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-rw-r--r--fs/btrfs/send.c539
1 files changed, 518 insertions, 21 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index fc1f0abb8fe4..c96e879bcb16 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -121,6 +121,74 @@ struct send_ctx {
int name_cache_size;
char *read_buf;
+
+ /*
+ * We process inodes by their increasing order, so if before an
+ * incremental send we reverse the parent/child relationship of
+ * directories such that a directory with a lower inode number was
+ * the parent of a directory with a higher inode number, and the one
+ * becoming the new parent got renamed too, we can't rename/move the
+ * directory with lower inode number when we finish processing it - we
+ * must process the directory with higher inode number first, then
+ * rename/move it and then rename/move the directory with lower inode
+ * number. Example follows.
+ *
+ * Tree state when the first send was performed:
+ *
+ * .
+ * |-- a (ino 257)
+ * |-- b (ino 258)
+ * |
+ * |
+ * |-- c (ino 259)
+ * | |-- d (ino 260)
+ * |
+ * |-- c2 (ino 261)
+ *
+ * Tree state when the second (incremental) send is performed:
+ *
+ * .
+ * |-- a (ino 257)
+ * |-- b (ino 258)
+ * |-- c2 (ino 261)
+ * |-- d2 (ino 260)
+ * |-- cc (ino 259)
+ *
+ * The sequence of steps that lead to the second state was:
+ *
+ * mv /a/b/c/d /a/b/c2/d2
+ * mv /a/b/c /a/b/c2/d2/cc
+ *
+ * "c" has lower inode number, but we can't move it (2nd mv operation)
+ * before we move "d", which has higher inode number.
+ *
+ * So we just memorize which move/rename operations must be performed
+ * later when their respective parent is processed and moved/renamed.
+ */
+
+ /* Indexed by parent directory inode number. */
+ struct rb_root pending_dir_moves;
+
+ /*
+ * Reverse index, indexed by the inode number of a directory that
+ * is waiting for the move/rename of its immediate parent before its
+ * own move/rename can be performed.
+ */
+ struct rb_root waiting_dir_moves;
+};
+
+struct pending_dir_move {
+ struct rb_node node;
+ struct list_head list;
+ u64 parent_ino;
+ u64 ino;
+ u64 gen;
+ struct list_head update_refs;
+};
+
+struct waiting_dir_move {
+ struct rb_node node;
+ u64 ino;
};
struct name_cache_entry {
@@ -144,6 +212,8 @@ struct name_cache_entry {
char name[];
};
+static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
+
static int need_send_hole(struct send_ctx *sctx)
{
return (sctx->parent_root && !sctx->cur_inode_new &&
@@ -1897,6 +1967,7 @@ static void name_cache_free(struct send_ctx *sctx)
*/
static int __get_cur_name_and_parent(struct send_ctx *sctx,
u64 ino, u64 gen,
+ int skip_name_cache,
u64 *parent_ino,
u64 *parent_gen,
struct fs_path *dest)
@@ -1906,6 +1977,8 @@ static int __get_cur_name_and_parent(struct send_ctx *sctx,
struct btrfs_path *path = NULL;
struct name_cache_entry *nce = NULL;
+ if (skip_name_cache)
+ goto get_ref;
/*
* First check if we already did a call to this function with the same
* ino/gen. If yes, check if the cache entry is still up-to-date. If yes
@@ -1950,11 +2023,12 @@ static int __get_cur_name_and_parent(struct send_ctx *sctx,
goto out_cache;
}
+get_ref:
/*
* Depending on whether the inode was already processed or not, use
* send_root or parent_root for ref lookup.
