This is a note to let you know that I've just added the patch titled
ext4: add two helper functions extent_logical_end() and pa_logical_end()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-add-two-helper-functions-extent_logical_end-and-pa_logical_end.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From stable-owner@xxxxxxxxxxxxxxx Sat Oct 28 08:49:06 2023
From: Baokun Li <libaokun1@xxxxxxxxxx>
Date: Sat, 28 Oct 2023 14:53:29 +0800
Subject: ext4: add two helper functions extent_logical_end() and pa_logical_end()
To: <stable@xxxxxxxxxxxxxxx>
Cc: <gregkh@xxxxxxxxxxxxxxxxxxx>, <sashal@xxxxxxxxxx>, <tytso@xxxxxxx>, <jack@xxxxxxx>, <ritesh.list@xxxxxxxxx>, <patches@xxxxxxxxxxxxxxx>, <yangerkun@xxxxxxxxxx>, <libaokun1@xxxxxxxxxx>
Message-ID: <20231028065331.948339-1-libaokun1@xxxxxxxxxx>
From: Baokun Li <libaokun1@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230724121059.11834-2-libaokun1@xxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/mballoc.c | 7 +++----
fs/ext4/mballoc.h | 14 ++++++++++++++
2 files changed, 17 insertions(+), 4 deletions(-)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3124,7 +3124,7 @@ ext4_mb_normalize_request(struct ext4_al
/* 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);
@@ -3462,8 +3462,7 @@ ext4_mb_use_preallocated(struct ext4_all
/* 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 */
@@ -4234,7 +4233,7 @@ static void ext4_mb_group_or_file(struct
if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
return;
- 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;
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -199,6 +199,20 @@ static inline ext4_fsblk_t ext4_grp_offs
(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,
Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are
queue-5.4/ext4-avoid-overlapping-preallocations-due-to-overflow.patch
queue-5.4/ext4-fix-bug-in-ext4_mb_new_inode_pa-due-to-overflow.patch
queue-5.4/ext4-add-two-helper-functions-extent_logical_end-and-pa_logical_end.patch
