kernel.git/fs/ext4/mballoc.c, branch linux-6.5.y

ext4: do not let fstrim block system suspend

2023-10-06T11:15:46Z

[ Upstream commit 5229a658f6453362fbb9da6bf96872ef25a7097e ] Len Brown has reported that system suspend sometimes fail due to inability to freeze a task working in ext4_trim_fs() for one minute. Trimming a large filesystem on a disk that slowly processes discard requests can indeed take a long time. Since discard is just an advisory call, it is perfectly fine to interrupt it at any time and the return number of discarded blocks until that moment. Do that when we detect the task is being frozen. Cc: stable@kernel.org Reported-by: Len Brown Suggested-by: Dave Chinner References: https://bugzilla.kernel.org/show_bug.cgi?id=216322 Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230913150504.9054-2-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: move setting of trimmed bit into ext4_try_to_trim_range()

2023-10-06T11:15:46Z

[ Upstream commit 45e4ab320c9b5fa67b1fc3b6a9b381cfcc0c8488 ] Currently we set the group's trimmed bit in ext4_trim_all_free() based on return value of ext4_try_to_trim_range(). However when we will want to abort trimming because of suspend attempt, we want to return success from ext4_try_to_trim_range() but not set the trimmed bit. Instead implementing awkward propagation of this information, just move setting of trimmed bit into ext4_try_to_trim_range() when the whole group is trimmed. Cc: stable@kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230913150504.9054-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: replace the traditional ternary conditional operator with with max()/min()

2023-10-06T11:15:45Z

[ Upstream commit de8bf0e5ee7482585450357c6d4eddec8efc5cb7 ] Replace the traditional ternary conditional operator with with max()/min() Signed-off-by: Kemeng Shi Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230801143204.2284343-7-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Stable-dep-of: 45e4ab320c9b ("ext4: move setting of trimmed bit into ext4_try_to_trim_range()") Signed-off-by: Sasha Levin

ext4: fix BUG in ext4_mb_new_inode_pa() due to overflow

2023-09-23T09:14:30Z

[ Upstream commit bc056e7163ac7db945366de219745cf94f32a3e6 ] When we calculate the end position of ext4_free_extent, this position may be exactly where ext4_lblk_t (i.e. uint) overflows. For example, if ac_g_ex.fe_logical is 4294965248 and ac_orig_goal_len is 2048, then the computed end is 0x100000000, which is 0. If ac->ac_o_ex.fe_logical is not the first case of adjusting the best extent, that is, new_bex_end > 0, the following BUG_ON will be triggered: ========================================================= kernel BUG at fs/ext4/mballoc.c:5116! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 673 Comm: xfs_io Tainted: G E 6.5.0-rc1+ #279 RIP: 0010:ext4_mb_new_inode_pa+0xc5/0x430 Call Trace: ext4_mb_use_best_found+0x203/0x2f0 ext4_mb_try_best_found+0x163/0x240 ext4_mb_regular_allocator+0x158/0x1550 ext4_mb_new_blocks+0x86a/0xe10 ext4_ext_map_blocks+0xb0c/0x13a0 ext4_map_blocks+0x2cd/0x8f0 ext4_iomap_begin+0x27b/0x400 iomap_iter+0x222/0x3d0 __iomap_dio_rw+0x243/0xcb0 iomap_dio_rw+0x16/0x80 ========================================================= A simple reproducer demonstrating the problem: mkfs.ext4 -F /dev/sda -b 4096 100M mount /dev/sda /tmp/test fallocate -l1M /tmp/test/tmp fallocate -l10M /tmp/test/file fallocate -i -o 1M -l16777203M /tmp/test/file fsstress -d /tmp/test -l 0 -n 100000 -p 8 & sleep 10 && killall -9 fsstress rm -f /tmp/test/tmp xfs_io -c "open -ad /tmp/test/file" -c "pwrite -S 0xff 0 8192" We simply refactor the logic for adjusting the best extent by adding a temporary ext4_free_extent ex and use extent_logical_end() to avoid overflow, which also simplifies the code. Cc: stable@kernel.org # 6.4 Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()") Signed-off-by: Baokun Li Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230724121059.11834-3-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: avoid overlapping preallocations due to overflow