*/
- if (ino < sctx->send_progress)
+ if (ino < sctx->send_progress && !skip_name_cache)
ret = get_first_ref(sctx->send_root, ino,
parent_ino, parent_gen, dest);
else
@@ -1978,6 +2052,8 @@ static int __get_cur_name_and_parent(struct send_ctx *sctx,
goto out;
ret = 1;
}
+ if (skip_name_cache)
+ goto out;
out_cache:
/*
@@ -2045,6 +2121,9 @@ static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
u64 parent_inode = 0;
u64 parent_gen = 0;
int stop = 0;
+ u64 start_ino = ino;
+ u64 start_gen = gen;
+ int skip_name_cache = 0;
name = fs_path_alloc();
if (!name) {
@@ -2052,19 +2131,32 @@ static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
goto out;
}
+ if (is_waiting_for_move(sctx, ino))
+ skip_name_cache = 1;
+
+again:
dest->reversed = 1;
fs_path_reset(dest);
while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
fs_path_reset(name);
- ret = __get_cur_name_and_parent(sctx, ino, gen,
+ ret = __get_cur_name_and_parent(sctx, ino, gen, skip_name_cache,
&parent_inode, &parent_gen, name);
if (ret < 0)
goto out;
if (ret)
stop = 1;
+ if (!skip_name_cache &&
+ is_waiting_for_move(sctx, parent_inode)) {
+ ino = start_ino;
+ gen = start_gen;
+ stop = 0;
+ skip_name_cache = 1;
+ goto again;
+ }
+
ret = fs_path_add_path(dest, name);
if (ret < 0)
goto out;
@@ -2636,10 +2728,349 @@ out:
return ret;
}
+static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
+{
+ struct rb_node *n = sctx->waiting_dir_moves.rb_node;
+ struct waiting_dir_move *entry;
+
+ while (n) {
+ entry = rb_entry(n, struct waiting_dir_move, node);
+ if (ino < entry->ino)
+ n = n->rb_left;
+ else if (ino > entry->ino)
+ n = n->rb_right;
+ else
+ return 1;
+ }
+ return 0;
+}
+
+static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino)
+{
+ struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
+ struct rb_node *parent = NULL;
+ struct waiting_dir_move *entry, *dm;
+
+ dm = kmalloc(sizeof(*dm), GFP_NOFS);
+ if (!dm)
+ return -ENOMEM;
+ dm->ino = ino;
+
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct waiting_dir_move, node);
+ if (ino < entry->ino) {
+ p = &(*p)->rb_left;
+ } else if (ino > entry->ino) {
+ p = &(*p)->rb_right;
+ } else {
+ kfree(dm);
+ return -EEXIST;
+ }
+ }
+
+ rb_link_node(&dm->node, parent, p);
+ rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
+ return 0;
+}
+
+#ifdef CONFIG_BTRFS_ASSERT
+
+static int del_waiting_dir_move(struct send_ctx *sctx, u64 ino)
+{
+ struct rb_node *n = sctx->waiting_dir_moves.rb_node;
+ struct waiting_dir_move *entry;
+
+ while (n) {
+ entry = rb_entry(n, struct waiting_dir_move, node);
+ if (ino < entry->ino) {
+ n = n->rb_left;
+ } else if (ino > entry->ino) {
+ n = n->rb_right;
+ } else {
+ rb_erase(&entry->node, &sctx->waiting_dir_moves);
+ kfree(entry);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+#endif
+
+static int add_pending_dir_move(struct send_ctx *sctx, u64 parent_ino)
+{
+ struct rb_node **p = &sctx->pending_dir_moves.rb_node;
+ struct rb_node *parent = NULL;
+ struct pending_dir_move *entry, *pm;
+ struct recorded_ref *cur;
+ int exists = 0;
+ int ret;
+
+ pm = kmalloc(sizeof(*pm), GFP_NOFS);
+ if (!pm)
+ return -ENOMEM;
+ pm->parent_ino = parent_ino;
+ pm->ino = sctx->cur_ino;
+ pm->gen = sctx->cur_inode_gen;
+ INIT_LIST_HEAD(&pm->list);
+ INIT_LIST_HEAD(&pm->update_refs);
+ RB_CLEAR_NODE(&pm->node);
+
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct pending_dir_move, node);
+ if (parent_ino < entry->parent_ino) {
+ p = &(*p)->rb_left;
+ } else if (parent_ino > entry->parent_ino) {
