From: Baokun Li libaokun1@huawei.com
[ Upstream commit bedc5d34632c21b5adb8ca7143d4c1f794507e4c ]
Let's say we want to allocate 2 blocks starting from 4294966386, after predicting the file size, start is aligned to 4294965248, len is changed to 2048, then end = start + size = 0x100000000. Since end is of type ext4_lblk_t, i.e. uint, end is truncated to 0.
This causes (pa->pa_lstart >= end) to always hold when checking if the current extent to be allocated crosses already preallocated blocks, so the resulting ac_g_ex may cross already preallocated blocks. Hence we convert the end type to loff_t and use pa_logical_end() 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/20230724121059.11834-4-libaokun1@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/mballoc.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index f17c1573c2a65..6e88f58ec6bb8 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4036,12 +4036,13 @@ ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_
static inline void ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, - ext4_lblk_t start, ext4_lblk_t end) + ext4_lblk_t start, loff_t end) { struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); struct ext4_prealloc_space *tmp_pa; - ext4_lblk_t tmp_pa_start, tmp_pa_end; + ext4_lblk_t tmp_pa_start; + loff_t tmp_pa_end; struct rb_node *iter;
read_lock(&ei->i_prealloc_lock); @@ -4050,7 +4051,7 @@ ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, tmp_pa = rb_entry(iter, struct ext4_prealloc_space, pa_node.inode_node); tmp_pa_start = tmp_pa->pa_lstart; - tmp_pa_end = tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); + tmp_pa_end = pa_logical_end(sbi, tmp_pa);
spin_lock(&tmp_pa->pa_lock); if (tmp_pa->pa_deleted == 0) @@ -4072,14 +4073,14 @@ ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, */ static inline void ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, - ext4_lblk_t *start, ext4_lblk_t *end) + ext4_lblk_t *start, loff_t *end) { struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL; struct rb_node *iter; - ext4_lblk_t new_start, new_end; - ext4_lblk_t tmp_pa_start, tmp_pa_end, left_pa_end = -1, right_pa_start = -1; + ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1; + loff_t new_end, tmp_pa_end, left_pa_end = -1;
new_start = *start; new_end = *end; @@ -4098,7 +4099,7 @@ ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, tmp_pa = rb_entry(iter, struct ext4_prealloc_space, pa_node.inode_node); tmp_pa_start = tmp_pa->pa_lstart; - tmp_pa_end = tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); + tmp_pa_end = pa_logical_end(sbi, tmp_pa);
/* PA must not overlap original request */ spin_lock(&tmp_pa->pa_lock); @@ -4178,8 +4179,7 @@ ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, }
if (left_pa) { - left_pa_end = - left_pa->pa_lstart + EXT4_C2B(sbi, left_pa->pa_len); + left_pa_end = pa_logical_end(sbi, left_pa); BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical); }
@@ -4218,8 +4218,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); struct ext4_super_block *es = sbi->s_es; int bsbits, max; - ext4_lblk_t end; - loff_t size, start_off; + loff_t size, start_off, end; loff_t orig_size __maybe_unused; ext4_lblk_t start;