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ext4: fix potential NULL dereference while tracing

The allocation_context pointer can be NULL.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2010-07-27 11:56:04 -04:00
parent 89eeddf033
commit e5880d76ae
2 changed files with 14 additions and 10 deletions

View file

@ -3575,7 +3575,7 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
trace_ext4_mballoc_discard(ac); trace_ext4_mballoc_discard(ac);
} }
trace_ext4_mb_release_inode_pa(ac, pa, grp_blk_start + bit, trace_ext4_mb_release_inode_pa(sb, ac, pa, grp_blk_start + bit,
next - bit); next - bit);
mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
bit = next + 1; bit = next + 1;
@ -3606,7 +3606,7 @@ ext4_mb_release_group_pa(struct ext4_buddy *e4b,
ext4_group_t group; ext4_group_t group;
ext4_grpblk_t bit; ext4_grpblk_t bit;
trace_ext4_mb_release_group_pa(ac, pa); trace_ext4_mb_release_group_pa(sb, ac, pa);
BUG_ON(pa->pa_deleted == 0); BUG_ON(pa->pa_deleted == 0);
ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
BUG_ON(group != e4b->bd_group && pa->pa_len != 0); BUG_ON(group != e4b->bd_group && pa->pa_len != 0);

View file

@ -395,11 +395,12 @@ DEFINE_EVENT(ext4__mb_new_pa, ext4_mb_new_group_pa,
); );
TRACE_EVENT(ext4_mb_release_inode_pa, TRACE_EVENT(ext4_mb_release_inode_pa,
TP_PROTO(struct ext4_allocation_context *ac, TP_PROTO(struct super_block *sb,
struct ext4_allocation_context *ac,
struct ext4_prealloc_space *pa, struct ext4_prealloc_space *pa,
unsigned long long block, unsigned int count), unsigned long long block, unsigned int count),
TP_ARGS(ac, pa, block, count), TP_ARGS(sb, ac, pa, block, count),
TP_STRUCT__entry( TP_STRUCT__entry(
__field( dev_t, dev ) __field( dev_t, dev )
@ -410,8 +411,9 @@ TRACE_EVENT(ext4_mb_release_inode_pa,
), ),
TP_fast_assign( TP_fast_assign(
__entry->dev = ac->ac_sb->s_dev; __entry->dev = sb->s_dev;
__entry->ino = ac->ac_inode->i_ino; __entry->ino = (ac && ac->ac_inode) ?
ac->ac_inode->i_ino : 0;
__entry->block = block; __entry->block = block;
__entry->count = count; __entry->count = count;
), ),
@ -422,10 +424,11 @@ TRACE_EVENT(ext4_mb_release_inode_pa,
); );
TRACE_EVENT(ext4_mb_release_group_pa, TRACE_EVENT(ext4_mb_release_group_pa,
TP_PROTO(struct ext4_allocation_context *ac, TP_PROTO(struct super_block *sb,
struct ext4_allocation_context *ac,
struct ext4_prealloc_space *pa), struct ext4_prealloc_space *pa),
TP_ARGS(ac, pa), TP_ARGS(sb, ac, pa),
TP_STRUCT__entry( TP_STRUCT__entry(
__field( dev_t, dev ) __field( dev_t, dev )
@ -436,8 +439,9 @@ TRACE_EVENT(ext4_mb_release_group_pa,
), ),
TP_fast_assign( TP_fast_assign(
__entry->dev = ac->ac_sb->s_dev; __entry->dev = sb->s_dev;
__entry->ino = ac->ac_inode->i_ino; __entry->ino = (ac && ac->ac_inode) ?
ac->ac_inode->i_ino : 0;
__entry->pa_pstart = pa->pa_pstart; __entry->pa_pstart = pa->pa_pstart;
__entry->pa_len = pa->pa_len; __entry->pa_len = pa->pa_len;
), ),