+ p = &(*p)->rb_right;
+ } else {
+ exists = 1;
+ break;
+ }
+ }
+
+ list_for_each_entry(cur, &sctx->deleted_refs, list) {
+ ret = dup_ref(cur, &pm->update_refs);
+ if (ret < 0)
+ goto out;
+ }
+ list_for_each_entry(cur, &sctx->new_refs, list) {
+ ret = dup_ref(cur, &pm->update_refs);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = add_waiting_dir_move(sctx, pm->ino);
+ if (ret)
+ goto out;
+
+ if (exists) {
+ list_add_tail(&pm->list, &entry->list);
+ } else {
+ rb_link_node(&pm->node, parent, p);
+ rb_insert_color(&pm->node, &sctx->pending_dir_moves);
+ }
+ ret = 0;
+out:
+ if (ret) {
+ __free_recorded_refs(&pm->update_refs);
+ kfree(pm);
+ }
+ return ret;
+}
+
+static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
+ u64 parent_ino)
+{
+ struct rb_node *n = sctx->pending_dir_moves.rb_node;
+ struct pending_dir_move *entry;
+
+ while (n) {
+ entry = rb_entry(n, struct pending_dir_move, node);
+ if (parent_ino < entry->parent_ino)
+ n = n->rb_left;
+ else if (parent_ino > entry->parent_ino)
+ n = n->rb_right;
+ else
+ return entry;
+ }
+ return NULL;
+}
+
+static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
+{
+ struct fs_path *from_path = NULL;
+ struct fs_path *to_path = NULL;
+ u64 orig_progress = sctx->send_progress;
+ struct recorded_ref *cur;
+ int ret;
+
+ from_path = fs_path_alloc();
+ if (!from_path)
+ return -ENOMEM;
+
+ sctx->send_progress = pm->ino;
+ ret = get_cur_path(sctx, pm->ino, pm->gen, from_path);
+ if (ret < 0)
+ goto out;
+
+ to_path = fs_path_alloc();
+ if (!to_path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ sctx->send_progress = sctx->cur_ino + 1;
+ ASSERT(del_waiting_dir_move(sctx, pm->ino) == 0);
+ ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
+ if (ret < 0)
+ goto out;
+
+ ret = send_rename(sctx, from_path, to_path);
+ if (ret < 0)
+ goto out;
+
+ ret = send_utimes(sctx, pm->ino, pm->gen);
+ if (ret < 0)
+ goto out;
+
+ /*
+ * After rename/move, need to update the utimes of both new parent(s)
+ * and old parent(s).
+ */
+ list_for_each_entry(cur, &pm->update_refs, list) {
+ ret = send_utimes(sctx, cur->dir, cur->dir_gen);
+ if (ret < 0)
+ goto out;
+ }
+
+out:
+ fs_path_free(from_path);
+ fs_path_free(to_path);
+ sctx->send_progress = orig_progress;
+
+ return ret;
+}
+
+static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
+{
+ if (!list_empty(&m->list))
+ list_del(&m->list);
+ if (!RB_EMPTY_NODE(&m->node))
+ rb_erase(&m->node, &sctx->pending_dir_moves);
+ __free_recorded_refs(&m->update_refs);
+ kfree(m);
+}
+
+static void tail_append_pending_moves(struct pending_dir_move *moves,
+ struct list_head *stack)
+{
+ if (list_empty(&moves->list)) {
+ list_add_tail(&moves->list, stack);
+ } else {
+ LIST_HEAD(list);
+ list_splice_init(&moves->list, &list);
+ list_add_tail(&moves->list, stack);
+ list_splice_tail(&list, stack);
+ }
+}
+
+static int apply_children_dir_moves(struct send_ctx *sctx)
+{
+ struct pending_dir_move *pm;
+ struct list_head stack;
+ u64 parent_ino = sctx->cur_ino;
+ int ret = 0;
+
+ pm = get_pending_dir_moves(sctx, parent_ino);
+ if (!pm)
+ return 0;
+
+ INIT_LIST_HEAD(&stack);
+ tail_append_pending_moves(pm, &stack);
+
+ while (!list_empty(&stack)) {
+ pm = list_first_entry(&stack, struct pending_dir_move, list);
+ parent_ino = pm->ino;
+ ret = apply_dir_move(sctx, pm);
+ free_pending_move(sctx, pm);
+ if (ret)
+ goto out;
+ pm = get_pending_dir_moves(sctx, parent_ino);
+ if (pm)
+ tail_append_pending_moves(pm, &stack);
+ }
+ return 0;
+
+out:
