linux.git/fs/f2fs/extent_cache.c, branch for-next

f2fs: add a sysfs node to limit max read extent count per-inode

2024-11-23T15:48:13+00:00

Quoted:
"at this time, there are still 1086911 extent nodes in this zombie
extent tree that need to be cleaned up.

crash_arm64_sprd_v8.0.3++> extent_tree.node_cnt ffffff80896cc500
  node_cnt = {
    counter = 1086911
  },
"

As reported by Xiuhong, there will be a huge number of extent nodes
in extent tree, it may potentially cause:
- slab memory fragments
- extreme long time shrink on extent tree
- low mapping efficiency

Let's add a sysfs node to limit max read extent count for each inode,
by default, value of this threshold is 10240, it can be updated
according to user's requirement.

Reported-by: Xiuhong Wang 
Closes: https://lore.kernel.org/linux-f2fs-devel/20241112110627.1314632-1-xiuhong.wang@unisoc.com/
Signed-off-by: Xiuhong Wang 
Signed-off-by: Zhiguo Niu 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix to shrink read extent node in batches

2024-11-21T16:16:54+00:00

We use rwlock to protect core structure data of extent tree during
its shrink, however, if there is a huge number of extent nodes in
extent tree, during shrink of extent tree, it may hold rwlock for
a very long time, which may trigger kernel hang issue.

This patch fixes to shrink read extent node in batches, so that,
critical region of the rwlock can be shrunk to avoid its extreme
long time hold.

Reported-by: Xiuhong Wang 
Closes: https://lore.kernel.org/linux-f2fs-devel/20241112110627.1314632-1-xiuhong.wang@unisoc.com/
Signed-off-by: Xiuhong Wang 
Signed-off-by: Zhiguo Niu 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: introduce device aliasing file

2024-11-01T01:19:00+00:00

F2FS should understand how the device aliasing file works and support
deleting the file after use. A device aliasing file can be created by
mkfs.f2fs tool and it can map the whole device with an extent, not
using node blocks. The file space should be pinned and normally used for
read-only usages.

Signed-off-by: Daeho Jeong 
Signed-off-by: Chao Yu 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix several potential integer overflows in file offsets

2024-08-05T20:18:35+00:00

When dealing with large extents and calculating file offsets by
summing up according extent offsets and lengths of unsigned int type,
one may encounter possible integer overflow if the values are
big enough.

Prevent this from happening by expanding one of the addends to
(pgoff_t) type.

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: d323d005ac4a ("f2fs: support file defragment")
Cc: stable@vger.kernel.org
Signed-off-by: Nikita Zhandarovich 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix to cover read extent cache access with lock

2024-06-12T15:46:03+00:00

syzbot reports a f2fs bug as below:

BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097

CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
 do_read_inode fs/f2fs/inode.c:509 [inline]
 f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560
 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
 do_handle_to_path fs/fhandle.c:155 [inline]
 handle_to_path fs/fhandle.c:210 [inline]
 do_handle_open+0x495/0x650 fs/fhandle.c:226
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

We missed to cover sanity_check_extent_cache() w/ extent cache lock,
so, below race case may happen, result in use after free issue.

- f2fs_iget
 - do_read_inode
  - f2fs_init_read_extent_tree
  : add largest extent entry in to cache
					- shrink
					 - f2fs_shrink_read_extent_tree
					  - __shrink_extent_tree
					   - __detach_extent_node
					   : drop largest extent entry
  - sanity_check_extent_cache
  : access et->largest w/o lock

let's refactor sanity_check_extent_cache() to avoid extent cache access
and call it before f2fs_init_read_extent_tree() to fix this issue.

Reported-by: syzbot+74ebe2104433e9dc610d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/00000000000009beea061740a531@google.com
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: unify the error handling of f2fs_is_valid_blkaddr

2024-03-13T01:25:17+00:00

There are some cases of f2fs_is_valid_blkaddr not handled as
ERROR_INVALID_BLKADDR,so unify the error handling about all of
f2fs_is_valid_blkaddr.
Do f2fs_handle_error in __f2fs_is_valid_blkaddr for cleanup.

Signed-off-by: Zhiguo Niu 
Signed-off-by: Chao Yu 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: split initial and dynamic conditions for extent_cache

2023-09-12T20:49:33+00:00

Let's allocate the extent_cache tree without dynamic conditions to avoid a
missing condition causing a panic as below.

