提交 2aa9fc4c 编写于 作者: A Avantika Mathur 提交者: Theodore Ts'o

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: NAvantika Mathur <mathur@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
上级 fd2d4291
...@@ -260,12 +260,14 @@ void ext4_free_inode (handle_t *handle, struct inode * inode) ...@@ -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 * For other inodes, search forward from the parent directory\'s block
* group to find a free inode. * 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; ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
unsigned int freei, avefreei; unsigned int freei, avefreei;
struct ext4_group_desc *desc, *best_desc = NULL; 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); freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
avefreei = freei / ngroups; avefreei = freei / ngroups;
...@@ -279,11 +281,12 @@ static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent) ...@@ -279,11 +281,12 @@ static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent)
if (!best_desc || if (!best_desc ||
(le16_to_cpu(desc->bg_free_blocks_count) > (le16_to_cpu(desc->bg_free_blocks_count) >
le16_to_cpu(best_desc->bg_free_blocks_count))) { le16_to_cpu(best_desc->bg_free_blocks_count))) {
best_group = group; *best_group = group;
best_desc = desc; 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) ...@@ -314,8 +317,8 @@ static ext4_group_t find_group_dir(struct super_block *sb, struct inode *parent)
#define INODE_COST 64 #define INODE_COST 64
#define BLOCK_COST 256 #define BLOCK_COST 256
static ext4_group_t find_group_orlov(struct super_block *sb, static int find_group_orlov(struct super_block *sb, struct inode *parent,
struct inode *parent) ext4_group_t *group)
{ {
ext4_group_t parent_group = EXT4_I(parent)->i_block_group; ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_sb_info *sbi = EXT4_SB(sb);
...@@ -328,7 +331,7 @@ static ext4_group_t find_group_orlov(struct super_block *sb, ...@@ -328,7 +331,7 @@ static ext4_group_t find_group_orlov(struct super_block *sb,
unsigned int ndirs; unsigned int ndirs;
int max_debt, max_dirs, min_inodes; int max_debt, max_dirs, min_inodes;
ext4_grpblk_t min_blocks; ext4_grpblk_t min_blocks;
ext4_group_t group = -1, i; ext4_group_t i;
struct ext4_group_desc *desc; struct ext4_group_desc *desc;
freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
...@@ -341,13 +344,14 @@ static ext4_group_t find_group_orlov(struct super_block *sb, ...@@ -341,13 +344,14 @@ static ext4_group_t find_group_orlov(struct super_block *sb,
if ((parent == sb->s_root->d_inode) || if ((parent == sb->s_root->d_inode) ||
(EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) { (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
int best_ndir = inodes_per_group; 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)); get_random_bytes(&grp, sizeof(grp));
parent_group = (unsigned)group % ngroups; parent_group = (unsigned)grp % ngroups;
for (i = 0; i < ngroups; i++) { for (i = 0; i < ngroups; i++) {
group = (parent_group + i) % ngroups; grp = (parent_group + i) % ngroups;
desc = ext4_get_group_desc (sb, group, NULL); desc = ext4_get_group_desc(sb, grp, NULL);
if (!desc || !desc->bg_free_inodes_count) if (!desc || !desc->bg_free_inodes_count)
continue; continue;
if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir) 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, ...@@ -356,11 +360,12 @@ static ext4_group_t find_group_orlov(struct super_block *sb,
continue; continue;
if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb) if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
continue; continue;
best_group = group; *group = grp;
ret = 0;
best_ndir = le16_to_cpu(desc->bg_used_dirs_count); best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
} }
if (best_group >= 0) if (ret == 0)
return best_group; return ret;
goto fallback; goto fallback;
} }
...@@ -381,8 +386,8 @@ static ext4_group_t find_group_orlov(struct super_block *sb, ...@@ -381,8 +386,8 @@ static ext4_group_t find_group_orlov(struct super_block *sb,
max_debt = 1; max_debt = 1;
for (i = 0; i < ngroups; i++) { for (i = 0; i < ngroups; i++) {
group = (parent_group + i) % ngroups; *group = (parent_group + i) % ngroups;
desc = ext4_get_group_desc (sb, group, NULL); desc = ext4_get_group_desc(sb, *group, NULL);
if (!desc || !desc->bg_free_inodes_count) if (!desc || !desc->bg_free_inodes_count)
continue; continue;
if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs) 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, ...@@ -391,17 +396,16 @@ static ext4_group_t find_group_orlov(struct super_block *sb,
continue; continue;
