summaryrefslogtreecommitdiff
path: root/fs/btrfs/inode.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/btrfs/inode.c')
-rw-r--r--fs/btrfs/inode.c52
1 files changed, 37 insertions, 15 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6d1b93c8aafb..021694c08181 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2166,16 +2166,23 @@ static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
continue;
- extent_offset = btrfs_file_extent_offset(leaf, extent);
- if (key.offset - extent_offset != offset)
+ /*
+ * 'offset' refers to the exact key.offset,
+ * NOT the 'offset' field in btrfs_extent_data_ref, ie.
+ * (key.offset - extent_offset).
+ */
+ if (key.offset != offset)
continue;
+ extent_offset = btrfs_file_extent_offset(leaf, extent);
num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
+
if (extent_offset >= old->extent_offset + old->offset +
old->len || extent_offset + num_bytes <=
old->extent_offset + old->offset)
continue;
+ ret = 0;
break;
}
@@ -2187,7 +2194,7 @@ static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
backref->root_id = root_id;
backref->inum = inum;
- backref->file_pos = offset + extent_offset;
+ backref->file_pos = offset;
backref->num_bytes = num_bytes;
backref->extent_offset = extent_offset;
backref->generation = btrfs_file_extent_generation(leaf, extent);
@@ -2210,7 +2217,8 @@ static noinline bool record_extent_backrefs(struct btrfs_path *path,
new->path = path;
list_for_each_entry_safe(old, tmp, &new->head, list) {
- ret = iterate_inodes_from_logical(old->bytenr, fs_info,
+ ret = iterate_inodes_from_logical(old->bytenr +
+ old->extent_offset, fs_info,
path, record_one_backref,
old);
BUG_ON(ret < 0 && ret != -ENOENT);
@@ -4391,9 +4399,6 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
int mask = attr->ia_valid;
int ret;
- if (newsize == oldsize)
- return 0;
-
/*
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
* special case where we need to update the times despite not having
@@ -5165,14 +5170,31 @@ next:
}
/* Reached end of directory/root. Bump pos past the last item. */
- if (key_type == BTRFS_DIR_INDEX_KEY)
- /*
- * 32-bit glibc will use getdents64, but then strtol -
- * so the last number we can serve is this.
- */
- ctx->pos = 0x7fffffff;
- else
- ctx->pos++;
+ ctx->pos++;
+
+ /*
+ * Stop new entries from being returned after we return the last
+ * entry.
+ *
+ * New directory entries are assigned a strictly increasing
+ * offset. This means that new entries created during readdir
+ * are *guaranteed* to be seen in the future by that readdir.
+ * This has broken buggy programs which operate on names as
+ * they're returned by readdir. Until we re-use freed offsets
+ * we have this hack to stop new entries from being returned
+ * under the assumption that they'll never reach this huge
+ * offset.
+ *
+ * This is being careful not to overflow 32bit loff_t unless the
+ * last entry requires it because doing so has broken 32bit apps
+ * in the past.
+ */
+ if (key_type == BTRFS_DIR_INDEX_KEY) {
+ if (ctx->pos >= INT_MAX)
+ ctx->pos = LLONG_MAX;
+ else
+ ctx->pos = INT_MAX;
+ }
nopos:
ret = 0;
err: