[PATCH 4/6] Btrfs: fix a bug in parsing return value in logical resolve
From: Liu Bo <hidden>
Date: 2012-08-31 05:38:43
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
From: Liu Bo <redacted> 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 <redacted> Signed-off-by: Liu Bo <redacted> --- fs/btrfs/backref.c | 24 ++++++++++++++++-------- fs/btrfs/backref.h | 3 ++- fs/btrfs/ioctl.c | 6 ++++-- fs/btrfs/scrub.c | 14 ++++++++------ fs/btrfs/send.c | 7 ++++--- 5 files changed, 34 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index ff6475f..4e80ba3 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; }
@@ -1432,15 +1440,15 @@ 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 032f4dc..4fda5d8 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 7390b25..123ffee 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c@@ -3217,6 +3217,7 @@ 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;
@@ -3246,10 +3247,11 @@ 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 b223620..5def223 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; + unsigned long ptr = 0; + u64 extent_item_pos; + u64 flags = 0; u64 ref_root; + u32 item_size; u8 ref_level; - unsigned long ptr = 0; const int bufsize = 4096; - u64 extent_item_pos; + 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 fb5ffe9..7186ae8 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c@@ -1143,6 +1143,7 @@ static int find_extent_clone(struct send_ctx *sctx, u64 logical; 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;
@@ -1181,13 +1182,13 @@ static int find_extent_clone(struct send_ctx *sctx, } logical += btrfs_file_extent_offset(eb, fi); - ret = extent_from_logical(sctx->send_root->fs_info, - logical, tmp_path, &found_key); + ret = extent_from_logical(sctx->send_root->fs_info, logical, 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; }
--
1.7.7.6