if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks) if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
continue; continue;
return group; return 0;
} }
fallback: fallback:
for (i = 0; i < ngroups; i++) { for (i = 0; i < ngroups; i++) {
group = (parent_group + i) % ngroups; *group = (parent_group + i) % ngroups;
desc = ext4_get_group_desc (sb, group, NULL); desc = ext4_get_group_desc(sb, *group, NULL);
if (!desc || !desc->bg_free_inodes_count) if (desc && desc->bg_free_inodes_count &&
continue; le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei) return 0;
return group;
} }
if (avefreei) { if (avefreei) {
...@@ -416,22 +420,22 @@ static ext4_group_t find_group_orlov(struct super_block *sb, ...@@ -416,22 +420,22 @@ static ext4_group_t find_group_orlov(struct super_block *sb,
return -1; return -1;
} }
static ext4_group_t find_group_other(struct super_block *sb, static int find_group_other(struct super_block *sb, struct inode *parent,
struct inode *parent) ext4_group_t *group)
{ {
ext4_group_t parent_group = EXT4_I(parent)->i_block_group; ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
struct ext4_group_desc *desc; struct ext4_group_desc *desc;
ext4_group_t group, i; ext4_group_t i;
/* /*
* Try to place the inode in its parent directory * Try to place the inode in its parent directory
*/ */
group = parent_group; *group = parent_group;
desc = ext4_get_group_desc (sb, group, NULL); desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && le16_to_cpu(desc->bg_free_inodes_count) && if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
le16_to_cpu(desc->bg_free_blocks_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 * 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, ...@@ -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. * 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 * Use a quadratic hash to find a group with a free inode and some free
* blocks. * blocks.
*/ */
for (i = 1; i < ngroups; i <<= 1) { for (i = 1; i < ngroups; i <<= 1) {
group += i; *group += i;
if (group >= ngroups) if (*group >= ngroups)
group -= ngroups; *group -= ngroups;
desc = ext4_get_group_desc (sb, group, NULL); desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && le16_to_cpu(desc->bg_free_inodes_count) && if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
le16_to_cpu(desc->bg_free_blocks_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 * That failed: try linear search for a free inode, even if that group
* has no free blocks. * has no free blocks.
*/ */
group = parent_group; *group = parent_group;
for (i = 0; i < ngroups; i++) { for (i = 0; i < ngroups; i++) {
if (++group >= ngroups) if (++*group >= ngroups)
group = 0; *group = 0;
desc = ext4_get_group_desc (sb, group, NULL); desc = ext4_get_group_desc(sb, *group, NULL);
if (desc && le16_to_cpu(desc->bg_free_inodes_count)) if (desc && le16_to_cpu(desc->bg_free_inodes_count))
return group; return 0;
} }
return -1; return -1;
...@@ -489,16 +493,17 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode) ...@@ -489,16 +493,17 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
struct super_block *sb; struct super_block *sb;
struct buffer_head *bitmap_bh = NULL; struct buffer_head *bitmap_bh = NULL;
struct buffer_head *bh2; struct buffer_head *bh2;
ext4_group_t group; ext4_group_t group = 0;
unsigned long ino = 0; unsigned long ino = 0;
struct inode * inode; struct inode * inode;
struct ext4_group_desc * gdp = NULL; struct ext4_group_desc * gdp = NULL;
struct ext4_super_block * es; struct ext4_super_block * es;
struct ext4_inode_info *ei; struct ext4_inode_info *ei;
struct ext4_sb_info *sbi; struct ext4_sb_info *sbi;
int err = 0; int ret2, err = 0;
struct inode *ret; struct inode *ret;
int i, free = 0; ext4_group_t i;
int free = 0;
/* Cannot create files in a deleted directory */ /* Cannot create files in a deleted directory */
if (!dir || !dir->i_nlink) if (!dir || !dir->i_nlink)
...@@ -514,14 +519,14 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode) ...@@ -514,14 +519,14 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
es = sbi->s_es; es = sbi->s_es;
if (S_ISDIR(mode)) { if (S_ISDIR(mode)) {
if (test_opt (sb, OLDALLOC)) if (test_opt (sb, OLDALLOC))
group = find_group_dir(sb, dir); ret2 = find_group_dir(sb, dir, &group);
else else
group = find_group_orlov(sb, dir); ret2 = find_group_orlov(sb, dir, &group);
} else } else
group = find_group_other(sb, dir); ret2 = find_group_other(sb, dir, &group);
err = -ENOSPC; err = -ENOSPC;
if (group == -1) if (ret2 == -1)
goto out; goto out;
for (i = 0; i < sbi->s_groups_count; i++) { for (i = 0; i < sbi->s_groups_count; i++) {
......
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