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From: "Theodore Ts'o" <tytso@MIT.EDU>
To: linux-kernel@vger.kernel.org
Cc: Avantika Mathur <mathur@us.ibm.com>, "Theodore Ts'o" <tytso@MIT.EDU>
Subject: [PATCH 06/49] ext4: fixes block group number being set to a negative value
Date: Mon, 21 Jan 2008 22:01:45 -0500	[thread overview]
Message-ID: <1200970948-17903-7-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <1200970948-17903-6-git-send-email-tytso@mit.edu>

From: Avantika Mathur <mathur@us.ibm.com>

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

Signed-off-by: Avantika Mathur <mathur@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
 fs/ext4/ialloc.c |  101 ++++++++++++++++++++++++++++-------------------------
 1 files changed, 53 insertions(+), 48 deletions(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 64dea86..7b5cfa6 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -260,12 +260,14 @@ error_return:
  * 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 @@ fallback:
 	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++) {
-- 
1.5.4.rc3.31.g1271-dirty


  reply	other threads:[~2008-01-22  3:22 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-22  3:01 ext4 merge plans for 2.6.25 Theodore Ts'o
2008-01-22  3:01 ` [PATCH 01/49] ext4: Support large blocksize up to PAGESIZE Theodore Ts'o
2008-01-22  3:01   ` [PATCH 02/49] ext4: Avoid rec_len overflow with 64KB block size Theodore Ts'o
2008-01-22  3:01     ` [PATCH 03/49] ext4: Introduce ext4_lblk_t Theodore Ts'o
2008-01-22  3:01       ` [PATCH 04/49] ext4 extents: remove unneeded casts Theodore Ts'o
2008-01-22  3:01         ` [PATCH 05/49] ext4: add ext4_group_t, and change all group variables to this type Theodore Ts'o
2008-01-22  3:01           ` Theodore Ts'o [this message]
2008-01-22  3:01             ` [PATCH 07/49] ext4: Introduce ext4_update_*_feature Theodore Ts'o
2008-01-22  3:01               ` [PATCH 08/49] ext4: Fix sparse warnings Theodore Ts'o
2008-01-22  3:01                 ` [PATCH 09/49] ext4: Rename i_file_acl to i_file_acl_lo Theodore Ts'o
2008-01-22  3:01                   ` [PATCH 10/49] ext4: Rename i_dir_acl to i_size_high Theodore Ts'o
2008-01-22  3:01                     ` [PATCH 11/49] ext4: Add support for 48 bit inode i_blocks Theodore Ts'o
2008-01-22  3:01                       ` [PATCH 12/49] ext4: Support large files Theodore Ts'o
2008-01-22  3:01                         ` [PATCH 13/49] ext4: different maxbytes functions for bitmap & extent files Theodore Ts'o
2008-01-22  3:01                           ` [PATCH 14/49] ext4: export iov_shorten from kernel for ext4's use Theodore Ts'o
2008-01-22  3:01                             ` [PATCH 15/49] ext4: store maxbytes for bitmapped files and return EFBIG as appropriate Theodore Ts'o
2008-01-22  3:01                               ` [PATCH 16/49] ext2: Fix the max file size for ext2 file system Theodore Ts'o
2008-01-22  3:01                                 ` [PATCH 17/49] ext3: Fix the max file size for ext3 " Theodore Ts'o
2008-01-22  3:01                                   ` [PATCH 18/49] ext4: sync up block group descriptor with e2fsprogs Theodore Ts'o
2008-01-22  3:01                                     ` [PATCH 19/49] ext4: Return after ext4_error in case of failures Theodore Ts'o
2008-01-22  3:01                                       ` [PATCH 20/49] ext4/super.c: fix #ifdef's (CONFIG_EXT4_* -> CONFIG_EXT4DEV_*) Theodore Ts'o
2008-01-22  3:02                                         ` [PATCH 21/49] ext4: fix oops on corrupted ext4 mount Theodore Ts'o
2008-01-22  3:02                                           ` [PATCH 22/49] ext4: Change the default behaviour on error Theodore Ts'o
2008-01-22  3:02                                             ` [PATCH 23/49] Add buffer head related helper functions Theodore Ts'o
2008-01-22  3:02                                               ` [PATCH 24/49] ext4: add block bitmap validation Theodore Ts'o
2008-01-22  3:02                                                 ` [PATCH 25/49] jbd2: Remove printk from J_ASSERT to preserve registers during BUG Theodore Ts'o
2008-01-22  3:02                                                   ` [PATCH 26/49] jbd2: Fix assertion failure in fs/jbd2/checkpoint.c Theodore Ts'o
2008-01-22  3:02                                                     ` [PATCH 27/49] ext4: Check for the correct error return from Theodore Ts'o
2008-01-22  3:02                                                       ` [PATCH 28/49] ext4: remove unused code from ext4_find_entry() Theodore Ts'o
2008-01-22  3:02                                                         ` [PATCH 29/49] ext4: Make ext4_get_blocks_wrap take the truncate_mutex early Theodore Ts'o
2008-01-22  3:02                                                           ` [PATCH 30/49] ext4: Convert truncate_mutex to read write semaphore Theodore Ts'o
2008-01-22  3:02                                                             ` [PATCH 31/49] ext4: Take read lock during overwrite case Theodore Ts'o
2008-01-22  3:02                                                               ` [PATCH 32/49] jbd2: jbd2 stats through procfs Theodore Ts'o
2008-01-22  3:02                                                                 ` [PATCH 33/49] ext4: Add the journal checksum feature Theodore Ts'o
