1 files changed, 128 insertions, 66 deletions

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 377ad172d74..9f9992b3792 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -13,6 +13,7 @@
 
 #include "ext2.h"
 #include <linux/quotaops.h>
+#include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/buffer_head.h>
 #include <linux/capability.h>
@@ -69,9 +70,53 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
 	return desc + offset;
 }
 
+static int ext2_valid_block_bitmap(struct super_block *sb,
+					struct ext2_group_desc *desc,
+					unsigned int block_group,
+					struct buffer_head *bh)
+{
+	ext2_grpblk_t offset;
+	ext2_grpblk_t next_zero_bit;
+	ext2_fsblk_t bitmap_blk;
+	ext2_fsblk_t group_first_block;
+
+	group_first_block = ext2_group_first_block_no(sb, block_group);
+
+	/* check whether block bitmap block number is set */
+	bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+	offset = bitmap_blk - group_first_block;
+	if (!ext2_test_bit(offset, bh->b_data))
+		/* bad block bitmap */
+		goto err_out;
+
+	/* check whether the inode bitmap block number is set */
+	bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+	offset = bitmap_blk - group_first_block;
+	if (!ext2_test_bit(offset, bh->b_data))
+		/* bad block bitmap */
+		goto err_out;
+
+	/* check whether the inode table block number is set */
+	bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+	offset = bitmap_blk - group_first_block;
+	next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
+				offset + EXT2_SB(sb)->s_itb_per_group,
+				offset);
+	if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group)
+		/* good bitmap for inode tables */
+		return 1;
+
+err_out:
+	ext2_error(sb, __func__,
+			"Invalid block bitmap - "
+			"block_group = %d, block = %lu",
+			block_group, bitmap_blk);
+	return 0;
+}
+
 /*
- * Read the bitmap for a given block_group, reading into the specified 
- * slot in the superblock's bitmap cache.
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
  *
  * Return buffer_head on success or NULL in case of failure.
  */
@@ -80,28 +125,38 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
 {
 	struct ext2_group_desc * desc;
 	struct buffer_head * bh = NULL;
-	
-	desc = ext2_get_group_desc (sb, block_group, NULL);
+	ext2_fsblk_t bitmap_blk;
+
+	desc = ext2_get_group_desc(sb, block_group, NULL);
 	if (!desc)
-		goto error_out;
-	bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
-	if (!bh)
-		ext2_error (sb, "read_block_bitmap",
+		return NULL;
+	bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+	bh = sb_getblk(sb, bitmap_blk);
+	if (unlikely(!bh)) {
+		ext2_error(sb, __func__,
 			    "Cannot read block bitmap - "
 			    "block_group = %d, block_bitmap = %u",
 			    block_group, le32_to_cpu(desc->bg_block_bitmap));
-error_out:
-	return bh;
-}
-
-static void release_blocks(struct super_block *sb, int count)
-{
-	if (count) {
-		struct ext2_sb_info *sbi = EXT2_SB(sb);
+		return NULL;
+	}
+	if (likely(bh_uptodate_or_lock(bh)))
+		return bh;
 
-		percpu_counter_add(&sbi->s_freeblocks_counter, count);
-		sb->s_dirt = 1;
+	if (bh_submit_read(bh) < 0) {
+		brelse(bh);
+		ext2_error(sb, __func__,
+			    "Cannot read block bitmap - "
+			    "block_group = %d, block_bitmap = %u",
+			    block_group, le32_to_cpu(desc->bg_block_bitmap));
+		return NULL;
 	}
+
+	ext2_valid_block_bitmap(sb, desc, block_group, bh);
+	/*
+	 * file system mounted not to panic on error, continue with corrupt
+	 * bitmap
+	 */
+	return bh;
 }
 