 # create a file w/ a compressed flag
 # disable the compression
 # panic while updating extent_cache

F2FS-fs (dm-64): Swapfile: last extent is not aligned to section
F2FS-fs (dm-64): Swapfile (3) is not align to section: 1) creat(), 2) ioctl(F2FS_IOC_SET_PIN_FILE), 3) fallocate(2097152 * N)
Adding 124996k swap on ./swap-file.  Priority:0 extents:2 across:17179494468k
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write out/common/include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in atomic_try_cmpxchg_acquire out/common/include/asm-generic/atomic-instrumented.h:705 [inline]
BUG: KASAN: null-ptr-deref in queued_write_lock out/common/include/asm-generic/qrwlock.h:92 [inline]
BUG: KASAN: null-ptr-deref in __raw_write_lock out/common/include/linux/rwlock_api_smp.h:211 [inline]
BUG: KASAN: null-ptr-deref in _raw_write_lock+0x5a/0x110 out/common/kernel/locking/spinlock.c:295
Write of size 4 at addr 0000000000000030 by task syz-executor154/3327

CPU: 0 PID: 3327 Comm: syz-executor154 Tainted: G           O      5.10.185 #1
Hardware name: emulation qemu-x86/qemu-x86, BIOS 2023.01-21885-gb3cc1cd24d 01/01/2023
Call Trace:
 __dump_stack out/common/lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x17e/0x1c4 out/common/lib/dump_stack.c:118
 __kasan_report+0x16c/0x260 out/common/mm/kasan/report.c:415
 kasan_report+0x51/0x70 out/common/mm/kasan/report.c:428
 kasan_check_range+0x2f3/0x340 out/common/mm/kasan/generic.c:186
 __kasan_check_write+0x14/0x20 out/common/mm/kasan/shadow.c:37
 instrument_atomic_read_write out/common/include/linux/instrumented.h:101 [inline]
 atomic_try_cmpxchg_acquire out/common/include/asm-generic/atomic-instrumented.h:705 [inline]
 queued_write_lock out/common/include/asm-generic/qrwlock.h:92 [inline]
 __raw_write_lock out/common/include/linux/rwlock_api_smp.h:211 [inline]
 _raw_write_lock+0x5a/0x110 out/common/kernel/locking/spinlock.c:295
 __drop_extent_tree+0xdf/0x2f0 out/common/fs/f2fs/extent_cache.c:1155
 f2fs_drop_extent_tree+0x17/0x30 out/common/fs/f2fs/extent_cache.c:1172
 f2fs_insert_range out/common/fs/f2fs/file.c:1600 [inline]
 f2fs_fallocate+0x19fd/0x1f40 out/common/fs/f2fs/file.c:1764
 vfs_fallocate+0x514/0x9b0 out/common/fs/open.c:310
 ksys_fallocate out/common/fs/open.c:333 [inline]
 __do_sys_fallocate out/common/fs/open.c:341 [inline]
 __se_sys_fallocate out/common/fs/open.c:339 [inline]
 __x64_sys_fallocate+0xb8/0x100 out/common/fs/open.c:339
 do_syscall_64+0x35/0x50 out/common/arch/x86/entry/common.c:46

Cc: stable@vger.kernel.org
Fixes: 72840cccc0a1 ("f2fs: allocate the extent_cache by default")
Reported-and-tested-by: syzbot+d342e330a37b48c094b7@syzkaller.appspotmail.com
Signed-off-by: Jaegeuk Kim

f2fs: remove unnessary comment in __may_age_extent_tree

2023-04-24T18:03:10+00:00

This comment make no sense and is in the wrong place, so let's
remove it.

Signed-off-by: Qi Han 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: relax sanity check if checkpoint is corrupted

2023-04-18T16:05:54+00:00

1. extent_cache
 - let's drop the largest extent_cache
2. invalidate_block
 - don't show the warnings

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: remove entire rb_entry sharing

2023-03-29T22:17:38+00:00

This is a last part to remove the memory sharing for rb_tree in extent_cache.

This should also fix arm32 memory alignment issue.

[struct extent_node]               [struct rb_entry]
[0] struct rb_node rb_node;        [0] struct rb_node rb_node;
  union {                              union {
    struct {                             struct {
[16]  unsigned int fofs;           [12]    unsigned int ofs;
      unsigned int len;                    unsigned int len;
                                         };
                                         unsigned long long key;
                                       } __packed;

Cc: 
Fixes: 13054c548a1c ("f2fs: introduce infra macro and data structure of rb-tree extent cache")
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim