[BUG]
There is a bug report that btrfs driver caused hang during file read:
This breaks btrfs on the HiFive Unmatched.
=> pci enum
PCIE-0: Link up (Gen1-x8, Bus0)
=> nvme scan
=> load nvme 0:2 0x8c000000 /boot/dtb/sifive/hifive-unmatched-a00.dtb
[hangs]
[CAUSE]
The reporter provided some debug output:
read_extent_data: cur=615817216, orig_len=16384, cur_len=16384
read_extent_data: btrfs_map_block: cur_len=479944704; ret=0
read_extent_data: ret=0
read_extent_data: cur=615833600, orig_len=4096, cur_len=4096
read_extent_data: btrfs_map_block: cur_len=479928320; ret=0
Note the second and the last line, the @cur_len is 450+MiB, which is
almost a chunk size.
And inside __btrfs_map_block(), we limits the returned value to stripe
length, but that's depending on the chunk type:
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4 |
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP)) {
/* we limit the length of each bio to what fits in a stripe */
*length = min_t(u64, ce->size - offset,
map->stripe_len - stripe_offset);
} else {
*length = ce->size - offset;
}
This means, if the chunk is SINGLE profile, then we don't limit the
returned length at all, and even for other profiles, we can still return
a length much larger than the requested one.
[FIX]
Properly clamp the returned length, preventing it from returning a much
larger range than expected.
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[BUG]
Since btrfs supports single device RAID0 at mkfs time after btrfs-progs
v5.14, if we create a single device raid0 btrfs, and created a file
crossing stripe boundary:
# mkfs.btrfs -m dup -d raid0 test.img
# mount test.img mnt
# xfs_io -f -c "pwrite 0 128K" mnt/file
# umount mnt
Since btrfs is using 64K as stripe length, above 128K data write is
definitely going to cross at least one stripe boundary.
Then u-boot would fail to read above 128K file:
=> host bind 0 /home/adam/test.img
=> ls host 0
< > 131072 Fri Dec 30 00:18:25 2022 file
=> load host 0 0 file
BTRFS: An error occurred while reading file file
Failed to load 'file'
[CAUSE]
Unlike tree blocks read, data extent reads doesn't consider cases in which
one data extent can cross stripe boundary.
In read_data_extent(), we just call btrfs_map_block() once and read the
first mapped range.
And if the first mapped range is smaller than the desired range, it
would return error.
But since even single device btrfs can utilize RAID0 profiles, the first
mapped range can only be at most 64K for RAID0 profiles, and cause false
error.
[FIX]
Just like read_whole_eb(), we should call btrfs_map_block() in a loop
until we read all data.
Since we're here, also add extra error messages for the following cases:
- btrfs_map_block() failure
We already have the error message for it.
- Missing device
This should not happen, as we only support single device for now.
- __btrfs_devread() failure
With this bug fixed, btrfs driver of u-boot can properly read the above
128K file, and have the correct content:
=> host bind 0 /home/adam/test.img
=> ls host 0
< > 131072 Fri Dec 30 00:18:25 2022 file
=> load host 0 0 file
131072 bytes read in 0 ms
=> md5sum 0 0x20000
md5 for 00000000 ... 0001ffff ==> d48858312a922db7eb86377f638dbc9f
^^^ Above md5sum also matches.
Reported-by: Sam Winchenbach <swichenbach@tethers.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
When looking for a filesystem on a partition we should do so quietly. At
present if the filesystem is very small (e.g. 512 bytes) we get a host of
messages.
Update these to only show when debugging.
Signed-off-by: Simon Glass <sjg@chromium.org>
This line probably got in by mistake as there is no fs_mutex member in
the btrfs_fs_info struct.
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Fix diacritics in some instances of my name and change my e-mail address
to kabel@kernel.org.
Add corresponding .mailmap entries.
Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
After returning if ret <= 0 we know that ret > 0. No need to check it.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain>
Fix following two compile errors on big endian systems:
CC fs/btrfs/btrfs.o
In file included from include/linux/byteorder/big_endian.h:107,
from ./arch/powerpc/include/asm/byteorder.h:82,
from ./arch/powerpc/include/asm/bitops.h:8,
from include/linux/bitops.h:152,
from include/uuid.h:9,
from fs/btrfs/btrfs.c:10:
fs/btrfs/conv-funcs.h: In function ‘btrfs_key_to_disk’:
include/linux/byteorder/generic.h:90:21: error: ‘__cpu_to_le16’ undeclared (first use in this function); did you mean ‘__cpu_to_le16p’?
#define cpu_to_le16 __cpu_to_le16
^~~~~~~~~~~~~
fs/btrfs/conv-funcs.h:79:10: note: in expansion of macro ‘cpu_to_le16’
__u16: cpu_to_le16, \
^~~~~~~~~~~
CC fs/btrfs/compression.o
In file included from ./arch/powerpc/include/asm/unaligned.h:9,
from fs/btrfs/compression.c:16:
include/linux/unaligned/access_ok.h:6:19: error: redefinition of ‘get_unaligned_le16’
static inline u16 get_unaligned_le16(const void *p)
^~~~~~~~~~~~~~~~~~
In file included from fs/btrfs/ctree.h:16,
from fs/btrfs/btrfs.h:12,
from fs/btrfs/compression.c:8:
include/linux/unaligned/le_byteshift.h:40:19: note: previous definition of ‘get_unaligned_le16’ was here
static inline u16 get_unaligned_le16(const void *p)
^~~~~~~~~~~~~~~~~~
Include file asm/unaligned.h contains arch specific macros and functions
for unaligned access as opposite to linux/unaligned le_byteshift.h which
contains macros and functions specific to little endian systems only.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[BUG]
When passing a btrfs with NO_HOLE feature to U-boot, and if one file
contains holes, then the hash of the file is not correct in U-boot:
# mkfs.btrfs -f test.img # Since v5.15, mkfs defaults to NO_HOLES
# mount test.img /mnt/btrfs
# xfs_io -f -c "pwrite 0 4k" -c "pwrite 8k 4k" /mnt/btrfs/file
# md5sum /mnt/btrfs/file
277f3840b275c74d01e979ea9d75ac19 /mnt/btrfs/file
# umount /mnt/btrfs
# ./u-boot
=> host bind 0 /home/adam/test.img
=> ls host 0
< > 12288 Mon Dec 27 05:35:23 2021 file
=> load host 0 0x1000000 file
12288 bytes read in 0 ms
=> md5sum 0x1000000 0x3000
md5 for 01000000 ... 01002fff ==> 855ffdbe4d0ccc5acab92e1b5330e4c1
The md5sum doesn't match at all.
[CAUSE]
In U-boot btrfs implementation, the function btrfs_read_file() has the
following iteration for file extent iteration:
/* Read the aligned part */
while (cur < aligned_end) {
ret = lookup_data_extent(root, &path, ino, cur, &next_offset);
if (ret < 0)
goto out;
if (ret > 0) {
/* No next, direct exit */
if (!next_offset) {
ret = 0;
goto out;
}
}
/* Read file extent */
But for NO_HOLES features, hole extents will not have any extent item
for it.
Thus if @cur is at a hole, lookup_data_extent() will just return >0, and
update @next_offset.
But we still believe there is some data to read for @cur for ret > 0
case, causing we read extent data from the next file extent.
This means, what we do for above NO_HOLES btrfs is:
- Read 4K data from disk to file offset [0, 4K)
So far the data is still correct
- Read 4K data from disk to file offset [4K, 8K)
We didn't skip the 4K hole, but read the data at file offset [8K, 12K)
into file offset [4K, 8K).
This causes the checksum mismatch.
[FIX]
Add extra check to skip to the next non-hole range after
lookup_data_extent().
Signed-off-by: Qu Wenruo <wqu@suse.com>
This message comes up a lot when scanning filesystems. It suggests to the
user that there is some sort of error, but in fact there is no reason to
expect that a particular partition has a btrfs filesystem. Other
filesystems don't print this error.
