提交 1f4692da 编写于 作者: A Alexander Block 提交者: Chris Mason

Btrfs: fix cur_ino < parent_ino case for send/receive

When the current inodes inum is smaller then the inum of the
parent directory strange things were happending due to wrong
path resolution and other bugs. Fix this with a new approach
for the problem.
Reported-by: NAlex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: NAlexander Block <ablock84@googlemail.com>
上级 85a7b33b
......@@ -107,7 +107,6 @@ struct send_ctx {
int cur_inode_new;
int cur_inode_new_gen;
int cur_inode_deleted;
int cur_inode_first_ref_orphan;
u64 cur_inode_size;
u64 cur_inode_mode;
......@@ -2296,25 +2295,25 @@ verbose_printk("btrfs: send_utimes %llu\n", ino);
* a valid path yet because we did not process the refs yet. So, the inode
* is created as orphan.
*/
static int send_create_inode(struct send_ctx *sctx, struct btrfs_path *path,
struct btrfs_key *key)
static int send_create_inode(struct send_ctx *sctx, u64 ino)
{
int ret = 0;
struct extent_buffer *eb = path->nodes[0];
struct btrfs_inode_item *ii;
struct fs_path *p;
int slot = path->slots[0];
int cmd;
u64 gen;
u64 mode;
u64 rdev;
verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino);
verbose_printk("btrfs: send_create_inode %llu\n", ino);
p = fs_path_alloc(sctx);
if (!p)
return -ENOMEM;
ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
mode = btrfs_inode_mode(eb, ii);
ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode, NULL,
NULL, &rdev);
if (ret < 0)
goto out;
if (S_ISREG(mode))
cmd = BTRFS_SEND_C_MKFILE;
......@@ -2339,22 +2338,22 @@ verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino);
if (ret < 0)
goto out;
ret = gen_unique_name(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
ret = gen_unique_name(sctx, ino, gen, p);
if (ret < 0)
goto out;
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, sctx->cur_ino);
TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
if (S_ISLNK(mode)) {
fs_path_reset(p);
ret = read_symlink(sctx, sctx->send_root, sctx->cur_ino, p);
ret = read_symlink(sctx, sctx->send_root, ino, p);
if (ret < 0)
goto out;
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
} else if (S_ISCHR(mode) || S_ISBLK(mode) ||
S_ISFIFO(mode) || S_ISSOCK(mode)) {
TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, btrfs_inode_rdev(eb, ii));
TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, rdev);
}
ret = send_cmd(sctx);
......@@ -2368,6 +2367,92 @@ verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino);
return ret;
}
/*
* We need some special handling for inodes that get processed before the parent
* directory got created. See process_recorded_refs for details.
* This function does the check if we already created the dir out of order.
*/
static int did_create_dir(struct send_ctx *sctx, u64 dir)
{
int ret = 0;
struct btrfs_path *path = NULL;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_key di_key;
struct extent_buffer *eb;
struct btrfs_dir_item *di;
int slot;
path = alloc_path_for_send();
if (!path) {
ret = -ENOMEM;
goto out;
}
key.objectid = dir;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = 0;
while (1) {
ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
1, 0);
if (ret < 0)
goto out;
if (!ret) {
eb = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(eb, &found_key, slot);
}
if (ret || found_key.objectid != key.objectid ||
found_key.type != key.type) {
ret = 0;
goto out;
}
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
if (di_key.objectid < sctx->send_progress) {
ret = 1;
goto out;
}
key.offset = found_key.offset + 1;
btrfs_release_path(path);
}
out:
btrfs_free_path(path);
return ret;
}
/*
* Only creates the inode if it is:
* 1. Not a directory
* 2. Or a directory which was not created already due to out of order
* directories. See did_create_dir and process_recorded_refs for details.
