Commit Graph

1130 Commits

Author SHA1 Message Date
Linus Torvalds b2fe5fa686 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Significantly shrink the core networking routing structures. Result
    of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf

 2) Add netdevsim driver for testing various offloads, from Jakub
    Kicinski.

 3) Support cross-chip FDB operations in DSA, from Vivien Didelot.

 4) Add a 2nd listener hash table for TCP, similar to what was done for
    UDP. From Martin KaFai Lau.

 5) Add eBPF based queue selection to tun, from Jason Wang.

 6) Lockless qdisc support, from John Fastabend.

 7) SCTP stream interleave support, from Xin Long.

 8) Smoother TCP receive autotuning, from Eric Dumazet.

 9) Lots of erspan tunneling enhancements, from William Tu.

10) Add true function call support to BPF, from Alexei Starovoitov.

11) Add explicit support for GRO HW offloading, from Michael Chan.

12) Support extack generation in more netlink subsystems. From Alexander
    Aring, Quentin Monnet, and Jakub Kicinski.

13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From
    Russell King.

14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso.

15) Many improvements and simplifications to the NFP driver bpf JIT,
    from Jakub Kicinski.

16) Support for ipv6 non-equal cost multipath routing, from Ido
    Schimmel.

17) Add resource abstration to devlink, from Arkadi Sharshevsky.

18) Packet scheduler classifier shared filter block support, from Jiri
    Pirko.

19) Avoid locking in act_csum, from Davide Caratti.

20) devinet_ioctl() simplifications from Al viro.

21) More TCP bpf improvements from Lawrence Brakmo.

22) Add support for onlink ipv6 route flag, similar to ipv4, from David
    Ahern.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits)
  tls: Add support for encryption using async offload accelerator
  ip6mr: fix stale iterator
  net/sched: kconfig: Remove blank help texts
  openvswitch: meter: Use 64-bit arithmetic instead of 32-bit
  tcp_nv: fix potential integer overflow in tcpnv_acked
  r8169: fix RTL8168EP take too long to complete driver initialization.
  qmi_wwan: Add support for Quectel EP06
  rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK
  ipmr: Fix ptrdiff_t print formatting
  ibmvnic: Wait for device response when changing MAC
  qlcnic: fix deadlock bug
  tcp: release sk_frag.page in tcp_disconnect
  ipv4: Get the address of interface correctly.
  net_sched: gen_estimator: fix lockdep splat
  net: macb: Handle HRESP error
  net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring
  ipv6: addrconf: break critical section in addrconf_verify_rtnl()
  ipv6: change route cache aging logic
  i40e/i40evf: Update DESC_NEEDED value to reflect larger value
  bnxt_en: cleanup DIM work on device shutdown
  ...
2018-01-31 14:31:10 -08:00
Anand Jain 6f794e3c5c btrfs: fail mount when sb flag is not in BTRFS_SUPER_FLAG_SUPP
It appears from the original commit [1] that there isn't any design
specific reason not to fail the mount instead of just warning. This
patch will change it to fail.

[1]
 commit 319e4d0661
    btrfs: Enhance super validation check

Fixes: 319e4d0661 ("btrfs: Enhance super validation check")
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Anand Jain e2731e5588 btrfs: define SUPER_FLAG_METADUMP_V2
btrfs-progs uses super flag bit BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34).
So just define that in kernel so that we know its been used.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:21 +01:00
Anand Jain 6528b99d3d btrfs: factor btrfs_check_rw_degradable() to check given device
Update btrfs_check_rw_degradable() to check against the given device if
its lost.

We can use this function to know if the volume is going to be in
degraded mode OR failed state, when the given device fails.  Which is
needed when we are handling the device failed state.

