4_get_blocks(handle, mpd->inode, next, max_blocks,
 			       &new, get_blocks_flags);
 	if (blks < 0) {
@@ -2504,7 +2520,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 		 * XXX: __block_prepare_write() unmaps passed block,
 		 * is it OK?
 		 */
-		ret = ext4_da_reserve_space(inode, 1);
+		ret = ext4_da_reserve_space(inode, iblock);
 		if (ret)
 			/* not enough space to reserve */
 			return ret;
@@ -3022,7 +3038,7 @@ 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, retries = 0;
+	int ret, retries = 0, quota_retries = 0;
 	struct page *page;
 	pgoff_t index;
 	unsigned from, to;
@@ -3081,6 +3097,22 @@ retry:
 
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;
+
+	if ((ret == -EDQUOT) &&
+	    EXT4_I(inode)->i_reserved_meta_blocks &&
+	    (quota_retries++ < 3)) {
+		/*
+		 * Since we often over-estimate the number of meta
+		 * data blocks required, we may sometimes get a
+		 * spurios out of quota error even though there would
+		 * be enough space once we write the data blocks and
+		 * find out how many meta data blocks were _really_
+		 * required.  So try forcing the inode write to see if
+		 * that helps.
+		 */
+		write_inode_now(inode, (quota_retries == 3));
+		goto retry;
+	}
 out:
 	return ret;
 }