diff options
Diffstat (limited to 'fs/btrfs/send.c')
| -rw-r--r-- | fs/btrfs/send.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 516b80637bfb..383bc8a5cb6c 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1284,6 +1284,10 @@ struct backref_ctx { /* The bytenr the file extent item we are processing refers to. */ u64 bytenr; + /* The owner (root id) of the data backref for the current extent. */ + u64 backref_owner; + /* The offset of the data backref for the current extent. */ + u64 backref_offset; }; static int __clone_root_cmp_bsearch(const void *key, const void *elt) @@ -1558,6 +1562,18 @@ static int check_extent_item(u64 bytenr, const struct btrfs_extent_item *ei, return 0; } +static bool skip_self_data_ref(u64 root, u64 ino, u64 offset, void *ctx) +{ + const struct backref_ctx *bctx = ctx; + + if (ino == bctx->cur_objectid && + root == bctx->backref_owner && + offset == bctx->backref_offset) + return true; + + return false; +} + /* * Given an inode, offset and extent item, it finds a good clone for a clone * instruction. Returns -ENOENT when none could be found. The function makes @@ -1624,6 +1640,12 @@ static int find_extent_clone(struct send_ctx *sctx, backref_ctx.cur_objectid = ino; backref_ctx.cur_offset = data_offset; backref_ctx.bytenr = disk_byte; + /* + * Use the header owner and not the send root's id, because in case of a + * snapshot we can have shared subtrees. + */ + backref_ctx.backref_owner = btrfs_header_owner(eb); + backref_ctx.backref_offset = data_offset - btrfs_file_extent_offset(eb, fi); /* * The last extent of a file may be too large due to page alignment. @@ -1648,6 +1670,17 @@ static int find_extent_clone(struct send_ctx *sctx, backref_walk_ctx.check_extent_item = check_extent_item; backref_walk_ctx.user_ctx = &backref_ctx; + /* + * If have a single clone root, then it's the send root and we can tell + * the backref walking code to skip our own backref and not resolve it, + * since we can not use it for cloning - the source and destination + * ranges can't overlap and in case the leaf is shared through a subtree + * due to snapshots, we can't use those other roots since they are not + * in the list of clone roots. + */ + if (sctx->clone_roots_cnt == 1) + backref_walk_ctx.skip_data_ref = skip_self_data_ref; + ret = iterate_extent_inodes(&backref_walk_ctx, true, iterate_backrefs, &backref_ctx); if (ret < 0) |