From 69917e431210f8712fe050f47b7561e7dae89521 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 7 Sep 2012 20:01:28 -0600 Subject: [PATCH] Btrfs: fix a bug in parsing return value in logical resolve In logical resolve, we parse extent_from_logical()'s 'ret' as a kind of flag. It is possible to lose our errors because (-EXXXX & BTRFS_EXTENT_FLAG_TREE_BLOCK) is true. I'm not sure if it is on purpose, it just looks too hacky if it is. I'd rather use a real flag and a 'ret' to catch errors. Acked-by: Jan Schmidt Signed-off-by: Liu Bo --- fs/btrfs/backref.c | 24 ++++++++++++++++-------- fs/btrfs/backref.h | 3 ++- fs/btrfs/ioctl.c | 6 ++++-- fs/btrfs/scrub.c | 16 +++++++++------- fs/btrfs/send.c | 7 ++++--- 5 files changed, 35 insertions(+), 21 deletions(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index e600857d3ca4..ab286e5bfe33 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -1193,7 +1193,8 @@ char *btrfs_iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, * tree blocks and <0 on error. */ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, - struct btrfs_path *path, struct btrfs_key *found_key) + struct btrfs_path *path, struct btrfs_key *found_key, + u64 *flags_ret) { int ret; u64 flags; @@ -1237,10 +1238,17 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, (unsigned long long)found_key->objectid, (unsigned long long)found_key->offset, (unsigned long long)flags, item_size); - if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) - return BTRFS_EXTENT_FLAG_TREE_BLOCK; - if (flags & BTRFS_EXTENT_FLAG_DATA) - return BTRFS_EXTENT_FLAG_DATA; + + WARN_ON(!flags_ret); + if (flags_ret) { + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) + *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK; + else if (flags & BTRFS_EXTENT_FLAG_DATA) + *flags_ret = BTRFS_EXTENT_FLAG_DATA; + else + BUG_ON(1); + return 0; + } return -EIO; } @@ -1433,15 +1441,15 @@ int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, { int ret; u64 extent_item_pos; + u64 flags = 0; struct btrfs_key found_key; int search_commit_root = path->search_commit_root; - ret = extent_from_logical(fs_info, logical, path, - &found_key); + ret = extent_from_logical(fs_info, logical, path, &found_key, &flags); btrfs_release_path(path); if (ret < 0) return ret; - if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) return -EINVAL; extent_item_pos = logical - found_key.objectid; diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 032f4dc7eab8..4fda5d8029a7 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -40,7 +40,8 @@ int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, struct btrfs_path *path); int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, - struct btrfs_path *path, struct btrfs_key *found_key); + struct btrfs_path *path, struct btrfs_key *found_key, + u64 *flags); int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, struct btrfs_extent_item *ei, u32 item_size, diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index de886ac7ba0f..48ff3f7317b0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3211,6 +3211,7 @@ static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root, int ret = 0; int size; u64 extent_item_pos; + u64 flags = 0; struct btrfs_ioctl_logical_ino_args *loi; struct btrfs_data_container *inodes = NULL; struct btrfs_path *path = NULL; @@ -3240,10 +3241,11 @@ static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root, goto out; } - ret = extent_from_logical(root->fs_info, loi->logical, path, &key); + ret = extent_from_logical(root->fs_info, loi->logical, path, &key, + &flags); btrfs_release_path(path); - if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) ret = -ENOENT; if (ret < 0) goto out; diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 4e9eafe01c55..d3bb901ade42 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -352,13 +352,14 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) struct extent_buffer *eb; struct btrfs_extent_item *ei; struct scrub_warning swarn; - u32 item_size; - int ret; - u64 ref_root; - u8 ref_level; unsigned long ptr = 0; - const int bufsize = 4096; u64 extent_item_pos; + u64 flags = 0; + u64 ref_root; + u32 item_size; + u8 ref_level; + const int bufsize = 4096; + int ret; path = btrfs_alloc_path(); @@ -375,7 +376,8 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) if (!path || !swarn.scratch_buf || !swarn.msg_buf) goto out; - ret = extent_from_logical(fs_info, swarn.logical, path, &found_key); + ret = extent_from_logical(fs_info, swarn.logical, path, &found_key, + &flags); if (ret < 0) goto out; @@ -387,7 +389,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock) item_size = btrfs_item_size_nr(eb, path->slots[0]); btrfs_release_path(path); - if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { do { ret = tree_backref_for_extent(&ptr, eb, ei, item_size, &ref_root, &ref_level); diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index e5c867996aa0..c6ef070a8dca 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1152,6 +1152,7 @@ static int find_extent_clone(struct send_ctx *sctx, u64 disk_byte; u64 num_bytes; u64 extent_item_pos; + u64 flags = 0; struct btrfs_file_extent_item *fi; struct extent_buffer *eb = path->nodes[0]; struct backref_ctx *backref_ctx = NULL; @@ -1198,13 +1199,13 @@ static int find_extent_clone(struct send_ctx *sctx, } logical = disk_byte + btrfs_file_extent_offset(eb, fi); - ret = extent_from_logical(sctx->send_root->fs_info, - disk_byte, tmp_path, &found_key); + ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path, + &found_key, &flags); btrfs_release_path(tmp_path); if (ret < 0) goto out; - if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { ret = -EIO; goto out; }