f2fs: stop checkpoint when get a out-of-bounds segment

There is low probability that an out-of-bounds segment will be got
on a small-capacity device. In order to prevent subsequent write requests
allocating block address from this invalid segment, which may cause
unexpected issue, stop checkpoint should be performed.

Also introduce a new stop cp reason: STOP_CP_REASON_NO_SEGMENT.

Note, f2fs_stop_checkpoint(, false) is complex and it may sleep, so we should
move it outside segmap_lock spinlock coverage in get_new_segment().

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

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 0106725..dc51163 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2649,6 +2649,7 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
        unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
        bool init = true;
        int i;
+       int ret = 0;
 
        spin_lock(&free_i->segmap_lock);
 
@@ -2673,7 +2674,10 @@ find_other_zone:
        if (secno >= MAIN_SECS(sbi)) {
                secno = find_first_zero_bit(free_i->free_secmap,
                                                        MAIN_SECS(sbi));
-               f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
+               if (secno >= MAIN_SECS(sbi)) {
+                       ret = -ENOSPC;
+                       goto out_unlock;
+               }
        }
        segno = GET_SEG_FROM_SEC(sbi, secno);
        zoneno = GET_ZONE_FROM_SEC(sbi, secno);
@@ -2703,7 +2707,13 @@ got_it:
        f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
        __set_inuse(sbi, segno);
        *newseg = segno;
+out_unlock:
        spin_unlock(&free_i->segmap_lock);
+
+       if (ret) {
+               f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_NO_SEGMENT);
+               f2fs_bug_on(sbi, 1);
+       }
 }
 
 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)

diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 9b69c50..755e9a4 100644 (file)
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -75,6 +75,7 @@ enum stop_cp_reason {
        STOP_CP_REASON_CORRUPTED_SUMMARY,
        STOP_CP_REASON_UPDATE_INODE,
        STOP_CP_REASON_FLUSH_FAIL,
+       STOP_CP_REASON_NO_SEGMENT,
        STOP_CP_REASON_MAX,
 };