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-rw-r--r--fs/nilfs2/segment.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 1491a4d4b1e1..9332f5ac6083 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2512,12 +2512,33 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
struct nilfs_sc_info *sci = nilfs->ns_writer;
struct nilfs_transaction_info ti;
int err;
+ size_t i, nfreesegs = argv[4].v_nmembs;
+ __u64 *segnumv = kbufs[4];
if (unlikely(!sci))
return -EROFS;
nilfs_transaction_lock(sb, &ti, 1);
+ /*
+ * Validate segment numbers under ns_segctor_sem (held for write
+ * by nilfs_transaction_lock above) so the check is serialized
+ * against nilfs_ioctl_resize(), which can modify ns_nsegments.
+ * Rejecting bad input here, before any segment-cleaning work
+ * begins, avoids the per-element diagnostic path inside
+ * nilfs_sufile_updatev() that would otherwise run under this
+ * same lock and stall concurrent readers.
+ */
+ for (i = 0; i < nfreesegs; i++) {
+ if (segnumv[i] >= nilfs->ns_nsegments) {
+ nilfs_err(sb,
+ "Segment number %llu to be freed is out of range",
+ (unsigned long long)segnumv[i]);
+ err = -EINVAL;
+ goto bail_unlock;
+ }
+ }
+
err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
if (unlikely(err))
goto out_unlock;
@@ -2558,6 +2579,7 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
sci->sc_freesegs = NULL;
sci->sc_nfreesegs = 0;
nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
+ bail_unlock:
nilfs_transaction_unlock(sb);
return err;
}