From 6657ce2de3cdb25b14fb0183b90366e3e577fb9a Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Mon, 24 Mar 2025 13:45:44 -0400
Subject: [PATCH] Migrate tool fixes
Migrate now works: there is an inconsequential free space inconsistency
after marking the new superblock (in migrate_superblock), which we're
hacking around with a fsck.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
c_src/cmd_format.c | 2 +-
c_src/cmd_migrate.c | 75 ++++++++++++++++++++++++++++-----------
c_src/posix_to_bcachefs.c | 36 +++++++++++--------
c_src/posix_to_bcachefs.h | 2 +-
4 files changed, 78 insertions(+), 37 deletions(-)
diff --git a/c_src/cmd_format.c b/c_src/cmd_format.c
index 7c0d1920..2d900f1e 100644
--- a/c_src/cmd_format.c
+++ b/c_src/cmd_format.c
@@ -121,7 +121,7 @@ void build_fs(struct bch_fs *c, const char *src_path)
if (!S_ISDIR(stat.st_mode))
die("%s is not a directory", src_path);
- copy_fs(c, src_fd, src_path, &s);
+ copy_fs(c, src_fd, src_path, &s, 0);
}
int cmd_format(int argc, char *argv[])
diff --git a/c_src/cmd_migrate.c b/c_src/cmd_migrate.c
index 924f874d..a0328ca8 100644
--- a/c_src/cmd_migrate.c
+++ b/c_src/cmd_migrate.c
@@ -252,16 +252,14 @@ static int migrate_fs(const char *fs_path,
free(sb);
- struct bch_opts opts = bch2_opts_empty();
- struct bch_fs *c = NULL;
char *path[1] = { dev->path };
+ struct bch_opts opts = bch2_opts_empty();
opt_set(opts, sb, sb_offset);
opt_set(opts, nostart, true);
opt_set(opts, noexcl, true);
- opt_set(opts, nostart, true);
- c = bch2_fs_open(path, 1, opts);
+ struct bch_fs *c = bch2_fs_open(path, 1, opts);
if (IS_ERR(c))
die("Error opening new filesystem: %s", bch2_err_str(PTR_ERR(c)));
@@ -269,10 +267,6 @@ static int migrate_fs(const char *fs_path,
if (ret)
die("Error allocating buckets_nouse: %s", bch2_err_str(ret));
- ret = bch2_fs_start(c);
- if (IS_ERR(c))
- die("Error starting new filesystem: %s", bch2_err_str(ret));
-
mark_unreserved_space(c, extents);
ret = bch2_fs_start(c);
@@ -286,7 +280,10 @@ static int migrate_fs(const char *fs_path,
.type = BCH_MIGRATE_migrate,
};
- copy_fs(c, fs_fd, fs_path, &s);
+ u64 reserve_start = round_up((format_opts.superblock_size * 2 + 8) << 9,
+ dev->opts.bucket_size);
+
+ copy_fs(c, fs_fd, fs_path, &s, reserve_start);
bch2_fs_stop(c);
@@ -378,7 +375,7 @@ static void migrate_superblock_usage(void)
int cmd_migrate_superblock(int argc, char *argv[])
{
char *dev = NULL;
- u64 offset = 0;
+ u64 sb_offset = 0;
int opt, ret;
while ((opt = getopt(argc, argv, "d:o:h")) != -1)
@@ -387,7 +384,7 @@ int cmd_migrate_superblock(int argc, char *argv[])
dev = optarg;
break;
case 'o':
- ret = kstrtou64(optarg, 10, &offset);
+ ret = kstrtou64(optarg, 10, &sb_offset);
if (ret)
die("Invalid offset");
break;
@@ -399,29 +396,67 @@ int cmd_migrate_superblock(int argc, char *argv[])
if (!dev)
die("Please specify a device");
- if (!offset)
+ if (!sb_offset)
