Use unaligned access helper for code that potentially or actually
accesses data that come from on-disk structures. This is for image or
chunk restore. This may pessimize some cases but is in general safer on
strict alignment architectures and has no effect on other architectures.
Related issue #770.
Signed-off-by: David Sterba <dsterba@suse.com>
There are quite some variable shadowing in btrfs-progs, most of them are
just reusing some common names like tmp.
And those are quite safe and the shadowed one are even different type.
But there are some exceptions:
- @end in traverse_tree_blocks()
There is already an @end with the same type, but a different meaning
(the end of the current extent buffer passed in).
Just rename it to @child_end.
- @start in generate_new_data_csums_range()
Just rename it to @csum_start.
- @size of fixup_chunk_tree_block()
This one is particularly bad, we declare a local @size and initialize
it to -1, then before we really utilize the variable @size, we
immediately reset it to 0, then pass it to logical_to_physical().
Then there is a location to check if @size is -1, which will always be
true.
According to the code in logical_to_physical(), @size would be clamped
down by its original value, thus our local @size will always be 0.
This patch would rename the local @size to @found_size, and only set
it to -1.
The call site is only to pass something as logical_to_physical()
requires a non-NULL pointer.
We don't really need to bother the returned value.
- duplicated @ref declaration in run_delayed_tree_ref()
- duplicated @super_flags in change_meta_csums()
Just delete the duplicated one.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the kernel we've added a control struct to handle the different
checks we want to do on extent buffers when we read them. Update our
copy of read_tree_block to take this as an argument, then update all of
the callers to use the new structure.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This simply zero's out the path, and this is used everywhere we use a
stack path. Drop this usage and simply init the path's to empty instead
of using a function to do the memset.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The remaining part of restore functionality starting from
restore_metadump() has been factored out. Same incremental set of
changes so the diff is not clean.
Signed-off-by: David Sterba <dsterba@suse.com>
The functionality of create and restore is all in main.c, split the
create functionality first. This is not the cleaniest diff to do it, the
functions are entangled and the final result is from several compile and
edit cycles.
Signed-off-by: David Sterba <dsterba@suse.com>
The struct open_ctree_flags currently holds arguments for
open_ctree_fs_info(), it can be confusing when mixed with a local variable
named open_ctree_flags as below in the function cmd_inspect_dump_tree().
cmd_inspect_dump_tree()
::
struct open_ctree_flags ocf = { 0 };
::
unsigned open_ctree_flags;
So rename struct open_ctree_flags to struct open_ctree_args.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This syncs tree-checker.c from the kernel. The main modification was to
add a open ctree flag to skip the deeper leaf checks, and plumbing this
through tree-checker.c. We need this for things like fsck or
btrfs-image that need to work with slightly corrupted file systems, and
these checks simply make us unable to look at the corrupted blocks.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The in-kernel version of read_tree_block adds some extra sanity checks
to make sure we don't return blocks that don't match what we expect.
This includes the owning root, the level, and the expected first key.
We don't actually do these checks in btrfs-progs, however kernel code
we're going to sync will expect this calling convention, so update it to
match the in-kernel code and then update all the callers.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is a bit larger than the previous syncs, because we use
extent_io_tree's everywhere. There's a lot of stuff added to
kerncompat.h, and then I went through and cleaned up all the API
changes, which were
- extent_io_tree_init takes an fs_info and an owner now.
- extent_io_tree_cleanup is now extent_io_tree_release.
- set_extent_dirty takes a gfpmask.
- clear_extent_dirty takes a cached_state.
- find_first_extent_bit takes a cached_state.
The diffstat looks insane for this, but keep in mind extent-io-tree.c
and extent-io-tree.h are ~2000 loc just by themselves.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch syncs file-item.h into btrfs-progs. This carries with it an
API change for btrfs_del_csums, which takes a root argument in the
kernel, so all callsites have been updated accordingly.
I didn't sync file-item.c because it carries with it a bunch of bio
related helpers which are difficult to adapt to the kernel.
Additionally there's a few helpers in the local copy of file-item.c that
aren't in the kernel that are required for different tools.
