Gcc version 9.1.1 reports:
In file included from /usr/include/string.h:494,
from kerncompat.h:25,
from ctree.h:26,
from send-utils.c:26:
In function ‘memset’,
inlined from ‘btrfs_read_root_item’ at send-utils.c:165:3,
inlined from ‘subvol_uuid_search2’ at send-utils.c:494:8:
/usr/include/bits/string_fortified.h:71:10: warning: ‘__builtin_memset’ offset [248, 439] from the object at ‘root_item’ is out of the bounds of referenced subobject ‘generation_v2’ with type ‘long long unsigned int’ at offset 239 [-Warray-bounds]
71 | return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
That's correct in case the intent is to overwrite just the generation_v2
member, but we want to zero the rest of the root item structure starting
from the generation_v2. No typecasts can obscure that from gcc so the
starting address is calculated as base pointer + member offset.
Signed-off-by: David Sterba <dsterba@suse.com>
Similar to the changes where strerror(errno) was converted, continue
with the remaining cases where the argument was stored in another
variable.
The savings in object size are about 4500 bytes:
$ size btrfs.old btrfs.new
text data bss dec hex filename
805055 24248 19748 849051 cf49b btrfs.old
804527 24248 19748 848523 cf28b btrfs.new
Signed-off-by: David Sterba <dsterba@suse.com>
Since function path_cat and path_cat3 are not used anymore, remove them.
They have been reprecated since version 4.0.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As btrfs is specific to Linux, %m can be used instead of strerror(errno)
in format strings. This has some size reduction benefits for embedded
systems.
glibc, musl, and uclibc-ng all support %m as a modifier to printf.
A quick glance at the BIONIC libc source indicates that it has
support for %m as well. BSDs and Windows do not but I do believe
them to be beyond the scope of btrfs-progs.
Compiled sizes on Ubuntu 16.04:
Before:
3916512 btrfs
233688 libbtrfs.so.0.1
4899 bcp
2367672 btrfs-convert
2208488 btrfs-corrupt-block
13302 btrfs-debugfs
2152160 btrfs-debug-tree
2136024 btrfs-find-root
2287592 btrfs-image
2144600 btrfs-map-logical
2130760 btrfs-select-super
2152608 btrfstune
2131760 btrfs-zero-log
2277752 mkfs.btrfs
9166 show-blocks
After:
3908744 btrfs
233256 libbtrfs.so.0.1
4899 bcp
2366560 btrfs-convert
2207432 btrfs-corrupt-block
13302 btrfs-debugfs
2151104 btrfs-debug-tree
2134968 btrfs-find-root
2281864 btrfs-image
2143536 btrfs-map-logical
2129704 btrfs-select-super
2151552 btrfstune
2130696 btrfs-zero-log
2276272 mkfs.btrfs
9166 show-blocks
Total savings: 23928 (24 kilo)bytes
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The return value fix to subvol_uuid_search changes the API semantics, we
must keep it compatible, so we introduce a v2 interface that returns the
negative error value in case of error. Library version bump will follow.
Signed-off-by: David Sterba <dsterba@suse.com>
On failure of memory allocation for a 'struct subvol_info', we would end
up dereferencing a NULL pointer. This commit fixes the issue by returning an
error encoded pointer.
Signed-off-by: Prasanth K S R <prasanth.ksr@dell.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit changes subvol_uuid_search() to return an error encoded
pointer on failure.
Signed-off-by: Prasanth K S R <prasanth.ksr@dell.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit fixes coverity defect CID 1328695.
Resolves-coverity-id: 1328695
Signed-off-by: Prasanth K S R <prasanth.ksr@dell.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Handle only negative values returned by ioctl syscalls, with exception
of the device remove. It returns positive values that are handled later.
Signed-off-by: David Sterba <dsterba@suse.com>
The optional argument to attribute 'deprecated' has been introduced in
gcc 4.5, and does not build on 4.4 which is still in use. The
recommended replacements are mentioned in the comment, not absolutely
necessary to repeat it via the attribute.
Reported-by: Amr El-Sharnoby <amr.elsharnoby@horizontechs.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Add versions of path_cat and path_cat3 that do not allocate the memory.
The unhandled memory allocations are still there.
Signed-off-by: David Sterba <dsterba@suse.cz>
The path bufferes should be PATH_MAX but BTRFS_PATH_NAME_MAX is shorter
due to embedding in 4k aligned structures.
The only reason to use BTRFS_PATH_NAME_MAX is for the respective
structures btrfs_ioctl_vol_args::name.
Signed-off-by: David Sterba <dsterba@suse.cz>
When using gcc 4.8.2, -Wmaybe-uninitialized will report root_item may be
used uninitialized.
Since root_item_valid variant is used to determine the root_item valid,
it's a false alert and to avoid the warning, just init it on allocation.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Commit "Btrfs-progs: make send/receive compatible with older kernels"
adds code that will become deprecated, let's clearly mark it in the
sources.
CC: Stefan Behrens <sbehrens@giantdisaster.de>
CC: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Some users complaint that with latest btrfs-progs, they will
fail to use send/receive. The problem is new tool will try
to use uuid tree while it dosen't work on older kernel.