*/
static int send_create_inode_if_needed(struct send_ctx *sctx)
{
int ret;
if (S_ISDIR(sctx->cur_inode_mode)) {
ret = did_create_dir(sctx, sctx->cur_ino);
if (ret < 0)
goto out;
if (ret) {
ret = 0;
goto out;
}
}
ret = send_create_inode(sctx, sctx->cur_ino);
if (ret < 0)
goto out;
out:
return ret;
}
struct recorded_ref {
struct list_head list;
char *dir_path;
......@@ -2517,160 +2602,6 @@ static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress)
return ret;
}
struct finish_unordered_dir_ctx {
struct send_ctx *sctx;
struct fs_path *cur_path;
struct fs_path *dir_path;
u64 dir_ino;
int need_delete;
int delete_pass;
};
int __finish_unordered_dir(int num, struct btrfs_key *di_key,
const char *name, int name_len,
const char *data, int data_len,
u8 type, void *ctx)
{
int ret = 0;
struct finish_unordered_dir_ctx *fctx = ctx;
struct send_ctx *sctx = fctx->sctx;
u64 di_gen;
u64 di_mode;
int is_orphan = 0;
if (di_key->objectid >= fctx->dir_ino)
goto out;
fs_path_reset(fctx->cur_path);
ret = get_inode_info(sctx->send_root, di_key->objectid,
NULL, &di_gen, &di_mode, NULL, NULL, NULL);
if (ret < 0)
goto out;
ret = is_first_ref(sctx, sctx->send_root, di_key->objectid,
fctx->dir_ino, name, name_len);
if (ret < 0)
goto out;
if (ret) {
is_orphan = 1;
ret = gen_unique_name(sctx, di_key->objectid, di_gen,
fctx->cur_path);
} else {
ret = get_cur_path(sctx, di_key->objectid, di_gen,
fctx->cur_path);
}
if (ret < 0)
goto out;
ret = fs_path_add(fctx->dir_path, name, name_len);
if (ret < 0)
goto out;
if (!fctx->delete_pass) {
if (S_ISDIR(di_mode)) {
ret = send_rename(sctx, fctx->cur_path,
fctx->dir_path);
} else {
ret = send_link(sctx, fctx->dir_path,
fctx->cur_path);
if (is_orphan)
fctx->need_delete = 1;
}
} else if (!S_ISDIR(di_mode)) {
ret = send_unlink(sctx, fctx->cur_path);
} else {
ret = 0;
}
fs_path_remove(fctx->dir_path);
out:
return ret;
}
/*
* Go through all dir items and see if we find refs which could not be created
* in the past because the dir did not exist at that time.
*/
static int finish_outoforder_dir(struct send_ctx *sctx, u64 dir, u64 dir_gen)
{
int ret = 0;
struct btrfs_path *path = NULL;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *eb;
struct finish_unordered_dir_ctx fctx;
int slot;
path = alloc_path_for_send();
if (!path) {
ret = -ENOMEM;
goto out;
}
memset(&fctx, 0, sizeof(fctx));
fctx.sctx = sctx;
fctx.cur_path = fs_path_alloc(sctx);
fctx.dir_path = fs_path_alloc(sctx);
if (!fctx.cur_path || !fctx.dir_path) {
ret = -ENOMEM;
goto out;
}
fctx.dir_ino = dir;
ret = get_cur_path(sctx, dir, dir_gen, fctx.dir_path);
if (ret < 0)
goto out;
/*
* We do two passes. The first links in the new refs and the second
* deletes orphans if required. Deletion of orphans is not required for
* directory inodes, as we always have only one ref and use rename
* instead of link for those.
*/
again:
key.objectid = dir;
key.type = BTRFS_DIR_ITEM_KEY;
key.offset = 0;
while (1) {
ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
1, 0);
if (ret < 0)
goto out;
eb = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(eb, &found_key, slot);
if (found_key.objectid != key.objectid ||
found_key.type != key.type) {
btrfs_release_path(path);
break;
}
ret = iterate_dir_item(sctx, sctx->send_root, path,
&found_key, __finish_unordered_dir,
&fctx);
if (ret < 0)
goto out;
key.offset = found_key.offset + 1;
btrfs_release_path(path);
}
if (!fctx.delete_pass && fctx.need_delete) {
fctx.delete_pass = 1;
goto again;
}
out:
btrfs_free_path(path);
fs_path_free(sctx, fctx.cur_path);
fs_path_free(sctx, fctx.dir_path);
return ret;
}
/*
* This does all the move/link/unlink/rmdir magic.
*/
......@@ -2678,6 +2609,7 @@ static int process_recorded_refs(struct send_ctx *sctx)
{
int ret = 0;
struct recorded_ref *cur;
struct recorded_ref *cur2;
struct ulist *check_dirs = NULL;
struct ulist_iterator uit;
struct ulist_node *un;
......@@ -2734,6 +2666,46 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
}
list_for_each_entry(cur, &sctx->new_refs, list) {
/*
* We may have refs where the parent directory does not exist
* yet. This happens if the parent directories inum is higher
* the the current inum. To handle this case, we create the
* parent directory out of order. But we need to check if this
* did already happen before due to other refs in the same dir.
*/
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
if (ret < 0)
goto out;
if (ret == inode_state_will_create) {
ret = 0;
/*
* First check if any of the current inodes refs did
* already create the dir.
*/
list_for_each_entry(cur2, &sctx->new_refs, list) {
if (cur == cur2)
break;
if (cur2->dir == cur->dir) {
ret = 1;
break;
}
}
/*
* If that did not happen, check if a previous inode
* did already create the dir.
