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| author | Baokun Li <libaokun1@huawei.com> | 2023-07-24 15:10:59 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-07-29 07:02:30 +0300 |
| commit | bedc5d34632c21b5adb8ca7143d4c1f794507e4c (patch) | |
| tree | 509df443f936c528b3735379b73c0e94e299f761 | |
| parent | bc056e7163ac7db945366de219745cf94f32a3e6 (diff) | |
| download | linux-bedc5d34632c21b5adb8ca7143d4c1f794507e4c.tar.xz | |
ext4: avoid overlapping preallocations due to overflow
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>
| -rw-r--r-- | fs/ext4/mballoc.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 86bce870dc5a..78a4a24e2f57 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4222,12 +4222,13 @@ 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); @@ -4236,7 +4237,7 @@ 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) @@ -4258,14 +4259,14 @@ 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; @@ -4284,7 +4285,7 @@ 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); @@ -4364,8 +4365,7 @@ 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); } @@ -4404,8 +4404,7 @@ 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; |