syzbot reports a f2fs bug as below:
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2746!
CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted
6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0
RIP: 0010:get_new_segment fs/f2fs/segment.c:2746 [inline]
RIP: 0010:new_curseg+0x1f52/0x1f70 fs/f2fs/segment.c:2876
Call Trace:
<TASK>
__allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3210
f2fs_allocate_new_section fs/f2fs/segment.c:3224 [inline]
f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3238
f2fs_expand_inode_data+0x696/0xca0 fs/f2fs/file.c:1830
f2fs_fallocate+0x537/0xa10 fs/f2fs/file.c:1940
vfs_fallocate+0x569/0x6e0 fs/open.c:327
do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x80/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Concurrent pinfile allocation may run out of free section, result in
panic in get_new_segment(), let's expand pin_sem lock coverage to
include f2fs_gc(), so that we can make sure to reclaim enough free
space for following allocation.
In addition, do below changes to enhance error path handling:
- call f2fs_bug_on() only in non-pinfile allocation path in
get_new_segment().
- call reset_curseg_fields() to reset all fields of curseg in
new_curseg()
Fixes: f5a53edcf01e ("f2fs: support aligned pinned file")
Reported-by: syzbot+15669ec8c35ddf6c3...@syzkaller.appspotmail.com
Closes:
https://lore.kernel.org/linux-f2fs-devel/675cd64e.050a0220.37aaf.00bb....@google.com
Signed-off-by: Chao Yu <c...@kernel.org>
---
fs/f2fs/file.c | 8 +++++---
fs/f2fs/segment.c | 20 ++++++++++----------
2 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 2f93a27d2f45..4c563edbf5c6 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1834,18 +1834,20 @@ static int f2fs_expand_inode_data(struct inode *inode,
loff_t offset,
map.m_len = sec_blks;
next_alloc:
+ f2fs_down_write(&sbi->pin_sem);
+
if (has_not_enough_free_secs(sbi, 0, f2fs_sb_has_blkzoned(sbi) ?
ZONED_PIN_SEC_REQUIRED_COUNT :
GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
f2fs_down_write(&sbi->gc_lock);
stat_inc_gc_call_count(sbi, FOREGROUND);
err = f2fs_gc(sbi, &gc_control);
- if (err && err != -ENODATA)
+ if (err && err != -ENODATA) {
+ f2fs_up_write(&sbi->pin_sem);
goto out_err;
+ }
}
- f2fs_down_write(&sbi->pin_sem);
-
err = f2fs_allocate_pinning_section(sbi);
if (err) {
f2fs_up_write(&sbi->pin_sem);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c282e8a0a2ec..6ebe25eafafa 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2806,7 +2806,7 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
MAIN_SECS(sbi));
if (secno >= MAIN_SECS(sbi)) {
ret = -ENOSPC;
- f2fs_bug_on(sbi, 1);
+ f2fs_bug_on(sbi, !pinning);
goto out_unlock;
}
}
@@ -2848,7 +2848,7 @@ static int get_new_segment(struct f2fs_sb_info *sbi,
out_unlock:
spin_unlock(&free_i->segmap_lock);
- if (ret == -ENOSPC)
+ if (ret == -ENOSPC && !pinning)
f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
return ret;
}
@@ -2921,6 +2921,13 @@ static unsigned int __get_next_segno(struct f2fs_sb_info
*sbi, int type)
return curseg->segno;
}
+static void reset_curseg_fields(struct curseg_info *curseg)
+{
+ curseg->inited = false;
+ curseg->segno = NULL_SEGNO;
+ curseg->next_segno = 0;
+}
+
/*
* Allocate a current working segment.
* This function always allocates a free segment in LFS manner.
@@ -2939,7 +2946,7 @@ static int new_curseg(struct f2fs_sb_info *sbi, int type,
bool new_sec)
ret = get_new_segment(sbi, &segno, new_sec, pinning);
if (ret) {
if (ret == -ENOSPC)
- curseg->segno = NULL_SEGNO;
+ reset_curseg_fields(curseg);
return ret;
}
@@ -3710,13 +3717,6 @@ static void f2fs_randomize_chunk(struct f2fs_sb_info
*sbi,
get_random_u32_inclusive(1, sbi->max_fragment_hole);
}
-static void reset_curseg_fields(struct curseg_info *curseg)
-{
- curseg->inited = false;
- curseg->segno = NULL_SEGNO;
- curseg->next_segno = 0;
-}
-
int f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
block_t old_blkaddr, block_t *new_blkaddr,
struct f2fs_summary *sum, int type,
--
2.48.1.502.g6dc24dfdaf-goog
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