Turn it into a debug message.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Qu Wenruo <wqu@suse.com>
BTRFS volume consists of a number of subvolumes which can be mounted separately
from each other. The top-level subvolume always exists even if no subvolumes
were created manually. A subvolume can be denoted as the default subvolume i.e.
the subvolume which is mounted by default.
The default "default subvolume" is the top-level one, but this is far from the
common practices used in the wild. For instance, openSUSE provides an OS
snapshot/rollback feature based on BTRFS. To achieve this, the actual OS root
filesystem is located into a separate subvolume which is "default" but not
"top-level". That means that the /boot/dtb/ directory is also located inside
this default subvolume instead of top-level one.
However, the existing btrfs u-boot driver always uses the top-level subvolume
as the filesystem root. This behaviour 1) is inconsistent with
mount /dev/sda1 /target
command, which mount the default subvolume 2) leads to the issues when
/boot/dtb cannot be found properly (see the reference).
This patch uses the default subvolume as the filesystem root to overcome
mentioned issues.
Reference: https://bugzilla.suse.com/show_bug.cgi?id=1185656
Signed-off-by: Matwey V. Kornilov <matwey.kornilov@gmail.com>
Fixes: f06bfcf54d ("fs: btrfs: Crossport open_ctree_fs_info() from btrfs-progs")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Since the ACPI-generation code makes use of UUIDs we typically need to
enabled UUID support for it to build. Add a new Kconfig condition.
Use it for BTRFS also.
Signed-off-by: Simon Glass <sjg@chromium.org>
The superblock buffer must be cache aligned, since it might be used
in DMA context, allocate it using ALLOC_CACHE_ALIGN_BUFFER() just
like it was done in btrfs_read_superblock() and read_tree_node().
This fixes this output on boot and non-working btrfs on iMX53:
CACHE: Misaligned operation at range [ced299d0, ced2a9d0]
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marek Behún <marek.behun@nic.cz>
Cc: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
There are some cases where decompressed sectors can have padding zeros.
In kernel code, we have lines to address such situation:
/*
* btrfs_getblock is doing a zero on the tail of the page too,
* but this will cover anything missing from the decompressed
* data.
*/
if (bytes < destlen)
memset(kaddr+bytes, 0, destlen-bytes);
kunmap_local(kaddr);
But not in U-boot code, thus we have some reports of U-boot failed to
read compressed files in btrfs.
Fix it by doing the same thing of the kernel, for both inline and
regular compressed extents.
Reported-by: Matwey Kornilov <matwey.kornilov@gmail.com>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1183717
Fixes: a26a6bedaf ("fs: btrfs: Introduce btrfs_read_extent_inline() and btrfs_read_extent_reg()")
Signed-off-by: Qu Wenruo <wqu@suse.com>
When the btrfs_read_fs_root() function is searching a ROOT_ITEM with
location key offset other than -1, it currently fails via BUG_ON.
The offset can have other value than -1, though. This can happen for
example if a subvolume is renamed:
$ btrfs subvolume create X && sync
Create subvolume './X'
$ btrfs inspect-internal dump-tree /dev/root | grep -B 2 'name: X$
location key (270 ROOT_ITEM 18446744073709551615) type DIR
transid 283 data_len 0 name_len 1
name: X
$ mv X Y && sync
$ btrfs inspect-internal dump-tree /dev/root | grep -B 2 'name: Y$
location key (270 ROOT_ITEM 0) type DIR
transid 285 data_len 0 name_len 1
name: Y
As can be seen the offset changed from -1ULL to 0.
Do not fail in this case.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: David Sterba <dsterba@suse.com>
Cc: Qu Wenruo <wqu@suse.com>
Cc: Tom Rini <trini@konsulko.com>
Since commit 325dd1f642 ("fs: btrfs: Use btrfs_iter_dir() to ...")
when btrfs is listing a directory, the output is not aligned:
<SYMLINK> 15 Wed Sep 09 13:20:03 2020 boot.scr -> @/boot/boot.scr
<DIR> 0 Tue Feb 02 12:42:09 2021 @
<FILE> 108 Tue Feb 02 12:54:04 2021 1.info
Return back to how it was displayed previously, i.e.:
<SYM> 15 Wed Sep 09 13:20:03 2020 boot.scr -> @/boot/boot.scr
<DIR> 0 Tue Feb 02 12:42:09 2021 @
< > 108 Tue Feb 02 12:54:04 2021 1.info
Instead of '<FILE>', print '< >', as ext4 driver.