die("Please specify offset of existing superblock");
int fd = xopen(dev, O_RDWR);
- struct bch_sb *sb = __bch2_super_read(fd, offset);
+ struct bch_sb *sb = __bch2_super_read(fd, sb_offset);
+ unsigned sb_size = 1U << sb->layout.sb_max_size_bits;
if (sb->layout.nr_superblocks >= ARRAY_SIZE(sb->layout.sb_offset))
die("Can't add superblock: no space left in superblock layout");
- unsigned i;
- for (i = 0; i < sb->layout.nr_superblocks; i++)
- if (le64_to_cpu(sb->layout.sb_offset[i]) == BCH_SB_SECTOR)
- die("Superblock layout already has default superblock");
+ for (unsigned i = 0; i < sb->layout.nr_superblocks; i++)
+ if (le64_to_cpu(sb->layout.sb_offset[i]) == BCH_SB_SECTOR ||
+ le64_to_cpu(sb->layout.sb_offset[i]) == BCH_SB_SECTOR + sb_size)
+ die("Superblock layout already has default superblocks");
- memmove(&sb->layout.sb_offset[1],
+ memmove(&sb->layout.sb_offset[2],
&sb->layout.sb_offset[0],
sb->layout.nr_superblocks * sizeof(u64));
- sb->layout.nr_superblocks++;
-
+ sb->layout.nr_superblocks += 2;
sb->layout.sb_offset[0] = cpu_to_le64(BCH_SB_SECTOR);
+ sb->layout.sb_offset[1] = cpu_to_le64(BCH_SB_SECTOR + sb_size);
bch2_super_write(fd, sb);
close(fd);
+ /* mark new superblocks */
+
+ struct bch_opts opts = bch2_opts_empty();
+ opt_set(opts, nostart, true);
+ opt_set(opts, sb, sb_offset);
+
+ struct bch_fs *c = bch2_fs_open(&dev, 1, opts);
+ ret = PTR_ERR_OR_ZERO(c) ?:
+ bch2_buckets_nouse_alloc(c);
+ if (ret)
+ die("error opening filesystem: %s", bch2_err_str(ret));
+
+ struct bch_dev *ca = c->devs[0];
+ for (u64 b = 0; bucket_to_sector(ca, b) < BCH_SB_SECTOR + sb_size * 2; b++)
+ set_bit(b, ca->buckets_nouse);
+
+ ret = bch2_fs_start(c);
+ if (ret)
+ die("Error starting filesystem: %s", bch2_err_str(ret));
+
+ bch2_fs_stop(c);
+
+ opts = bch2_opts_empty();
+ opt_set(opts, fsck, true);
+ opt_set(opts, fix_errors, true);
+
+ /*
+ * Hack: the free space counters are coming out wrong after marking the
+ * new superblock, but it's just the device counters so it's
+ * inconsequential:
+ */
+
+ c = bch2_fs_open(&dev, 1, opts);
+ ret = PTR_ERR_OR_ZERO(c);
+ if (ret)
+ die("error opening filesystem: %s", bch2_err_str(ret));
+ bch2_fs_stop(c);
return 0;
}
diff --git a/c_src/posix_to_bcachefs.c b/c_src/posix_to_bcachefs.c
index 9a681f7b..63aa0937 100644
--- a/c_src/posix_to_bcachefs.c
+++ b/c_src/posix_to_bcachefs.c
@@ -264,7 +264,8 @@ void copy_link(struct bch_fs *c, struct bch_inode_unpacked *dst,
static void copy_file(struct bch_fs *c, struct bch_inode_unpacked *dst,
int src_fd, u64 src_size,
- char *src_path, struct copy_fs_state *s)
+ char *src_path, struct copy_fs_state *s,
+ u64 reserve_start)
{
struct fiemap_iter iter;
struct fiemap_extent e;
@@ -295,11 +296,8 @@ static void copy_file(struct bch_fs *c, struct bch_inode_unpacked *dst,
continue;
}
- /*
- * if the data is below 1 MB, copy it so it doesn't conflict