+ while (!list_empty(&stack)) {
+ pm = list_first_entry(&stack, struct pending_dir_move, list);
+ free_pending_move(sctx, pm);
+ }
+ return ret;
+}
+
+static int wait_for_parent_move(struct send_ctx *sctx,
+ struct recorded_ref *parent_ref)
+{
+ int ret;
+ u64 ino = parent_ref->dir;
+ u64 parent_ino_before, parent_ino_after;
+ u64 new_gen, old_gen;
+ struct fs_path *path_before = NULL;
+ struct fs_path *path_after = NULL;
+ int len1, len2;
+
+ if (parent_ref->dir <= sctx->cur_ino)
+ return 0;
+
+ if (is_waiting_for_move(sctx, ino))
+ return 1;
+
+ ret = get_inode_info(sctx->parent_root, ino, NULL, &old_gen,
+ NULL, NULL, NULL, NULL);
+ if (ret == -ENOENT)
+ return 0;
+ else if (ret < 0)
+ return ret;
+
+ ret = get_inode_info(sctx->send_root, ino, NULL, &new_gen,
+ NULL, NULL, NULL, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (new_gen != old_gen)
+ return 0;
+
+ path_before = fs_path_alloc();
+ if (!path_before)
+ return -ENOMEM;
+
+ ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
+ NULL, path_before);
+ if (ret == -ENOENT) {
+ ret = 0;
+ goto out;
+ } else if (ret < 0) {
+ goto out;
+ }
+
+ path_after = fs_path_alloc();
+ if (!path_after) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
+ NULL, path_after);
+ if (ret == -ENOENT) {
+ ret = 0;
+ goto out;
+ } else if (ret < 0) {
+ goto out;
+ }
+
+ len1 = fs_path_len(path_before);
+ len2 = fs_path_len(path_after);
+ if ((parent_ino_before != parent_ino_after) && (len1 != len2 ||
+ memcmp(path_before->start, path_after->start, len1))) {
+ ret = 1;
+ goto out;
+ }
+ ret = 0;
+
+out:
+ fs_path_free(path_before);
+ fs_path_free(path_after);
+
+ return ret;
+}
+
/*
* This does all the move/link/unlink/rmdir magic.
*/
-static int process_recorded_refs(struct send_ctx *sctx)
+static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
{
int ret = 0;
struct recorded_ref *cur;
@@ -2788,11 +3219,17 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
* dirs, we always have one new and one deleted
* ref. The deleted ref is ignored later.
*/
- ret = send_rename(sctx, valid_path,
- cur->full_path);
- if (ret < 0)
- goto out;
- ret = fs_path_copy(valid_path, cur->full_path);
+ if (wait_for_parent_move(sctx, cur)) {
+ ret = add_pending_dir_move(sctx,
+ cur->dir);
+ *pending_move = 1;
+ } else {
+ ret = send_rename(sctx, valid_path,
+ cur->full_path);
+ if (!ret)
+ ret = fs_path_copy(valid_path,
+ cur->full_path);
+ }
if (ret < 0)
goto out;
} else {
@@ -3161,6 +3598,7 @@ static int process_all_refs(struct send_ctx *sctx,
struct extent_buffer *eb;
int slot;
iterate_inode_ref_t cb;
+ int pending_move = 0;
path = alloc_path_for_send();
if (!path)
@@ -3204,7 +3642,9 @@ static int process_all_refs(struct send_ctx *sctx,
}
btrfs_release_path(path);
- ret = process_recorded_refs(sctx);
+ ret = process_recorded_refs(sctx, &pending_move);
+ /* Only applicable to an incremental send. */
+ ASSERT(pending_move == 0);
out:
btrfs_free_path(path);
@@ -4165,7 +4605,9 @@ out:
return ret;
}
-static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end)
+static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
+ int *pending_move,
+ int *refs_processed)
{
int ret = 0;
@@ -4177,17 +4619,11 @@ static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end)
if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
goto out;
- ret = process_recorded_refs(sctx);
+ ret = process_recorded_refs(sctx, pending_move);
if (ret < 0)
goto out;
- /*
- * We have processed the refs and thus need to advance send_progress.