This requires more cleanups in both the kernel and progs in order to
sync file-item.c, so for now just do file-item.h in order to pull things
out of ctree.h.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We want to keep this file locally as we want to be uptodate with
upstream, so we can build btrfs-progs regardless of which kernel is
currently installed. Sync this with the upstream version and put it in
kernel-shared/uapi to maintain some semblance of where this file comes
from.
There are some changes that need to be synced back to kernel. A local
definition of static_assert is used to avoid compilation problems on gcc
(< 9) due to mandatory 2nd parameter.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While syncing messages.[ch] I had to back out the ASSERT() code in
kerncompat.h, which means we now rely on the kernel code for ASSERT().
In order to maintain some semblance of separation introduce UASSERT()
and use that in all the purely userspace code.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The *64 interfaces, such as fstat64, off64_t, etc, are legacy interfaces
created at a time when 64-bit file support was still new. They are
generally exposed when defining a macro named _LARGEFILE64_SOURCE, as
e.g. the glibc docs[0] say.
The modern way to utilise largefile support, is to continue to use the
regular interfaces (off_t, fstat, ..), and define _FILE_OFFSET_BITS=64.
We already use the autoconf macro AC_SYS_LARGEFILE[1] which arranges this
and sets this macro for us. Therefore, we can utilise the non-64 names
without fear of breaking on 32-bit systems.
This fixes the build against musl libc, ever since musl dropped the
*64 compat from interfaces by default[2] just for _GNU_SOURCE, unless
_LARGEFILE64_SOURCE is defined. However, there are plans for a future
removal of the whole *64 header API, and that workaround (adding another
define) might cease to exist.
So, rename all *64 API use to the regular non-suffixed names. For
consistency, rename the internal functions that were *64 named
(lstat64_path, ..) too.
This should have no regressions on any platform.
[0]: https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html#index-_005fLARGEFILE64_005fSOURCE
[1]: https://www.gnu.org/software/autoconf/manual/autoconf-2.67/html_node/System-Services.html
[2]: 25e6fee27f
Pull-request: #615
Signed-off-by: psykose <alice@ayaya.dev>
Signed-off-by: David Sterba <dsterba@suse.com>
After previous change to usage() that now has the return code, there's
no purpose of the print_usage() wrapper so it can be removed.
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Currently cli/009 test case failed with different exit number:
====== RUN CHECK /home/adam/btrfs-progs/btrfstune --help
usage: btrfstune [options] device
[...]
failed: /home/adam/btrfs-progs/btrfstune --help
test failed for case 009-btrfstune
[CAUSE]
In tune/main.c, we have the following call on usage():
static void print_usage(int ret)
{
usage(&tune_cmd);
exit(ret);
}
However usage() itself would always call exit(1):
void usage(const struct cmd_struct *cmd)
{
usage_command_usagestr(cmd->usagestr, NULL, 0, true, true);
exit(1);
}
This makes prevents any caller of usage() to modify its exit number.
[FIX]
Add a new argument @error for print_usage(), so we can properly return 0
for -h/--help usage.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Prepare a single location that will detect or set accelerated versions
of hash algorithms. Right now it's the crc32c, blake2 and sha256 do
an if-else switch while crc32c sets a function pointer.
Signed-off-by: David Sterba <dsterba@suse.com>
[WARNING]
Clang 15.0.7 warns about several unused variables:
kernel-shared/zoned.c:829:6: warning: variable 'num_sequential' set but not used [-Wunused-but-set-variable]
u32 num_sequential = 0, num_conventional = 0;
^
cmds/scrub.c:1174:6: warning: variable 'n_skip' set but not used [-Wunused-but-set-variable]
int n_skip = 0;
^
mkfs/main.c:493:6: warning: variable 'total_block_count' set but not used [-Wunused-but-set-variable]
u64 total_block_count = 0;
^
image/main.c:2246:6: warning: variable 'bytenr' set but not used [-Wunused-but-set-variable]
u64 bytenr = 0;
^
[CAUSE]
Most of them are just straightforward set but not used variables.
The only exception is total_block_count, which has commented out code
relying on it.