A preparatory patch does not affect the flow as such.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ enhance comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:20 +01:00
David Sterba e43bbe5e16 btrfs: sink unlock_extent parameter gfp_flags
All callers pass either GFP_NOFS or GFP_KERNEL now, so we can sink the
parameter to the function, though we lose some of the slightly better
semantics of GFP_KERNEL in some places, it's worth cleaning up the
callchains.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:19 +01:00
Anand Jain 1c3063b6db btrfs: cleanup device states define BTRFS_DEV_STATE_FLUSH_SENT
Currently device state is being managed by each individual int
variable such as struct btrfs_device::is_tgtdev_for_dev_replace.
Instead of that declare btrfs_device::dev_state
BTRFS_DEV_STATE_FLUSH_SENT and use the bit operations.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:15 +01:00
Anand Jain e6e674bd4d btrfs: cleanup device states define BTRFS_DEV_STATE_MISSING
Currently device state is being managed by each individual int
variable such as struct btrfs_device::missing. Instead of that
declare btrfs_device::dev_state BTRFS_DEV_STATE_MISSING and use
the bit operations.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by : Nikolay Borisov <nborisov@suse.com>
[ whitespace adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:15 +01:00
Anand Jain e12c96214d btrfs: cleanup device states define BTRFS_DEV_STATE_IN_FS_METADATA
Currently device state is being managed by each individual int
variable such as struct btrfs_device::in_fs_metadata. Instead of
that declare device state BTRFS_DEV_STATE_IN_FS_METADATA and use
the bit operations.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
[ whitespace adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:15 +01:00
Anand Jain ebbede42d4 btrfs: cleanup device states define BTRFS_DEV_STATE_WRITEABLE
Currently device state is being managed by each individual int
variable such as struct btrfs_device::writeable. Instead of that
declare device state BTRFS_DEV_STATE_WRITEABLE and use the
bit operations.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ whitespace adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:15 +01:00
David Sterba 71a635516c btrfs: switch to on-stack csum buffer in csum_tree_block
The maximum size of a checksum buffer is known, BTRFS_CSUM_SIZE, and we
don't have to allocate it dynamically. This code path is not used at all
as we have only the crc32c and use an on-stack buffer already.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:14 +01:00
David Sterba 6af49dbde9 btrfs: sink get_extent parameter to read_extent_buffer_pages
All callers pass btree_get_extent, which needs to be exported.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:13 +01:00
David Sterba 1538e6c52e btrfs: use non-RCU list traversal in write_all_supers callees
We take the fs_devices::device_list_mutex mutex in write_all_supers
which will prevent any add/del changes to the device list. Therefore we
don't need to use the RCU variant list_for_each_entry_rcu in any of the
called functions.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:12 +01:00
Qu Wenruo 33d85fda13 btrfs: Don't generate UUID for non-fs tree
btrfs_create_tree() will unconditionally generate UUID for any root.
So for quota tree and data reloc tree created by kernel, they will have
unique UUIDs.

However UUID in root item is only referred by UUID tree, which only
records UUID for fs trees.  This makes unique UUIDs for quota/data reloc
tree meaningless.

Leave the UUID as zero for non-fs tree, making btrfs-debug-tree output
less confusing.

Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:11 +01:00
Masami Hiramatsu 663faf9f7b error-injection: Add injectable error types
Add injectable error types for each error-injectable function.

One motivation of error injection test is to find software flaws,
mistakes or mis-handlings of expectable errors. If we find such
flaws by the test, that is a program bug, so we need to fix it.

But if the tester miss input the error (e.g. just return success
code without processing anything), it causes unexpected behavior
even if the caller is correctly programmed to handle any errors.
That is not what we want to test by error injection.

To clarify what type of errors the caller must expect for each
injectable function, this introduces injectable error types:

 - EI_ETYPE_NULL : means the function will return NULL if it
		    fails. No ERR_PTR, just a NULL.
 - EI_ETYPE_ERRNO : means the function will return -ERRNO
		    if it fails.
 - EI_ETYPE_ERRNO_NULL : means the function will return -ERRNO
		       (ERR_PTR) or NULL.

ALLOW_ERROR_INJECTION() macro is expanded to get one of
NULL, ERRNO, ERRNO_NULL to record the error type for
each function. e.g.