*/
if (!ret)
ret = did_create_dir(sctx, cur->dir);
if (ret < 0)
goto out;
if (!ret) {
ret = send_create_inode(sctx, cur->dir);
if (ret < 0)
goto out;
}
}
/*
* Check if this new ref would overwrite the first ref of
* another unprocessed inode. If yes, orphanize the
......@@ -2768,7 +2740,7 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
* inode, move it and update valid_path. If not, link or move
* it depending on the inode mode.
*/
if (is_orphan && !sctx->cur_inode_first_ref_orphan) {
if (is_orphan) {
ret = send_rename(sctx, valid_path, cur->full_path);
if (ret < 0)
goto out;
......@@ -2844,35 +2816,9 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
if (ret < 0)
goto out;
if (!ret) {
/*
* In case the inode was moved to a directory
* that was not created yet (see
* __record_new_ref), we can not unlink the ref
* as it will be needed later when the parent
* directory is created, so that we can move in
* the inode to the new dir.
*/
if (!is_orphan &&
sctx->cur_inode_first_ref_orphan) {
ret = orphanize_inode(sctx,
sctx->cur_ino,
sctx->cur_inode_gen,
cur->full_path);
if (ret < 0)
goto out;
ret = gen_unique_name(sctx,
sctx->cur_ino,
sctx->cur_inode_gen,
valid_path);
if (ret < 0)
goto out;
is_orphan = 1;
} else {
ret = send_unlink(sctx, cur->full_path);
if (ret < 0)
goto out;
}
ret = send_unlink(sctx, cur->full_path);
if (ret < 0)
goto out;
}
ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
GFP_NOFS);
......@@ -2885,11 +2831,8 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
* happen when a previous inode did overwrite the first ref
* of this inode and no new refs were added for the current
* inode.
* We can however not delete the orphan in case the inode relies
* in a directory that was not created yet (see
* __record_new_ref)
*/
if (is_orphan && !sctx->cur_inode_first_ref_orphan) {
if (is_orphan) {
ret = send_unlink(sctx, valid_path);
if (ret < 0)
goto out;
......@@ -2939,19 +2882,6 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
*/
sctx->send_progress = sctx->cur_ino + 1;
/*
* We may have a directory here that has pending refs which could not
* be created before (because the dir did not exist before, see
* __record_new_ref). finish_outoforder_dir will link/move the pending
* refs.
*/
if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_new) {
ret = finish_outoforder_dir(sctx, sctx->cur_ino,
sctx->cur_inode_gen);
if (ret < 0)
goto out;
}
ret = 0;
out:
......@@ -2979,31 +2909,6 @@ static int __record_new_ref(int num, u64 dir, int index,
if (ret < 0)
goto out;
/*
* The parent may be non-existent at this point in time. This happens
* if the ino of the parent dir is higher then the current ino. In this
* case, we can not process this ref until the parent dir is finally
* created. If we reach the parent dir later, process_recorded_refs
* will go through all dir items and process the refs that could not be
* processed before. In case this is the first ref, we set
* cur_inode_first_ref_orphan to 1 to inform process_recorded_refs to
* keep an orphan of the inode so that it later can be used for
* link/move
*/
ret = is_inode_existent(sctx, dir, gen);
if (ret < 0)
goto out;
if (!ret) {
ret = is_first_ref(sctx, sctx->send_root, sctx->cur_ino, dir,
name->start, fs_path_len(name));
if (ret < 0)
goto out;
if (ret)
sctx->cur_inode_first_ref_orphan = 1;
ret = 0;
goto out;
}
ret = get_cur_path(sctx, dir, gen, p);
if (ret < 0)
goto out;
......@@ -4078,7 +3983,6 @@ static int changed_inode(struct send_ctx *sctx,
sctx->cur_ino = key->objectid;
sctx->cur_inode_new_gen = 0;
sctx->cur_inode_first_ref_orphan = 0;
sctx->send_progress = sctx->cur_ino;
if (result == BTRFS_COMPARE_TREE_NEW ||
......@@ -4115,8 +4019,7 @@ static int changed_inode(struct send_ctx *sctx,
sctx->cur_inode_mode = btrfs_inode_mode(
sctx->left_path->nodes[0], left_ii);
if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
ret = send_create_inode(sctx, sctx->left_path,
sctx->cmp_key);
ret = send_create_inode_if_needed(sctx);
} else if (result == BTRFS_COMPARE_TREE_DELETED) {
sctx->cur_inode_gen = right_gen;
sctx->cur_inode_new = 0;
......@@ -4146,8 +4049,7 @@ static int changed_inode(struct send_ctx *sctx,
sctx->left_path->nodes[0], left_ii);
sctx->cur_inode_mode = btrfs_inode_mode(
sctx->left_path->nodes[0], left_ii);
ret = send_create_inode(sctx, sctx->left_path,
sctx->cmp_key);
ret = send_create_inode_if_needed(sctx);
if (ret < 0)
goto out;
......
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