From: Chao Yu chao@kernel.org
[ Upstream commit 48ea8b200414ac69ea96f4c231f5c7ef1fbeffef ]
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+15669ec8c35ddf6c3d43@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/675cd64e.050a0220.37aaf.00bb.GAE@go... Signed-off-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Rajani Kantha 681739313@139.com --- 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 2a108c561e8b..6317dd523ecd 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1836,18 +1836,20 @@ 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 e48b5e2efea2..8ac6206110a1 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -2749,7 +2749,7 @@ 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; } } @@ -2795,7 +2795,7 @@ 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; } @@ -2868,6 +2868,13 @@ 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. @@ -2886,7 +2893,7 @@ 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; }
@@ -3640,13 +3647,6 @@ 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,