aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ext4/mballoc.c
diff options
context:
space:
mode:
authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2008-07-11 19:27:31 -0400
committerTheodore Ts'o <tytso@mit.edu>2008-07-11 19:27:31 -0400
commite7dfb2463e3c1b10c38372023e0186d25dec1fa6 (patch)
tree48e05520ccaf7e0c8a2f5bdfc9851069277a6a79 /fs/ext4/mballoc.c
parentf3b35f063e9a795495fe2f7a2fe55fab11f8ab12 (diff)
ext4: Fix mb_find_next_bit not to return larger than max
Some architectures implement ext4_find_next_bit and ext4_find_next_zero_bit in such a way that they return greater than max for some input values. Make sure mb_find_next_bit and mb_find_next_zero_bit return the right values. On 2.6.25 we have include/asm-x86/bitops_32.h static inline unsigned find_first_bit(const unsigned long *addr, unsigned size) { unsigned x = 0; while (x < size) { unsigned long val = *addr++; if (val) return __ffs(val) + x; x += (sizeof(*addr)<<3); } return x; } This can return value greater than size. Reported and fixed here for lustre https://bugzilla.lustre.org/show_bug.cgi?id=15932 https://bugzilla.lustre.org/attachment.cgi?id=17205 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/mballoc.c')
-rw-r--r--fs/ext4/mballoc.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index c9900aade150..ba3aad27f442 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -381,22 +381,28 @@ static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
381 381
382static inline int mb_find_next_zero_bit(void *addr, int max, int start) 382static inline int mb_find_next_zero_bit(void *addr, int max, int start)
383{ 383{
384 int fix = 0; 384 int fix = 0, ret, tmpmax;
385 addr = mb_correct_addr_and_bit(&fix, addr); 385 addr = mb_correct_addr_and_bit(&fix, addr);
386 max += fix; 386 tmpmax = max + fix;
387 start += fix; 387 start += fix;
388 388
389 return ext4_find_next_zero_bit(addr, max, start) - fix; 389 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
390 if (ret > max)
391 return max;
392 return ret;
390} 393}
391 394
392static inline int mb_find_next_bit(void *addr, int max, int start) 395static inline int mb_find_next_bit(void *addr, int max, int start)
393{ 396{
394 int fix = 0; 397 int fix = 0, ret, tmpmax;
395 addr = mb_correct_addr_and_bit(&fix, addr); 398 addr = mb_correct_addr_and_bit(&fix, addr);
396 max += fix; 399 tmpmax = max + fix;
397 start += fix; 400 start += fix;
398 401
399 return ext4_find_next_bit(addr, max, start) - fix; 402 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
403 if (ret > max)
404 return max;
405 return ret;
400} 406}
401 407
402static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) 408static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
@@ -3473,8 +3479,6 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
3473 if (bit >= end) 3479 if (bit >= end)
3474 break; 3480 break;
3475 next = mb_find_next_bit(bitmap_bh->b_data, end, bit); 3481 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
3476 if (next > end)
3477 next = end;
3478 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit + 3482 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
3479 le32_to_cpu(sbi->s_es->s_first_data_block); 3483 le32_to_cpu(sbi->s_es->s_first_data_block);
3480 mb_debug(" free preallocated %u/%u in group %u\n", 3484 mb_debug(" free preallocated %u/%u in group %u\n",