 ALLOW_ERROR_INJECTION(open_ctree, ERRNO)

This error types are shown in debugfs as below.

  ====
  / # cat /sys/kernel/debug/error_injection/list
  open_ctree [btrfs]	ERRNO
  io_ctl_init [btrfs]	ERRNO
  ====

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-12 17:33:38 -08:00
Masami Hiramatsu 540adea380 error-injection: Separate error-injection from kprobe
Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.

Some differences has been made:

- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
  ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
  feature. It is automatically enabled if the arch supports
  error injection feature for kprobe or ftrace etc.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-12 17:33:38 -08:00
David S. Miller 59436c9ee1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2017-12-18

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Allow arbitrary function calls from one BPF function to another BPF function.
   As of today when writing BPF programs, __always_inline had to be used in
   the BPF C programs for all functions, unnecessarily causing LLVM to inflate
   code size. Handle this more naturally with support for BPF to BPF calls
   such that this __always_inline restriction can be overcome. As a result,
   it allows for better optimized code and finally enables to introduce core
   BPF libraries in the future that can be reused out of different projects.
   x86 and arm64 JIT support was added as well, from Alexei.

2) Add infrastructure for tagging functions as error injectable and allow for
   BPF to return arbitrary error values when BPF is attached via kprobes on
   those. This way of injecting errors generically eases testing and debugging
   without having to recompile or restart the kernel. Tags for opting-in for
   this facility are added with BPF_ALLOW_ERROR_INJECTION(), from Josef.

3) For BPF offload via nfp JIT, add support for bpf_xdp_adjust_head() helper
   call for XDP programs. First part of this work adds handling of BPF
   capabilities included in the firmware, and the later patches add support
   to the nfp verifier part and JIT as well as some small optimizations,
   from Jakub.

4) The bpftool now also gets support for basic cgroup BPF operations such
   as attaching, detaching and listing current BPF programs. As a requirement
   for the attach part, bpftool can now also load object files through
   'bpftool prog load'. This reuses libbpf which we have in the kernel tree
   as well. bpftool-cgroup man page is added along with it, from Roman.

5) Back then commit e87c6bc385 ("bpf: permit multiple bpf attachments for
   a single perf event") added support for attaching multiple BPF programs
   to a single perf event. Given they are configured through perf's ioctl()
   interface, the interface has been extended with a PERF_EVENT_IOC_QUERY_BPF
   command in this work in order to return an array of one or multiple BPF
   prog ids that are currently attached, from Yonghong.

6) Various minor fixes and cleanups to the bpftool's Makefile as well
   as a new 'uninstall' and 'doc-uninstall' target for removing bpftool
   itself or prior installed documentation related to it, from Quentin.

7) Add CONFIG_CGROUP_BPF=y to the BPF kernel selftest config file which is
   required for the test_dev_cgroup test case to run, from Naresh.

8) Fix reporting of XDP prog_flags for nfp driver, from Jakub.

9) Fix libbpf's exit code from the Makefile when libelf was not found in
   the system, also from Jakub.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-18 10:51:06 -05:00
Josef Bacik 8556e50994 btrfs: make open_ctree error injectable
This allows us to do error injection with BPF for open_ctree.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12 08:56:26 -08:00
Omar Sandoval 1b9e619c5b Btrfs: disable FUA if mounted with nobarrier
I was seeing disk flushes still happening when I mounted a Btrfs
filesystem with nobarrier for testing. This is because we use FUA to
write out the first super block, and on devices without FUA support, the
block layer translates FUA to a flush. Even on devices supporting true
FUA, using FUA when we asked for no barriers is surprising.

Fixes: 387125fc72 ("Btrfs: fix barrier flushes")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-07 00:34:45 +01:00
Qu Wenruo 69fc6cbbac btrfs: tree-checker: Fix false panic for sanity test
[BUG]
If we run btrfs with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y, it will
instantly cause kernel panic like:

------
...
assertion failed: 0, file: fs/btrfs/disk-io.c, line: 3853
...
Call Trace:
 btrfs_mark_buffer_dirty+0x187/0x1f0 [btrfs]
 setup_items_for_insert+0x385/0x650 [btrfs]
 __btrfs_drop_extents+0x129a/0x1870 [btrfs]
...
-----

[Cause]
Btrfs will call btrfs_check_leaf() in btrfs_mark_buffer_dirty() to check
if the leaf is valid with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y.

