f2fs: fix to handle segment allocation failure correctly

If CONFIG_F2FS_CHECK_FS is off, and for very rare corner case that
we run out of free segment, we should not panic kernel, instead,
let's handle such error correctly in its caller.

Signed-off-by: Chao Yu <chao@kernel.org>
Tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 39 insertions, 7 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index dc511630eaa5..a5339dd7a932 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -400,6 +400,9 @@ int f2fs_commit_atomic_write(struct inode *inode)
  */
 void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
 {
+	if (f2fs_cp_error(sbi))
+		return;
+
 	if (time_to_inject(sbi, FAULT_CHECKPOINT))
 		f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_FAULT_INJECT);
 
@@ -2639,7 +2642,7 @@ static int is_next_segment_free(struct f2fs_sb_info *sbi,
  * Find a new segment from the free segments bitmap to right order
  * This function should be returned with success, otherwise BUG
  */
-static void get_new_segment(struct f2fs_sb_info *sbi,
+static int get_new_segment(struct f2fs_sb_info *sbi,
 			unsigned int *newseg, bool new_sec, bool pinning)
 {
 	struct free_segmap_info *free_i = FREE_I(sbi);
@@ -2714,6 +2717,7 @@ out_unlock:
 		f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
 		f2fs_bug_on(sbi, 1);
 	}
+	return ret;
 }
 
 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
@@ -2722,6 +2726,10 @@ static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
 	struct summary_footer *sum_footer;
 	unsigned short seg_type = curseg->seg_type;
 
+	/* only happen when get_new_segment() fails */
+	if (curseg->next_segno == NULL_SEGNO)
+		return;
+
 	curseg->inited = true;
 	curseg->segno = curseg->next_segno;
 	curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
@@ -2786,7 +2794,10 @@ static int new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
 		write_sum_page(sbi, curseg->sum_blk, GET_SUM_BLOCK(sbi, segno));
 
 	segno = __get_next_segno(sbi, type);
-	get_new_segment(sbi, &segno, new_sec, pinning);
+	if (get_new_segment(sbi, &segno, new_sec, pinning)) {
+		curseg->segno = NULL_SEGNO;
+		return -ENOSPC;
+	}
 	if (new_sec && pinning &&
 	    !f2fs_valid_pinned_area(sbi, START_BLOCK(sbi, segno))) {
 		__set_free(sbi, segno);
@@ -3428,7 +3439,7 @@ static void f2fs_randomize_chunk(struct f2fs_sb_info *sbi,
 		get_random_u32_inclusive(1, sbi->max_fragment_hole);
 }
 
-void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
+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,
 		struct f2fs_io_info *fio)
@@ -3445,6 +3456,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 	mutex_lock(&curseg->curseg_mutex);
 	down_write(&sit_i->sentry_lock);
 
+	if (curseg->segno == NULL_SEGNO)
+		goto out_err;
+
 	if (from_gc) {
 		f2fs_bug_on(sbi, GET_SEGNO(sbi, old_blkaddr) == NULL_SEGNO);
 		se = get_seg_entry(sbi, GET_SEGNO(sbi, old_blkaddr));
@@ -3504,6 +3518,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 				change_curseg(sbi, type);
 			stat_inc_seg_type(sbi, curseg);
 		}
+
+		if (curseg->segno == NULL_SEGNO)
+			goto out_err;
 	}
 
 skip_new_segment:
@@ -3538,8 +3555,15 @@ skip_new_segment:
 	}
 
 	mutex_unlock(&curseg->curseg_mutex);
-
 	f2fs_up_read(&SM_I(sbi)->curseg_lock);
+	return 0;
+out_err:
+	*new_blkaddr = NULL_ADDR;
+	up_write(&sit_i->sentry_lock);
+	mutex_unlock(&curseg->curseg_mutex);
+	f2fs_up_read(&SM_I(sbi)->curseg_lock);
+	return -ENOSPC;
+
 }
 
 void f2fs_update_device_state(struct f2fs_sb_info *sbi, nid_t ino,
@@ -3577,8 +3601,16 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 	if (keep_order)
 		f2fs_down_read(&fio->sbi->io_order_lock);
 
-	f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
-			&fio->new_blkaddr, sum, type, fio);
+	if (f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
+			&fio->new_blkaddr, sum, type, fio)) {
+		if (fscrypt_inode_uses_fs_layer_crypto(fio->page->mapping->host))
+			fscrypt_finalize_bounce_page(&fio->encrypted_page);
+		if (PageWriteback(fio->page))
+			end_page_writeback(fio->page);
+		if (f2fs_in_warm_node_list(fio->sbi, fio->page))
+			f2fs_del_fsync_node_entry(fio->sbi, fio->page);
+		goto out;
+	}
 	if (GET_SEGNO(fio->sbi, fio->old_blkaddr) != NULL_SEGNO)
 		f2fs_invalidate_internal_cache(fio->sbi, fio->old_blkaddr);
 
@@ -3586,7 +3618,7 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
 	f2fs_submit_page_write(fio);
 
 	f2fs_update_device_state(fio->sbi, fio->ino, fio->new_blkaddr, 1);
-
+out:
 	if (keep_order)
 		f2fs_up_read(&fio->sbi->io_order_lock);
 }