[FIX]
Just remove those variables, and for @total_block_count, also remove the
comments.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[WARNING]
Clang 15.0.7 gives the following warning:
image/main.c:95:2: warning: field '' with variable sized type 'union metadump_struct::(anonymous at image/main.c:95:2)' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
union {
^
[CAUSE]
The union contains meta_cluster, which variable sized:
struct meta_cluster {
struct meta_cluster_header header;
struct meta_cluster_item items[];
} __attribute__ ((__packed__));
Thus clang gives above warning since it's a GNU extension.
[FIX]
Just move the union to the end of the structure.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[FALSE ALERT]
Unlike gcc, clang doesn't really understand the comments, thus it's
reportings tons of fall through related errors:
cmds/reflink.c:124:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
case 'r':
^
cmds/reflink.c:124:3: note: insert '__attribute__((fallthrough));' to silence this warning
case 'r':
^
__attribute__((fallthrough));
cmds/reflink.c:124:3: note: insert 'break;' to avoid fall-through
case 'r':
^
break;
[CAUSE]
Although gcc is fine with /* fallthrough */ comments, clang is not.
[FIX]
So just introduce a fallthrough macro to handle the situation properly,
and use that macro instead.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We're using btrfs_item_nr_offset(leaf, 0) to get the start of the leaf
data in the kernel, we don't have btrfs_leaf_data. Replace all
occurrences of btrfs_leaf_data() with btrfs_item_nr_offset(leaf, 0) in
order to make syncing accessors.[ch] easier. ctree.c will be synced
later, so this is simply an intermediate step.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we sync the kernel we're going to pull in the fs.h dependency,
which defines BLOCK_SIZE/BLOCK_MASK. Avoid this conflict by renaming
the image definitions with the IMAGE_ prefix.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Print warning when one of the following is requested by some command
line option:
- btrfstune -b: conversion to block-group-tree
- mkfs.btrfs --num-global-roots: extent-tree-v2
- btrfs-image -d: dump image with data
Issue: #523
Signed-off-by: David Sterba <dsterba@suse.com>
There's a group of helpers to read device size, the btrfs_device_size
should be one of them. Rename it and so minor cleanup.
Signed-off-by: David Sterba <dsterba@suse.com>
The (unsigned long long) type casts can be dropped, printf understands
%llu and u64 and does not warn. In cases where the type is not u64 keep
the cast.
Signed-off-by: David Sterba <dsterba@suse.com>
The preferred order:
- system headers
- standard headers
- libraries
- kernel library
- kernel shared
- common headers
- other tools
- own headers
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Shinichiro reported that "mkfs.btrfs -m DUP" is doing repeated write
into the device.
For non-zoned device this is not a big deal, but for zoned device this
is critical, as zoned device doesn't support overwrite at all.
[CAUSE]
The problem is related to write_and_map_eb() call, since commit
2a93728391 ("btrfs-progs: use write_data_to_disk() to replace
write_extent_to_disk()"), we call write_data_to_disk() for metadata
write back.
But the problem is, write_data_to_disk() will call btrfs_map_block()
with rw = WRITE.
By that btrfs_map_block() will always return all stripes, while in
write_data_to_disk() we also iterate through each mirror of the range.
This results above repeated writeback.
[FIX]
Fix this problem by completely remove @mirror argument
from write_data_to_disk().
With extra comments to explicitly show that function will write to
all mirrors.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 2a93728391 ("btrfs-progs: use write_data_to_disk() to replace write_extent_to_disk()")
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function read_extent_from_disk() is only a wrapper to read tree
block.
And read_extent_data() is just a while loop to eliminate short read
caused by stripe boundary.
In fact, a lot of call sites of read_extent_data() are either reading
metadata (thus no possible short read) or doing extra loop by
themselves.
This patch will replace those two functions with read_data_from_disk(),
making it the only entrance for data/metadata read.
And update read_data_from_disk() to return the read bytes, so caller can
do a simple while loop.
For the few callers of read_extent_data(), open-code a small while loop
for them.