However quite some btrfs_mark_buffer_dirty() callers(*) don't really
initialize its item data but only initialize its item pointers, leaving
item data uninitialized.

This makes tree-checker catch uninitialized data as error, causing
such panic.

*: These callers include but not limited to
setup_items_for_insert()
btrfs_split_item()
btrfs_expand_item()

[Fix]
Add a new parameter @check_item_data to btrfs_check_leaf().
With @check_item_data set to false, item data check will be skipped and
fallback to old btrfs_check_leaf() behavior.

So we can still get early warning if we screw up item pointers, and
avoid false panic.

Cc: Filipe Manana <fdmanana@gmail.com>
Reported-by: Lakshmipathi.G <lakshmipathi.g@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-28 14:59:09 +01:00
Josef Bacik 0e0adbcfdc btrfs: track refs in a rb_tree instead of a list
If we get a significant amount of delayed refs for a single block (think
modifying multiple snapshots) we can end up spending an ungodly amount
of time looping through all of the entries trying to see if they can be
merged.  This is because we only add them to a list, so we have O(2n)
for every ref head.  This doesn't make any sense as we likely have refs
for different roots, and so they cannot be merged.  Tracking in a tree
will allow us to break as soon as we hit an entry that doesn't match,
making our worst case O(n).

With this we can also merge entries more easily.  Before we had to hope
that matching refs were on the ends of our list, but with the tree we
can search down to exact matches and merge them at insert time.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Josef Bacik 69fe2d75dd btrfs: make the delalloc block rsv per inode
The way we handle delalloc metadata reservations has gotten
progressively more complicated over the years.  There is so much cruft
and weirdness around keeping the reserved count and outstanding counters
consistent and handling the error cases that it's impossible to
understand.

Fix this by making the delalloc block rsv per-inode.  This way we can
calculate the actual size of the outstanding metadata reservations every
time we make a change, and then reserve the delta based on that amount.
This greatly simplifies the code everywhere, and makes the error
handling in btrfs_delalloc_reserve_metadata far less terrifying.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Nikolay Borisov d4417e2255 btrfs: Replace opencoded sizes with their symbolic constants
Currently btrfs' code uses a mix of opencoded sizes and defines from sizes.h.
Let's unifiy the code base to always use the symbolic constants. No functional
changes

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Josef Bacik d278850eff btrfs: remove delayed_ref_node from ref_head
This is just excessive information in the ref_head, and makes the code
complicated.  It is a relic from when we had the heads and the refs in
the same tree, which is no longer the case.  With this removal I've
cleaned up a bunch of the cruft around this old assumption as well.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Josef Bacik fd708b81d9 Btrfs: add a extent ref verify tool
We were having corruption issues that were tied back to problems with
the extent tree.  In order to track them down I built this tool to try
and find the culprit, which was pretty successful.  If you compile with
this tool on it will live verify every ref update that the fs makes and
make sure it is consistent and valid.  I've run this through with
xfstests and haven't gotten any false positives.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update error messages, add fixup from Dan Carpenter to handle errors
  of read_tree_block ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Liu Bo 736cd52e0c Btrfs: remove nr_async_submits and async_submit_draining
Now that we have the combo of flushing twice, which can make sure IO
have started since the second flush will wait for page lock which
won't be unlocked unless setting page writeback and queuing ordered
extents, we don't need %async_submit_draining, %async_delalloc_pages
and %nr_async_submits to tell whether the IO has actually started.

Moreover, all the flushers in use are followed by functions that wait
for ordered extents to complete, so %nr_async_submits, which tracks
whether bio's async submit has made progress, doesn't really make
sense.