If an unknown directory item type is encountered, we will print the type
number left padded with spaces, enclosed by '?', instead of '<' and '>',
i.e.:
? 30? ............................. name
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Fixes: 325dd1f642 ("fs: btrfs: Use btrfs_iter_dir() to replace ...")
Cc: David Sterba <dsterba@suse.com>
Cc: Qu Wenruo <wqu@suse.com>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Skip xattrs in directory listing. U-Boot filesystem drivers do not list
xattrs.
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: David Sterba <dsterba@suse.com>
Cc: Qu Wenruo <wqu@suse.com>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Since commit 565a4147d1 ("fs: btrfs: Add more checksum algorithms")
btrfs uses the sha256 checksum algorithm. But Kconfig lacks to select
it. This leads to compilation errors:
fs/built-in.o: In function `hash_sha256':
fs/btrfs/crypto/hash.c:25: undefined reference to `sha256_starts'
fs/btrfs/crypto/hash.c:26: undefined reference to `sha256_update'
fs/btrfs/crypto/hash.c:27: undefined reference to `sha256_finish'
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
At the beginning of close_ctree_fs_info() the value 0 is assigned to err
and never changed before testing it.
Let's get rid of the superfluous variable.
Fixes: f06bfcf54d ("fs: btrfs: Crossport open_ctree_fs_info() from btrfs-progs")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
In __btrfs_map_block() we do a int * int and assign it to u64.
This is not safe as the result (int * int) is still evaluated as (int)
thus it can overflow.
Convert one of the multiplier to u64 to prevent such problem.
In real world, this should not cause problem as we have device number
limit thus it won't go beyond 4G for a single stripe.
But it's harder to teach coverity about all these hidden limits, so just
fix the possible overflow.
Reported-by: Coverity CID 312957
Reported-by: Coverity CID 312948
Signed-off-by: Qu Wenruo <wqu@suse.com>
In show_dir() if we hit a ROOT_ITEM, we can exit with uninitialized
@ret.
Fix it by initializing it to 0.
Reported-by: Coverity CID 312955
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
In btrfs_lookup_path() the local variable @type should always be updated
after we hit any file/dir.
But if @filename is NULL from the very beginning, then we don't
initialize it and return it directly.
To prevent such problem from happening, we initialize @type to
BTRFS_FT_UNKNOWN.
For normal execution route, it will get updated for each filename we
resolved.
Buf if we didn't find any path, we check if the type is still FT_UNKNOWN
and ret == 0. If true we know there is something wrong, just return
-EUCLEAN to inform the caller.
Reported-by: Coverity CID 312958
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This cleans up the now unneeded code from the old btrfs implementation.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This patch introduces a new function, list_one_subvol(), which will
resolve the path to FS_TREE of one subvolume.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This patch introduces a new function, get_path_in_subvolume(), which
resolves inode number into path inside a subvolume.
This function will be later used for btrfs subvolume list functionality.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This version of btrfs_file_read() has the following new features:
- Tries all mirrors
- More handling on unaligned size
- Better compressed extent handling
The old implementation doesn't handle compressed extent with offset
properly: we need to read out the whole compressed extent, then
decompress the whole extent, and only then copy the requested part.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This implements lookup_data_extent() function for the incoming
new implementation of btrfs_file_read().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
These two functions are used to do sector aligned read, which will be
later used to implement btrfs_file_read().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Rename btrfs_file_read() and its callees to avoid name conflicts with
the incoming new code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
After this the only remaining function that still utilizes
__btrfs_lookup_path() is btrfs_read().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Use extent buffer based infrastructure to re-implement btrfs_readdir().