 static void group_adjust_blocks(struct super_block *sb, int group_no,
@@ -115,7 +170,6 @@ static void group_adjust_blocks(struct super_block *sb, int group_no,
 		free_blocks = le16_to_cpu(desc->bg_free_blocks_count);
 		desc->bg_free_blocks_count = cpu_to_le16(free_blocks + count);
 		spin_unlock(sb_bgl_lock(sbi, group_no));
-		sb->s_dirt = 1;
 		mark_buffer_dirty(bh);
 	}
 }
@@ -182,11 +236,10 @@ restart:
 		prev = rsv;
 	}
 	printk("Window map complete.\n");
-	if (bad)
-		BUG();
+	BUG_ON(bad);
 }
 #define rsv_window_dump(root, verbose) \
-	__rsv_window_dump((root), (verbose), __FUNCTION__)
+	__rsv_window_dump((root), (verbose), __func__)
 #else
 #define rsv_window_dump(root, verbose) do {} while (0)
 #endif
@@ -357,7 +410,7 @@ static inline int rsv_is_empty(struct ext2_reserve_window *rsv)
 void ext2_init_block_alloc_info(struct inode *inode)
 {
 	struct ext2_inode_info *ei = EXT2_I(inode);
-	struct ext2_block_alloc_info *block_i = ei->i_block_alloc_info;
+	struct ext2_block_alloc_info *block_i;
 	struct super_block *sb = inode->i_sb;
 
 	block_i = kmalloc(sizeof(*block_i), GFP_NOFS);
@@ -415,9 +468,9 @@ void ext2_discard_reservation(struct inode *inode)
 }
 
 /**
- * ext2_free_blocks_sb() -- Free given blocks and update quota and i_blocks
+ * ext2_free_blocks() -- Free given blocks and update quota and i_blocks
  * @inode:		inode
- * @block:		start physcial block to free
+ * @block:		start physical block to free
  * @count:		number of blocks to free
  */
 void ext2_free_blocks (struct inode * inode, unsigned long block,
@@ -474,16 +527,18 @@ do_more:
 	    in_range (block, le32_to_cpu(desc->bg_inode_table),
 		      sbi->s_itb_per_group) ||
 	    in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
-		      sbi->s_itb_per_group))
+		      sbi->s_itb_per_group)) {
 		ext2_error (sb, "ext2_free_blocks",
 			    "Freeing blocks in system zones - "
 			    "Block = %lu, count = %lu",
 			    block, count);
+		goto error_return;
+	}
 
 	for (i = 0, group_freed = 0; i < count; i++) {
 		if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
 						bit + i, bitmap_bh->b_data)) {
-			ext2_error(sb, __FUNCTION__,
+			ext2_error(sb, __func__,
 				"bit already cleared for block %lu", block + i);
 		} else {
 			group_freed++;
@@ -504,8 +559,11 @@ do_more:
 	}
 error_return:
 	brelse(bitmap_bh);
-	release_blocks(sb, freed);
-	DQUOT_FREE_BLOCK(inode, freed);
+	if (freed) {
+		percpu_counter_add(&sbi->s_freeblocks_counter, freed);
+		dquot_free_block_nodirty(inode, freed);
+		mark_inode_dirty(inode);
+	}
 }
 
 /**
@@ -580,10 +638,9 @@ find_next_usable_block(int start, struct buffer_head *bh, int maxblocks)
 	return here;
 }
 
-/*
+/**
  * ext2_try_to_allocate()
  * @sb:			superblock
- * @handle:		handle to this transaction
  * @group:		given allocation block group
  * @bitmap_bh:		bufferhead holds the block bitmap
  * @grp_goal:		given target block within the group
@@ -785,7 +842,7 @@ static int find_next_reservable_window(
 		rsv_window_remove(sb, my_rsv);
 
 	/*
-	 * Let's book the whole avaliable window for now.  We will check the
+	 * Let's book the whole available window for now.  We will check the
 	 * disk bitmap later and then, if there are free blocks then we adjust
 	 * the window size if it's larger than requested.
 	 * Otherwise, we will remove this node from the tree next time
@@ -1128,8 +1185,9 @@ static int ext2_has_free_blocks(struct ext2_sb_info *sbi)
 	free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
 	root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
 	if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
-		sbi->s_resuid != current->fsuid &&
-		(sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
+		!uid_eq(sbi->s_resuid, current_fsuid()) &&
+		(gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) ||
+		 !in_group_p (sbi->s_resgid))) {
 		return 0;
 	}
 	return 1;
@@ -1171,19 +1229,17 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
 	unsigned short windowsz = 0;
 	unsigned long ngroups;
 	unsigned long num = *count;
+	int ret;
 
 	*errp = -ENOSPC;
 	sb = inode->i_sb;
-	if (!sb) {
-		printk("ext2_new_blocks: nonexistent device");
-		return 0;
-	}
 
 	/*
 	 * Check quota for allocation of this block.
 	 */
-	if (DQUOT_ALLOC_BLOCK(inode, num)) {
-		*errp = -EDQUOT;
+	ret = dquot_alloc_block(inode, num);
+	if (ret) {
+		*errp = ret;
 		return 0;
 	}
 