However, %async_delalloc_pages is still required by shrink_delalloc()
as that function doesn't flush twice in the normal case (just issues a
writeback with WB_REASON_FS_FREE_SPACE).

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:59 +01:00
Liu Bo f851689b5a Btrfs: remove nr_async_bios
This was intended to congest higher layers to not send bios, but as

1) the congested bit has been taken by writeback

Async bios come from buffered writes and DIO writes.

For DIO writes, we want to submit them ASAP, while for buffered writes,
writeback uses balance_dirty_pages() to throttle how much dirty pages we
can have.

2) and no one is waiting for %nr_async_bios down to zero,

Historically, it was introduced along with changes which let
checksumming workload spread accross different cpus.  And at that time,
pdflush was used instead of per-bdi flushing, perhaps pdflush did not
have the necessary information for writeback to do throttling.

We can safely remove them now.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
[ additional explanation from mails, removed unused variable 'limit' ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:59 +01:00
Qu Wenruo 557ea5dd00 btrfs: Move leaf and node validation checker to tree-checker.c
It's no doubt the comprehensive tree block checker will become larger,
so moving them into their own files is quite reasonable.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
[ wording adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:58 +01:00
Qu Wenruo 4b865cab96 btrfs: Add checker for EXTENT_CSUM
EXTENT_CSUM checker is a relatively easy one, only needs to check:

1) Objectid
   Fixed to BTRFS_EXTENT_CSUM_OBJECTID

2) Key offset alignment
   Must be aligned to sectorsize

3) Item size alignedment
   Must be aligned to csum size

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:58 +01:00
Qu Wenruo 40c3c40947 btrfs: Add sanity check for EXTENT_DATA when reading out leaf
Add extra checks for item with EXTENT_DATA type.  This checks the
following thing:

0) Key offset
   All key offsets must be aligned to sectorsize.
   Inline extent must have 0 for key offset.

1) Item size
   Uncompressed inline file extent size must match item size.
   (Compressed inline file extent has no information about its on-disk size.)
   Regular/preallocated file extent size must be a fixed value.

2) Every member of regular file extent item
   Including alignment for bytenr and offset, possible value for
   compression/encryption/type.

3) Type/compression/encode must be one of the valid values.

This should be the most comprehensive and strict check in the context
of btrfs_item for EXTENT_DATA.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ switch to BTRFS_FILE_EXTENT_TYPES, similar to what
  BTRFS_COMPRESS_TYPES does ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:58 +01:00
Qu Wenruo 7f43d4affb btrfs: Check if item pointer overlaps with the item itself
Function check_leaf() checks if any item pointer points outside of the
leaf, but it doesn't check if the pointer overlaps with the item itself.

Normally only the last item may be the victim, but adding such check is
never a bad idea anyway.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:58 +01:00
Qu Wenruo c3267bbaa9 btrfs: Refactor check_leaf function for later expansion
Current check_leaf() function does a good job checking key order and
item offset/size.

However it only checks from slot 0 to the last but one slot, this is
good but makes later expansion hard.

So this refactoring iterates from slot 0 to the last slot.
For key comparison, it uses a key with all 0 as initial key, so all
valid keys should be larger than that.

And for item size/offset checks, it compares current item end with
previous item offset.
For slot 0, use leaf end as a special case.

This makes later item/key offset checks and item size checks easier to
be implemented.

Also, makes check_leaf() to return -EUCLEAN other than -EIO to indicate
error.

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:57 +01:00
Liu Bo 18fdc67900 Btrfs: remove bio_flags which indicates a meta block of log-tree
Since both committing transaction and writing log-tree are doing
plugging on metadata IO, we can unify to use %sync_writers to benefit
both cases, instead of checking bio_flags while writing meta blocks of
log-tree.

We can remove this bio_flags because in order to write dirty blocks,
log tree also uses btrfs_write_marked_extents(), inside which we
have enabled %sync_writers, therefore, every write goes in a
synchronous way, so does checksuming.

Please also note that, bio_flags is applied per-context while
%sync_writers is applied per-inode, so this might incur some overhead, ie.