2023-09-23T09:14:26Z

[ 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 Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230724121059.11834-4-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: add two helper functions extent_logical_end() and pa_logical_end()

2023-09-23T09:14:26Z

[ Upstream commit 43bbddc067883d94de7a43d5756a295439fbe37d ] 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 Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230724121059.11834-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: avoid potential data overflow in next_linear_group

2023-09-13T07:53:29Z

[ Upstream commit 60c672b7f2d1e5dd1774f2399b355c9314e709f8 ] ngroups is ext4_group_t (unsigned int) while next_linear_group treat it in int. If ngroups is bigger than max number described by int, it will be treat as a negative number. Then "return group + 1 >= ngroups ? 0 : group + 1;" may keep returning 0. Switch int to ext4_group_t in next_linear_group to fix the overflow. Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning") Signed-off-by: Kemeng Shi Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230801143204.2284343-3-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: correct grp validation in ext4_mb_good_group

2023-09-13T07:53:29Z

[ Upstream commit a9ce5993a0f5c0887c8a1b4ffa3b8046fbcfdc93 ] Group corruption check will access memory of grp and will trigger kernel crash if grp is NULL. So do NULL check before corruption check. Fixes: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail") Signed-off-by: Kemeng Shi Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230801143204.2284343-2-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: fix rbtree traversal bug in ext4_mb_use_preallocated

2023-07-23T12:21:14Z

During allocations, while looking for preallocations(PA) in the per inode rbtree, we can't do a direct traversal of the tree because ext4_mb_discard_group_preallocation() can paralelly mark the pa deleted and that can cause direct traversal to skip some entries. This was leading to a BUG_ON() being hit [1] when we missed a PA that could satisfy our request and ultimately tried to create a new PA that would overlap with the missed one. To makes sure we handle that case while still keeping the performance of the rbtree, we make use of the fact that the only pa that could possibly overlap the original goal start is the one that satisfies the below conditions: 1. It must have it's logical start immediately to the left of (ie less than) original logical start. 2. It must not be deleted To find this pa we use the following traversal method: 1. Descend into the rbtree normally to find the immediate neighboring PA. Here we keep descending irrespective of if the PA is deleted or if it overlaps with our request etc. The goal is to find an immediately adjacent PA. 2. If the found PA is on right of original goal, use rb_prev() to find the left adjacent PA. 3. Check if this PA is deleted and keep moving left with rb_prev() until a non deleted PA is found. 4. This is the PA we are looking for. Now we can check if it can satisfy the original request and proceed accordingly. This approach also takes care of having deleted PAs in the tree. (While we are at it, also fix a possible overflow bug in calculating the end of a PA) [1] https://lore.kernel.org/linux-ext4/CA+G9fYv2FRpLqBZf34ZinR8bU2_ZRAUOjKAD3+tKRFaEQHtt8Q@mail.gmail.com/ Cc: stable@kernel.org # 6.4 Fixes: 3872778664e3 ("ext4: Use rbtrees to manage PAs instead of inode i_prealloc_list") Signed-off-by: Ojaswin Mujoo Reported-by: Naresh Kamboju Reviewed-by: Ritesh Harjani (IBM) ritesh.list@gmail.com Tested-by: Ritesh Harjani (IBM) ritesh.list@gmail.com Link: https://lore.kernel.org/r/edd2efda6a83e6343c5ace9deea44813e71dbe20.1690045963.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o

ext4: fix off by one issue in ext4_mb_choose_next_group_best_avail()

2023-07-23T12:21:14Z

In ext4_mb_choose_next_group_best_avail(), we want the start order to be 1 less than goal length and the min_order to be, at max, 1 more than the original length. This commit fixes an off by one issue that arose due to the fact that 1 << fls(n) > (n). After all the processing: order = 1 order below goal len min_order = maximum of the three:- - order - trim_order - 1 order below B2C(s_stripe) - 1 order above original len Cc: stable@kernel.org Fixes: 33122aa930 ("ext4: Add allocation criteria 1.5 (CR1_5)") Signed-off-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20230609103403.112807-1-ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o