Commit 2aa9fc4c authored by Avantika Mathur's avatar Avantika Mathur Committed by Theodore Ts'o
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ext4: fixes block group number being set to a negative value 



This patch fixes various places where the group number is set to a negative
value.

Signed-off-by: default avatarAvantika Mathur <mathur@us.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent fd2d4291

fs/ext4/ialloc.c

+53 −48
Original line number Diff line number Diff line
@@ -260,12 +260,14 @@ void ext4_free_inode (handle_t *handle, struct inode * inode) 
 * For other inodes, search forward from the parent directory\'s block

 * group to find a free inode.

 */

static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent)

static int find_group_dir(struct super_block *sb, struct inode *parent,

				ext4_group_t *best_group)

{

	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;

	unsigned int freei, avefreei;

	struct ext4_group_desc *desc, *best_desc = NULL;

	ext4_group_t group, best_group = -1;

	ext4_group_t group;

	int ret = -1;



	freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);

	avefreei = freei / ngroups;
@@ -279,11 +281,12 @@ static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent) 
		if (!best_desc ||

		    (le16_to_cpu(desc->bg_free_blocks_count) >

		     le16_to_cpu(best_desc->bg_free_blocks_count))) {

			best_group = group;

			*best_group = group;

			best_desc = desc;

			ret = 0;

		}

	}

	return best_group;

	return ret;

}



/*
@@ -314,8 +317,8 @@ static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent) 
#define INODE_COST 64

#define BLOCK_COST 256



static ext4_group_t find_group_orlov(struct super_block *sb,

				      struct inode *parent)

static int find_group_orlov(struct super_block *sb, struct inode *parent,

				ext4_group_t *group)

{

	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;

	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -328,7 +331,7 @@ static ext4_group_t find_group_orlov(struct super_block *sb, 
	unsigned int ndirs;

	int max_debt, max_dirs, min_inodes;

	ext4_grpblk_t min_blocks;

	ext4_group_t group = -1, i;

	ext4_group_t i;

	struct ext4_group_desc *desc;



	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
@@ -341,13 +344,14 @@ static ext4_group_t find_group_orlov(struct super_block *sb, 
	if ((parent == sb->s_root->d_inode) ||

	    (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {

		int best_ndir = inodes_per_group;

		ext4_group_t best_group = -1;

		ext4_group_t grp;

		int ret = -1;



		get_random_bytes(&group, sizeof(group));

		parent_group = (unsigned)group % ngroups;

		get_random_bytes(&grp, sizeof(grp));

		parent_group = (unsigned)grp % ngroups;

		for (i = 0; i < ngroups; i++) {

			group = (parent_group + i) % ngroups;

			desc = ext4_get_group_desc (sb, group, NULL);

			grp = (parent_group + i) % ngroups;

			desc = ext4_get_group_desc(sb, grp, NULL);

			if (!desc || !desc->bg_free_inodes_count)

				continue;

			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
@@ -356,11 +360,12 @@ static ext4_group_t find_group_orlov(struct super_block *sb, 
				continue;

			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)

				continue;

			best_group = group;

			*group = grp;

			ret = 0;

			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);

		}

		if (best_group >= 0)

			return best_group;

		if (ret == 0)

			return ret;

		goto fallback;

	}
@@ -381,8 +386,8 @@ static ext4_group_t find_group_orlov(struct super_block *sb, 
		max_debt = 1;



	for (i = 0; i < ngroups; i++) {

		group = (parent_group + i) % ngroups;

		desc = ext4_get_group_desc (sb, group, NULL);

		*group = (parent_group + i) % ngroups;

		desc = ext4_get_group_desc(sb, *group, NULL);

		if (!desc || !desc->bg_free_inodes_count)

			continue;

		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
@@ -391,17 +396,16 @@ static ext4_group_t find_group_orlov(struct super_block *sb, 
			continue;

		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)

			continue;

		return group;

		return 0;