This will allow later RAID56 read repair using P/Q much easier.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we change the size of the btrfs_header we're going to need to
change how these helpers calculate where to find the start of items or
block ptrs. To prepare for that make these helpers take the
extent_buffer as an argument so we can do the appropriate math based on
the version type.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that all callers are using the _nr variations we can simply rename
these helpers to btrfs_item_##member/btrfs_set_item_##member and change
the actual item SETGET funcs to raw_item_##member/set_raw_item_##member
and then change all callers to drop the _nr part.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This matches how the kernel does it, simply pass in the slot and fix up
btrfs_file_extent_inline_item_len to use the btrfs_item_nr() helper and
the correct define. Fixup all the callers to use the slot now instead
of passing in the btrfs_item.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a lot of the following patterns
item = btrfs_item_nr(nr);
btrfs_set_item_*(eb, item, val);
btrfs_set_item_*(eb, btrfs_item_nr(nr), val);
in a lot of places in our code. Instead add _nr variations of these
helpers and convert all of the users to this new helper.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have this pattern in a lot of places
item = btrfs_item_nr(slot);
btrfs_item_size(leaf, item);
btrfs_item_offset(leaf, item);
when we could simply use
btrfs_item_size_nr(leaf, slot);
btrfs_item_offset_nr(leaf, slot);
Fix all callers of btrfs_item_size() and btrfs_item_offset() to use the
_nr variation of the helpers.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we switch to multiple global trees we'll need to access the
appropriate extent root depending on the block group or possibly root.
To handle this, use a helper in most places and then the actual root in
places where it is required. We will whittle down the direct accessors
with future patches, but this does the bulk of the preparatory work.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Extent tree v2 no longer tracks all allocated blocks on the file system,
so we'll have to default to walking trees to generate metadata images.
There's an annoying drawback with walking trees with btrfs-image where
we'll happily copy multiple blocks over and over again if there are
snapshots. Fix this by keeping track of blocks we've seen and simply
skipping blocks that we've already queued up for copying.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are a lot of call sites where we use the following code snippet:
u8 super_block_data[BTRFS_SUPER_INFO_SIZE];
struct btrfs_super_block *sb;
u64 ret;
sb = (struct btrfs_super_block *)super_block_data;
The reason for this is, structure btrfs_super_block was smaller than
BTRFS_SUPER_INFO_SIZE.
Thus for anything with csum involved, we have to use a proper 4K buffer.
Since the recent unification of sizeof(struct btrfs_super_block), we no
longer need such workaround, and can use struct btrfs_super_block
directly to do any operation.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When compiling btrfs-progs on 32bit x86 using GCC 11.1.0, there are
several warnings:
In file included from ./common/utils.h:30,
from check/main.c:36:
check/main.c: In function 'run_next_block':
./common/messages.h:42:31: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'u32' {aka 'unsigned int'} [-Wformat=]
42 | __btrfs_error((fmt), ##__VA_ARGS__); \
| ^~~~~
check/main.c:6496:33: note: in expansion of macro 'error'
6496 | error(
| ^~~~~
In file included from ./common/utils.h:30,
from kernel-shared/volumes.c:32:
kernel-shared/volumes.c: In function 'btrfs_check_chunk_valid':
./common/messages.h:42:31: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'u32' {aka 'unsigned int'} [-Wformat=]
42 | __btrfs_error((fmt), ##__VA_ARGS__); \
| ^~~~~
kernel-shared/volumes.c:2052:17: note: in expansion of macro 'error'
2052 | error("invalid chunk item size, have %u expect [%zu, %lu)",
| ^~~~~
image/main.c: In function 'search_for_chunk_blocks':
./common/messages.h:42:31: warning: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'size_t' {aka 'unsigned int'} [-Wformat=]
42 | __btrfs_error((fmt), ##__VA_ARGS__); \
| ^~~~~
image/main.c:2122:33: note: in expansion of macro 'error'
2122 | error(
| ^~~~~
There are two types of problems:
- __BTRFS_LEAF_DATA_SIZE()
This macro has no type definition, making it behaves differently on
different arches.
Fix this by following kernel to use inline function to make its return
value fixed to u32.
- size_t related output
For x86_64 %lu is OK but not for x86.
Fix this by using %zu.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There is a report that, btrfstune can even work while the fs has transid
mismatch problems.