- * with bcachefs's potentially larger superblock:
- */
- if (e.fe_physical < 1 << 20) {
+ /* If the data is in bcachefs's superblock region, copy it: */
+ if (e.fe_physical < reserve_start) {
copy_data(c, dst, src_fd, e.fe_logical,
e.fe_logical + min(src_size - e.fe_logical,
e.fe_length));
@@ -318,7 +316,8 @@ static void copy_file(struct bch_fs *c, struct bch_inode_unpacked *dst,
static void copy_dir(struct copy_fs_state *s,
struct bch_fs *c,
struct bch_inode_unpacked *dst,
- int src_fd, const char *src_path)
+ int src_fd, const char *src_path,
+ u64 reserve_start)
{
DIR *dir = fdopendir(src_fd);
struct dirent *d;
@@ -369,7 +368,7 @@ static void copy_dir(struct copy_fs_state *s,
switch (mode_to_type(stat.st_mode)) {
case DT_DIR:
fd = xopen(d->d_name, O_RDONLY|O_NOATIME);
- copy_dir(s, c, &inode, fd, child_path);
+ copy_dir(s, c, &inode, fd, child_path, reserve_start);
close(fd);
break;
case DT_REG:
@@ -377,7 +376,7 @@ static void copy_dir(struct copy_fs_state *s,
fd = xopen(d->d_name, O_RDONLY|O_NOATIME);
copy_file(c, &inode, fd, stat.st_size,
- child_path, s);
+ child_path, s, reserve_start);
close(fd);
break;
case DT_LNK:
@@ -409,7 +408,8 @@ next:
static void reserve_old_fs_space(struct bch_fs *c,
struct bch_inode_unpacked *root_inode,
- ranges *extents)
+ ranges *extents,
+ u64 reserve_start)
{
struct bch_dev *ca = c->devs[0];
struct bch_inode_unpacked dst;
@@ -422,14 +422,20 @@ static void reserve_old_fs_space(struct bch_fs *c,
ranges_sort_merge(extents);
- for_each_hole(iter, *extents, bucket_to_sector(ca, ca->mi.nbuckets) << 9, i)
- link_data(c, &dst, i.start, i.start, i.end - i.start);
+ for_each_hole(iter, *extents, bucket_to_sector(ca, ca->mi.nbuckets) << 9, i) {
+ if (i.end <= reserve_start)
+ continue;
+
+ u64 start = max(i.start, reserve_start);
+
+ link_data(c, &dst, start, start, i.end - start);
+ }
update_inode(c, &dst);
}
void copy_fs(struct bch_fs *c, int src_fd, const char *src_path,
- struct copy_fs_state *s)
+ struct copy_fs_state *s, u64 reserve_start)
{
syncfs(src_fd);
@@ -448,10 +454,10 @@ void copy_fs(struct bch_fs *c, int src_fd, const char *src_path,
/* now, copy: */
- copy_dir(s, c, &root_inode, src_fd, src_path);
+ copy_dir(s, c, &root_inode, src_fd, src_path, reserve_start);
if (BCH_MIGRATE_migrate == s->type)
- reserve_old_fs_space(c, &root_inode, &s->extents);
+ reserve_old_fs_space(c, &root_inode, &s->extents, reserve_start);
update_inode(c, &root_inode);
diff --git a/c_src/posix_to_bcachefs.h b/c_src/posix_to_bcachefs.h
index facb75ed..ed87366a 100644
--- a/c_src/posix_to_bcachefs.h
+++ b/c_src/posix_to_bcachefs.h
@@ -50,5 +50,5 @@ struct copy_fs_state {
* initialized (`hardlinks` is initialized with zeroes).
*/
void copy_fs(struct bch_fs *c, int src_fd, const char *src_path,
- struct copy_fs_state *s);
+ struct copy_fs_state *s, u64);
#endif /* _LIBBCACHE_H */