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authorBaokun Li2023-10-28 14:47:47 +0800
committerGreg Kroah-Hartman2023-11-02 09:35:32 +0100
commit495c4c58d684eb91bda6ce023019d1b1711ff07b (patch)
treee3b469f740c465a296fbfdd5eaafd10fe6661ce7 /fs
parentd022e4ea9c2f22a1ce425ae2af02a99cc4dc8587 (diff)
ext4: add two helper functions extent_logical_end() and pa_logical_end()
commit 43bbddc067883d94de7a43d5756a295439fbe37d upstream. When we use lstart + len to calculate the end of free extent or prealloc space, it may exceed the maximum value of 4294967295(0xffffffff) supported by ext4_lblk_t and cause overflow, which may lead to various problems. Therefore, we add two helper functions, extent_logical_end() and pa_logical_end(), to limit the type of end to loff_t, and also convert lstart to loff_t for calculation to avoid overflow. Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20230724121059.11834-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Baokun Li <libaokun1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/mballoc.c7
-rw-r--r--fs/ext4/mballoc.h14
2 files changed, 17 insertions, 4 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 3c8300e08f41..522d32d986e4 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4052,7 +4052,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
/* first, let's learn actual file size
* given current request is allocated */
- size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
+ size = extent_logical_end(sbi, &ac->ac_o_ex);
size = size << bsbits;
if (size < i_size_read(ac->ac_inode))
size = i_size_read(ac->ac_inode);
@@ -4407,8 +4407,7 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
/* all fields in this condition don't change,
* so we can skip locking for them */
if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
- ac->ac_o_ex.fe_logical >= (pa->pa_lstart +
- EXT4_C2B(sbi, pa->pa_len)))
+ ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, pa))
continue;
/* non-extent files can't have physical blocks past 2^32 */
@@ -5229,7 +5228,7 @@ static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
group_pa_eligible = sbi->s_mb_group_prealloc > 0;
inode_pa_eligible = true;
- size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len);
+ size = extent_logical_end(sbi, &ac->ac_o_ex);
isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
>> bsbits;
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index dcda2a943cee..00b3898df4a7 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -218,6 +218,20 @@ static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
(fex->fe_start << EXT4_SB(sb)->s_cluster_bits);
}
+static inline loff_t extent_logical_end(struct ext4_sb_info *sbi,
+ struct ext4_free_extent *fex)
+{
+ /* Use loff_t to avoid end exceeding ext4_lblk_t max. */
+ return (loff_t)fex->fe_logical + EXT4_C2B(sbi, fex->fe_len);
+}
+
+static inline loff_t pa_logical_end(struct ext4_sb_info *sbi,
+ struct ext4_prealloc_space *pa)
+{
+ /* Use loff_t to avoid end exceeding ext4_lblk_t max. */
+ return (loff_t)pa->pa_lstart + EXT4_C2B(sbi, pa->pa_len);
+}
+
typedef int (*ext4_mballoc_query_range_fn)(
struct super_block *sb,
ext4_group_t agno,