	}



fallback:

	for (i = 0; i < ngroups; i++) {

		group = (parent_group + i) % ngroups;

		desc = ext4_get_group_desc (sb, group, NULL);

		if (!desc || !desc->bg_free_inodes_count)

			continue;

		if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)

			return group;

		*group = (parent_group + i) % ngroups;

		desc = ext4_get_group_desc(sb, *group, NULL);

		if (desc && desc->bg_free_inodes_count &&

			le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)

			return 0;

	}



	if (avefreei) {
@@ -416,22 +420,22 @@ static ext4_group_t find_group_orlov(struct super_block *sb, 
	return -1;

}



static ext4_group_t find_group_other(struct super_block *sb,

					struct inode *parent)

static int find_group_other(struct super_block *sb, struct inode *parent,

				ext4_group_t *group)

{

	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;

	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;

	struct ext4_group_desc *desc;

	ext4_group_t group, i;

	ext4_group_t i;



	/*

	 * Try to place the inode in its parent directory

	 */

	group = parent_group;

	desc = ext4_get_group_desc (sb, group, NULL);

	*group = parent_group;

	desc = ext4_get_group_desc(sb, *group, NULL);

	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&

			le16_to_cpu(desc->bg_free_blocks_count))

		return group;

		return 0;



	/*

	 * We're going to place this inode in a different blockgroup from its
@@ -442,33 +446,33 @@ static ext4_group_t find_group_other(struct super_block *sb, 
	 *

	 * So add our directory's i_ino into the starting point for the hash.

	 */

	group = (group + parent->i_ino) % ngroups;

	*group = (*group + parent->i_ino) % ngroups;



	/*

	 * Use a quadratic hash to find a group with a free inode and some free

	 * blocks.

	 */

	for (i = 1; i < ngroups; i <<= 1) {

		group += i;

		if (group >= ngroups)

			group -= ngroups;

		desc = ext4_get_group_desc (sb, group, NULL);

		*group += i;

		if (*group >= ngroups)

			*group -= ngroups;

		desc = ext4_get_group_desc(sb, *group, NULL);

		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&

				le16_to_cpu(desc->bg_free_blocks_count))

			return group;

			return 0;

	}



	/*

	 * That failed: try linear search for a free inode, even if that group

	 * has no free blocks.

	 */

	group = parent_group;

	*group = parent_group;

	for (i = 0; i < ngroups; i++) {

		if (++group >= ngroups)

			group = 0;

		desc = ext4_get_group_desc (sb, group, NULL);

		if (++*group >= ngroups)

			*group = 0;

		desc = ext4_get_group_desc(sb, *group, NULL);

		if (desc && le16_to_cpu(desc->bg_free_inodes_count))

			return group;

			return 0;

	}



	return -1;
@@ -489,16 +493,17 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode) 
	struct super_block *sb;

	struct buffer_head *bitmap_bh = NULL;

	struct buffer_head *bh2;

	ext4_group_t group;

	ext4_group_t group = 0;

	unsigned long ino = 0;

	struct inode * inode;

	struct ext4_group_desc * gdp = NULL;

	struct ext4_super_block * es;

	struct ext4_inode_info *ei;

	struct ext4_sb_info *sbi;

	int err = 0;

	int ret2, err = 0;

	struct inode *ret;

	int i, free = 0;

	ext4_group_t i;

	int free = 0;



	/* Cannot create files in a deleted directory */

	if (!dir || !dir->i_nlink)
@@ -514,14 +519,14 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode) 
	es = sbi->s_es;

	if (S_ISDIR(mode)) {

		if (test_opt (sb, OLDALLOC))

			group = find_group_dir(sb, dir);

			ret2 = find_group_dir(sb, dir, &group);

		else

			group = find_group_orlov(sb, dir);

			ret2 = find_group_orlov(sb, dir, &group);

	} else

		group = find_group_other(sb, dir);

		ret2 = find_group_other(sb, dir, &group);



	err = -ENOSPC;

	if (group == -1)

	if (ret2 == -1)

		goto out;



	for (i = 0; i < sbi->s_groups_count; i++) {