2008-01-22  3:02                                                                   ` [PATCH 34/49] vfs: Add 64 bit i_version support Theodore Ts'o
2008-01-22  3:02                                                                     ` [PATCH 35/49] ext4: Add inode version support in ext4 Theodore Ts'o
2008-01-22  3:02                                                                       ` [PATCH 36/49] ext4: Add EXT4_IOC_MIGRATE ioctl Theodore Ts'o
2008-01-22  3:02                                                                         ` [PATCH 37/49] ext4: Fix ext4_show_options to show the correct mount options Theodore Ts'o
2008-01-22  3:02                                                                           ` [PATCH 38/49] ext4: fix up EXT4FS_DEBUG builds Theodore Ts'o
2008-01-22  3:02                                                                             ` [PATCH 39/49] ext4: Add ext4_find_next_bit() Theodore Ts'o
2008-01-22  3:02                                                                               ` [PATCH 40/49] ext4: Add new functions for searching extent tree Theodore Ts'o
2008-01-22  3:02                                                                                 ` [PATCH 41/49] ext4: Add multi block allocator for ext4 Theodore Ts'o
2008-01-22  3:02                                                                                   ` [PATCH 42/49] ext4: Enable the multiblock allocator by default Theodore Ts'o
2008-01-22  3:02                                                                                     ` [PATCH 43/49] ext4: Check for return value from sb_set_blocksize Theodore Ts'o
2008-01-22  3:02                                                                                       ` [PATCH 44/49] ext4: fix uniniatilized extent splitting error Theodore Ts'o
2008-01-22  3:02                                                                                         ` [PATCH 45/49] ext4: Use the ext4_ext_actual_len() helper function Theodore Ts'o
2008-01-22  3:02                                                                                           ` [PATCH 46/49] jbd2: add lockdep support Theodore Ts'o
2008-01-22  3:02                                                                                             ` [PATCH 47/49] jbd2: Mark jbd2 slabs as SLAB_TEMPORARY Theodore Ts'o
2008-01-22  3:02                                                                                               ` [PATCH 48/49] jbd2: Use round-jiffies() function for the "5 second" ext4/jbd2 wakeup Theodore Ts'o
2008-01-22  3:02                                                                                                 ` [PATCH 49/49] jbd2: sparse pointer use of zero as null Theodore Ts'o
2008-01-23 22:07                                                                                   ` [PATCH 41/49] ext4: Add multi block allocator for ext4 Andrew Morton
2008-01-23 23:20                                                                                     ` Andreas Dilger
2008-01-24  7:56                                                                                     ` Aneesh Kumar K.V
2008-01-24  9:04                                                                                       ` Aneesh Kumar K.V
2008-01-24 14:53                                                                                       ` Aneesh Kumar K.V
2008-01-28 18:45                                                                                   ` Eric Sandeen
2008-01-23 22:07                                                                         ` [PATCH 36/49] ext4: Add EXT4_IOC_MIGRATE ioctl Andrew Morton
2008-01-24  5:55                                                                           ` Aneesh Kumar K.V
2008-01-26  4:15                                                                             ` Theodore Tso
2008-01-26  8:42                                                                               ` Aneesh Kumar K.V
2008-01-23 22:07                                                                   ` [PATCH 33/49] ext4: Add the journal checksum feature Andrew Morton
2008-01-23 22:40                                                                     ` Andreas Dilger
2008-01-24 21:24                                                                     ` Mingming Cao
2008-02-01 20:50                                                                       ` Girish Shilamkar
2008-01-23 22:06                                                             ` [PATCH 30/49] ext4: Convert truncate_mutex to read write semaphore Andrew Morton
2008-01-24  5:29                                                               ` Aneesh Kumar K.V
2008-01-24 13:00                                                               ` Andy Whitcroft
2008-01-23 22:06                                                 ` [PATCH 24/49] ext4: add block bitmap validation Andrew Morton
2008-01-26 13:26                                                   ` Theodore Tso
2008-01-23 22:06                                               ` [PATCH 23/49] Add buffer head related helper functions Andrew Morton
2008-01-24  5:22                                                 ` Aneesh Kumar K.V
2008-01-24  8:53                                                   ` Andrew Morton
2008-01-23 12:43 ` ext4 merge plans for 2.6.25 Christoph Hellwig

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