- * Now, calls to get_cur_xxx will take the updated refs of the current
- * inode into account.
- */
- sctx->send_progress = sctx->cur_ino + 1;
-
+ *refs_processed = 1;
out:
return ret;
}
@@ -4203,11 +4639,29 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
u64 right_gid;
int need_chmod = 0;
int need_chown = 0;
+ int pending_move = 0;
+ int refs_processed = 0;
- ret = process_recorded_refs_if_needed(sctx, at_end);
+ ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
+ &refs_processed);
if (ret < 0)
goto out;
+ /*
+ * We have processed the refs and thus need to advance send_progress.
+ * Now, calls to get_cur_xxx will take the updated refs of the current
+ * inode into account.
+ *
+ * On the other hand, if our current inode is a directory and couldn't
+ * be moved/renamed because its parent was renamed/moved too and it has
+ * a higher inode number, we can only move/rename our current inode
+ * after we moved/renamed its parent. Therefore in this case operate on
+ * the old path (pre move/rename) of our current inode, and the
+ * move/rename will be performed later.
+ */
+ if (refs_processed && !pending_move)
+ sctx->send_progress = sctx->cur_ino + 1;
+
if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
goto out;
if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
@@ -4269,9 +4723,21 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
}
/*
- * Need to send that every time, no matter if it actually changed
- * between the two trees as we have done changes to the inode before.
+ * If other directory inodes depended on our current directory
+ * inode's move/rename, now do their move/rename operations.
*/
+ if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
+ ret = apply_children_dir_moves(sctx);
+ if (ret)
+ goto out;
+ }
+
+ /*
+ * Need to send that every time, no matter if it actually
+ * changed between the two trees as we have done changes to
+ * the inode before.
+ */
+ sctx->send_progress = sctx->cur_ino + 1;
ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
if (ret < 0)
goto out;
@@ -4839,6 +5305,9 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
goto out;
}
+ sctx->pending_dir_moves = RB_ROOT;
+ sctx->waiting_dir_moves = RB_ROOT;
+
sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
(arg->clone_sources_count + 1));
if (!sctx->clone_roots) {
@@ -4947,6 +5416,34 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
}
out:
+ WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
+ while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
+ struct rb_node *n;
+ struct pending_dir_move *pm;
+
+ n = rb_first(&sctx->pending_dir_moves);
+ pm = rb_entry(n, struct pending_dir_move, node);
+ while (!list_empty(&pm->list)) {
+ struct pending_dir_move *pm2;
+
+ pm2 = list_first_entry(&pm->list,
+ struct pending_dir_move, list);
+ free_pending_move(sctx, pm2);
+ }
+ free_pending_move(sctx, pm);
+ }
+
+ WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
+ while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
+ struct rb_node *n;
+ struct waiting_dir_move *dm;
+
+ n = rb_first(&sctx->waiting_dir_moves);
+ dm = rb_entry(n, struct waiting_dir_move, node);
+ rb_erase(&dm->node, &sctx->waiting_dir_moves);
+ kfree(dm);
+ }
+
if (sort_clone_roots) {
for (i = 0; i < sctx->clone_roots_cnt; i++)
btrfs_root_dec_send_in_progress(