Along this rework, some small corner cases fixed:
- Subvolume tree mtime
Mtime of a subvolume tree is recorded in its root item, since there is
no INODE_ITEM for it.
This needs extra search from tree root.
- Output the unknown type
If the DIR_ITEM is corrupted, at least don't try to access the memory
out of boundary.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This is the extent buffer based path lookup routine.
To implement this, btrfs_lookup_dir_item() is crossported from
btrfs-progs, and implements btrfs_lookup_path() from scratch.
Unlike the existing __btrfs_lookup_path(), since btrfs_read_fs_root()
will check whether a root is a orphan at read time, there is no need to
check root backref, this makes the code a little easier to read.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
All existing next_length() caller handles return value > BTRFS_NAME_LEN,
so there is no need to do BTRFS_NAME_LEN check in next_length().
But still, we want to exit early if we're beyond BTRFS_NAME_LEN, so this
patch makes next_length() exit as soon as we're beyond BTRFS_NAME_LEN.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
The existing __btrfs_readlink() can be easily re-implemented using the
extent buffer based btrfs_readlink().
This is the first step to re-implement U-Boot's btrfs code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Since the old code is using __btrfs_path/__btrfs_root which is different
from the regular extent buffer based one, we add "__" prefix for the old
implementation to avoid name conflicts for the incoming crossport.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
open_ctree_fs_info() is the main entry point to open btrfs.
This version is a simplfied version of __open_ctree_fd() of btrfs-progs,
the main differences are:
- Parameters on how to specify a block device
Instead of @fd and @path, U-Boot uses blk_desc and disk_partition_t.
- Remove open_ctree flags
There won't be multiple open ctree modes in U-Boot.
Otherwise functions structures are all kept the same.
With open_ctree_fs_info() implemented, also introduce the global
current_fs_info pointer to show the current opened btrfs.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
These two functions play a big role in btrfs bootstrap.
The following function is removed:
- Seed device support
Although in theory we can still support multiple devices, we don't have
a facility in U-Boot to do device scan without opening them.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This patch copies the core function, btrfs_search_slot(), from
btrfs-progs.
This version has the following functionality removed:
- The ability to COW tree block
Related code is commented out, and can be enabled in the future.
- The readahead functionality
This is abused in kernel. Remove it completely.
With the core function in place, btrfs developers should feel at home now.
This also crossports supporting code like btrfs_previous_item() to
ctree.[ch].
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Crossport struct btrfs_root to ctree.h from btrfs-progs, with write
related members deleted.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This is to avoid naming conflicts between extent buffer based
btrfs_root.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
To avoid name conflicting between the extent buffer based btrfs_path
from btrfs-progs, rename struct btrfs_path to struct __btrfs_path.
Also rename btrfs_free_path() to __btrfs_free_path() to avoid conflicts.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This is the one of the basic stone function for btrfs, which:
- Resolves the chunk mappings
- Reads data from disk
- Does various sanity check
With read_tree_block(), we can finally crossport needed btrfs btree
operations to U-Boot.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This patch crossports volumes.[ch] from btrfs-progs, including:
- btrfs_map_block()
The core mechanism to map btrfs logical address to physical address.
This version includes multi-device support, along with RAID56 support.
- btrfs_scan_one_device()
This is the function to register one btrfs device to the list.
This is the main part of the multi-device btrfs assembling process.
Although we're not going to support multiple devices until U-Boot
allows us to scan one device without actually opening it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
[trini: Use %zu in a debug print to avoid warning]
Signed-off-by: Tom Rini <trini@konsulko.com>
This brings all structure accessors from btrfs-progs/ctree.h, as in
kernel's ctree.h.
All these accessors handle the endian convert at runtime, and since all
of them are defined as static inline functions, those which aren't used
won't take space in resulting binary.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
This brings the extent_io_tree infrastructure, with which we can finally
bring in proper btrfs_fs_info structure to ctree.h.
With read/write_extent_buffer() implemented we also backport
read/write_eb_member() to ctree.h.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