@@ -1230,6 +1286,7 @@ retry_alloc:
 	 * turn off reservation for this allocation
 	 */
 	if (my_rsv && (free_blocks < windowsz)
+		&& (free_blocks > 0)
 		&& (rsv_is_empty(&my_rsv->rsv_window)))
 		my_rsv = NULL;
 
@@ -1250,8 +1307,8 @@ retry_alloc:
 	smp_rmb();
 
 	/*
-	 * Now search the rest of the groups.  We assume that 
-	 * i and gdp correctly point to the last group visited.
+	 * Now search the rest of the groups.  We assume that
+	 * group_no and gdp correctly point to the last group visited.
 	 */
 	for (bgi = 0; bgi < ngroups; bgi++) {
 		group_no++;
@@ -1263,11 +1320,17 @@ retry_alloc:
 
 		free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
 		/*
+		 * skip this group (and avoid loading bitmap) if there
+		 * are no free blocks
+		 */
+		if (!free_blocks)
+			continue;
+		/*
 		 * skip this group if the number of
 		 * free blocks is less than half of the reservation
 		 * window size.
 		 */
-		if (free_blocks <= (windowsz/2))
+		if (my_rsv && (free_blocks <= (windowsz/2)))
 			continue;
 
 		brelse(bitmap_bh);
@@ -1283,9 +1346,9 @@ retry_alloc:
 			goto allocated;
 	}
 	/*
-	 * We may end up a bogus ealier ENOSPC error due to
+	 * We may end up a bogus earlier ENOSPC error due to
 	 * filesystem is "full" of reservations, but
-	 * there maybe indeed free blocks avaliable on disk
+	 * there maybe indeed free blocks available on disk
 	 * In this case, we just forget about the reservations
 	 * just do block allocation as without reservations.
 	 */
@@ -1311,11 +1374,18 @@ allocated:
 	    in_range(ret_block, le32_to_cpu(gdp->bg_inode_table),
 		      EXT2_SB(sb)->s_itb_per_group) ||
 	    in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
-		      EXT2_SB(sb)->s_itb_per_group))
+		      EXT2_SB(sb)->s_itb_per_group)) {
 		ext2_error(sb, "ext2_new_blocks",
 			    "Allocating block in system zone - "
 			    "blocks from "E2FSBLK", length %lu",
 			    ret_block, num);
+		/*
+		 * ext2_try_to_allocate marked the blocks we allocated as in
+		 * use.  So we may want to selectively mark some of the blocks
+		 * as free
+		 */
+		goto retry_alloc;
+	}
 
 	performed_allocation = 1;
 
@@ -1336,8 +1406,11 @@ allocated:
 
 	*errp = 0;
 	brelse(bitmap_bh);
-	DQUOT_FREE_BLOCK(inode, *count-num);
-	*count = num;
+	if (num < *count) {
+		dquot_free_block_nodirty(inode, *count-num);
+		mark_inode_dirty(inode);
+		*count = num;
+	}
 	return ret_block;
 
 io_error:
@@ -1346,8 +1419,10 @@ out:
 	/*
 	 * Undo the block allocation
 	 */
-	if (!performed_allocation)
-		DQUOT_FREE_BLOCK(inode, *count);
+	if (!performed_allocation) {
+		dquot_free_block_nodirty(inode, *count);
+		mark_inode_dirty(inode);
+	}
 	brelse(bitmap_bh);
 	return 0;
 }
@@ -1361,19 +1436,9 @@ ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp)
 
 #ifdef EXT2FS_DEBUG
 
-static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
-
-unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars)
+unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars)
 {
-	unsigned int i;
-	unsigned long sum = 0;
-
-	if (!map)
-		return (0);
-	for (i = 0; i < numchars; i++)
-		sum += nibblemap[map->b_data[i] & 0xf] +
-			nibblemap[(map->b_data[i] >> 4) & 0xf];
-	return (sum);
+	return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars);
 }
 
 #endif  /*  EXT2FS_DEBUG  */
@@ -1466,9 +1531,6 @@ int ext2_bg_has_super(struct super_block *sb, int group)
  */
 unsigned long ext2_bg_num_gdb(struct super_block *sb, int group)
 {
-	if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
-	    !ext2_group_sparse(group))
-		return 0;
-	return EXT2_SB(sb)->s_gdb_count;
+	return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0;
 }