Now we first check if we support uuid tree, if not we fall into
normal search as previous way.i copy most of codes from Alexander
Block's previous codes and did some adjustments to make it work.
Signed-off-by: Alexander Block <ablock84@googlemail.com>
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
This commit changes the btrfs send/receive commands to use the
UUID tree to map UUIDs to subvolumes, and to use the root tree
to map subvolume IDs to paths. Now these tools start fast and are
independent on the number of subvolules/snapshot that exist.
Before this commit, mapping UUIDs to subvolume IDs was an operation
with a high effort. The algorithm even had quadratic effort (based
on the number of existing subvolumes). E.g. with 15,000 subvolumes
it took much more than 5 minutes on a state of the art XEON CPU to
start btrfs send or receive before these tools were able to send or
receive the first byte).
Even linear effort instead of the current quadratic effort would be
too much since it would be a waste. And these data structures to
allow mapping UUIDs to subvolume IDs had been created every time a
btrfs send/receive instance was started.
It is much more efficient to maintain a searchable persistent data
structure in the filesystem, one that is updated whenever a
subvolume/snapshot is created and deleted, and when the received
subvolume UUID is set by the btrfs-receive tool.
Therefore kernel code was added that is able to maintain data
structures in the filesystem that allow to quickly search for a
given UUID and to retrieve data that is assigned to this UUID, like
which subvolume ID is related to this UUID.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Several tools like btrfs-send and btrfs-receive need to map a
subvolume ID to a filesystem path. The so far existing methods
in btrfs-list.c cause a horrible effort when performing this
operation (and the effort is dependent on the number of
existing subvolumes with quadratic effort). This commit adds a
function that is able to map a subvolume ID to a filesystem path
with an effort that is independent of the number of existing
subvolumes.
In addition to this function, a command line frontend is added as well:
btrfs inspect-internal subvolid-resolve <subvolid> <path>
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
There was no way to free the memory that was used for the
subvol_uuid_search functions. Since this is part of the libbtrfs,
add such a cleanup function.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
We missed to add the default subvolume, because it has no ROOT_BACKREF_ITEM.
This made get_parent always fail for direct decendants of the default
subvolume, resulting in lots of full streams where incremental streams were
requested.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Reviewed-by: Alexander Block <ablock84@googlemail.com>
The current code of list_subvols() has very bad scalability, if we want to
add new filter conditions or new sort methods, we have to modify lots of code.
Beside that, the most code of list_snapshots() is similar to list_subvols(),
So I restructure list_subvols(), and split the subvolume filter function,
the subvolume sort function and the output function from list_subvols().
In order to implement it, we defined some importtant structures:
struct btrfs_list_filter {
btrfs_list_filter_func filter_func;
void *data;
};
struct btrfs_list_comparer {
btrfs_list_comp_func comp_func;
int is_descending;
};
struct {
char *name;
char *column_name;
int need_print;
} btrfs_list_columns[];
If we want to add a new filter condition, we can choose a suitable filter
function, or implement a new filter function[1], and add it into a set of
the filters, and then pass the filter set into list_subvols(). We also can
mix several filters (just add those filters into the set, and pass the set
into list_subvols()) if the users specify two or more filter conditions.
The subvolume sort function is similar to the subvolume filter function. The
differentiation is the order of comparers in the array which is passed into
list_subvols() show us the priority of the sort methods.
The output function is different with the above two functions, we define a
array to manage all the columns that can be outputed, and use a member variant
(->need_print) to control the output of the relative column. Some columns are
outputed by default. But we can change it according to the requirement of the
users.
After appling this patch, we needn't implement a independent list_snapshots()
function, just pass a filter function which is used to identify the snapshot
into list_subvols().
[1]: If we implement new filter functions or compare functions, we must add
them into the array all_filter_funcs or the array all_comp_funcs, and modify
the relative enum variants(btrfs_list_filter_enum, btrfs_list_comp_enum).
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This patch fixed the following warning:
cmds-send.c:464:6: warning: ‘ret' may be used uninitialized in this function [-Wuninitialized]
crc32c.c:121:1: warning: control reaches end of non-void function [-Wreturn-type]
send-utils.c:69:11: warning: ‘comp' may be used uninitialized in this function [-Wuninitialized]
send-utils.c:126:6: warning: ‘comp' may be used uninitialized in this function [-Wuninitialized]
send-utils.c:99:22: warning: ‘entry' may be used uninitialized in this function [-Wuninitialized]
btrfs.c:261:2: warning: implicit declaration of function ‘crc32c_optimization_init' [-Wimplicit-function-declaration]
btrfs.c:105:2: warning: ‘cmd' may be used uninitialized in this function [-Wuninitialized]
restore.c:435:12: warning: ignoring return value of ‘ftruncate', declared with attribute warn_unused_result [-Wunused-result]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The initial btrfs send code was easily confused by relative paths and by
anything that wasn't in the root of the FS. This fixes it to take
relative paths.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Add user space commands for btrfs send/receive.
Signed-off-by: Alexander Block <ablock84@googlemail.com>
Reviewed-by: David Sterba <dave@jikos.cz>
Reviewed-by: Arne Jansen <sensille@gmx.net>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Reviewed-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
David Sterba