$ btrfstune -f -u /dev/sdb1
Current fsid: b2b5ae8d-4c49-45f0-b42e-46fe7dcfcb07
New fsid: b2b5ae8d-4c49-45f0-b42e-46fe7dcfcb07
Set superblock flag CHANGING_FSID
Change fsid in extents
parent transid verify failed on 792854528 wanted 20103 found 20091
parent transid verify failed on 792854528 wanted 20103 found 20091
parent transid verify failed on 792854528 wanted 20103 found 20091
Ignoring transid failure
parent transid verify failed on 792870912 wanted 20103 found 20091
parent transid verify failed on 792870912 wanted 20103 found 20091
parent transid verify failed on 792870912 wanted 20103 found 20091
Ignoring transid failure
parent transid verify failed on 792887296 wanted 20103 found 20091
parent transid verify failed on 792887296 wanted 20103 found 20091
parent transid verify failed on 792887296 wanted 20103 found 20091
Ignoring transid failure
ERROR: child eb corrupted: parent bytenr=38010880 item=69 parent level=1 child level=1
ERROR: failed to change UUID of metadata: -5
ERROR: btrfstune failed
This leaves a corrupted fs even more corrupted, and due to the extra
CHANGING_FSID flag, btrfs check will not even try to run on it:
Opening filesystem to check...
ERROR: Filesystem UUID change in progress
ERROR: cannot open file system
[CAUSE]
Unlike kernel, btrfs-progs has a less strict check on transid mismatch.
In read_tree_block() we will fall back to use the tree block even its
transid mismatch if we can't find any better copy.
However not all commands in btrfs-progs needs this feature, only
btrfs-check (which may fix the problem) and btrfs-restore (it just tries
to ignore any problems) really utilize this feature.
[FIX]
Introduce a new open ctree flag, OPEN_CTREE_ALLOW_TRANSID_MISMATCH, to
be explicit about whether we really want to ignore transid error.
Currently only btrfs-check and btrfs-restore will utilize this new flag.
Also add btrfs-image to allow opening such fs with transid error.
Link: https://www.reddit.com/r/btrfs/comments/pivpqk/failure_during_btrfstune_u/
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There is a small device size misalignment between the super block device
size and the device extent size:
total_bytes 10737418240 <<<
bytes_used 15097856
dev_item.total_bytes 10737418240
dev_item.bytes_used 1094713344
item 0 key (DEV_ITEMS DEV_ITEM 1) itemoff 16185 itemsize 98
devid 1 total_bytes 1095761920 bytes_used 1094713344
^^^^^^^^^^
[CAUSE]
In fixup_device_size(), we only reset superblock device item size, which
will be overwritten in write_dev_supers() using btrfs_device::total_bytes.
And it doesn't touch btrfs_superblock::total_bytes either.
[FIX]
So fix the small mismatch by also resetting btrfs_device::total_bytes,
btrfs_device::bytes_used and btrfs_superblock::total_bytes.
Thankfully since commit 73dd4e3c87 ("btrfs-progs: image: Don't modify
the chunk and device tree if the source dump is single device") single
device dump won't have such problem, but it's still worth for
multi-device dump.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With recent change to enlarge max_pending_size to 256M for data dump,
the decompress code requires quite a lot of memory, up to 256M * 4.
The reason is we're using wrapped uncompress() function call, which
needs the buffer to be large enough to contain the decompressed data.
This patch will re-work the decompress work to use inflate() which can
resume it decompression so that we can use a much smaller buffer size.
Use 512K as buffer size.
Now the memory consumption for restore is reduced to
cluster data size + 512K * nr_running_threads
Instead of the original one:
cluster data size + 1G * nr_running_threads
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This new experimental data dump feature will dump the whole image, not
only the existing tree blocks but also all its data extents(*).
This feature will rely on the new dump format (_DUmP_v1), as it needs
extra large extent size limit, and older btrfs-image dump can't handle
such large item/cluster size.
Since we're dumping all extents including data extents, for the restored
image there is no need to use any extra super block flags to inform
kernel.
Kernel should just treat the restored image as any ordinary btrfs.
This new feature will be hidden behind the experimental features, that's
to say, if --enable-experimental is not enabled, although we still have
the option, it will not do anything but output an error message.
*: The data extents will be dumped as is, that's to say, even for
preallocated extent, its (meaningless) data will be read out and
dumpped.
This behavior will cause extra space usage for the image, but we can
skip all the complex partially shared preallocated extent check.
Issue: #394
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