1) while log tree is flushing its dirty blocks via
   btrfs_write_marked_extents(), in which %sync_writers is increased
   by one.

2) in the meantime, some writeback operations may happen upon btrfs's
   metadata inode, so these writes go synchronously, too.

However, AFAICS, the overhead is not a big one while the win is that
we unify the two places that needs synchronous way and remove a
special hack/flag.

This removes the bio_flags related stuff for writing log-tree.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:56 +01:00
Liu Bo 6300463b14 Btrfs: make plug in writing meta blocks really work
We have started plug in btrfs_write_and_wait_marked_extents() but the
generated IOs actually go to device's schedule IO list where the work
is doing in another task, thus the started plug doesn't make any
sense.

And since we wait for IOs immediately after writing meta blocks, it's
the same case as writing log tree, doing sync submit can merge more
IOs.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:56 +01:00
Anand Jain ee87cf5ed9 btrfs: copy fsid to super_block s_uuid
We didn't copy fsid to struct super_block.s_uuid so Overlay disables
index feature with btrfs as the lower FS.

kernel: overlayfs: fs on '/lower' does not support file handles, falling back to index=off.

Fix this by publishing the fsid through struct super_block.s_uuid.

[ dsterba: I think that setting s_uuid is the last missing bit. Overlay
  needs the file handle encoding support from the lower filesystem, which
  is supported. Filling the whole filesystem id is correct, the subvolume
  id is encoded in the file handle buffer from inside btrfs_encode_fh. ]

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:55 +01:00
Linus Torvalds 5ba88cd6e9 Merge branch 'for-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
 "We've collected a bunch of isolated fixes, for crashes, user-visible
  behaviour or missing bits from other subsystem cleanups from the past.

  The overall number is not small but I was not able to make it
  significantly smaller. Most of the patches are supposed to go to
  stable"

* 'for-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: log csums for all modified extents
  Btrfs: fix unexpected result when dio reading corrupted blocks
  btrfs: Report error on removing qgroup if del_qgroup_item fails
  Btrfs: skip checksum when reading compressed data if some IO have failed
  Btrfs: fix kernel oops while reading compressed data
  Btrfs: use btrfs_op instead of bio_op in __btrfs_map_block
  Btrfs: do not backup tree roots when fsync
  btrfs: remove BTRFS_FS_QUOTA_DISABLING flag
  btrfs: propagate error to btrfs_cmp_data_prepare caller
  btrfs: prevent to set invalid default subvolid
  Btrfs: send: fix error number for unknown inode types
  btrfs: fix NULL pointer dereference from free_reloc_roots()
  btrfs: finish ordered extent cleaning if no progress is found
  btrfs: clear ordered flag on cleaning up ordered extents
  Btrfs: fix incorrect {node,sector}size endianness from BTRFS_IOC_FS_INFO
  Btrfs: do not reset bio->bi_ops while writing bio
  Btrfs: use the new helper wbc_to_write_flags
2017-09-29 12:57:35 -07:00
Liu Bo fed3b38114 Btrfs: do not backup tree roots when fsync
It doesn't make sense to backup tree roots when doing fsync, since
during fsync those tree roots have not been consistent on disk.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-26 14:53:04 +02:00
Linus Torvalds 0f0d12728e Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull mount flag updates from Al Viro:
 "Another chunk of fmount preparations from dhowells; only trivial
  conflicts for that part. It separates MS_... bits (very grotty
  mount(2) ABI) from the struct super_block ->s_flags (kernel-internal,
  only a small subset of MS_... stuff).

  This does *not* convert the filesystems to new constants; only the
  infrastructure is done here. The next step in that series is where the
  conflicts would be; that's the conversion of filesystems. It's purely
  mechanical and it's better done after the merge, so if you could run
  something like

	list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$')

	sed -i -e 's/\<MS_RDONLY\>/SB_RDONLY/g' \
	        -e 's/\<MS_NOSUID\>/SB_NOSUID/g' \
	        -e 's/\<MS_NODEV\>/SB_NODEV/g' \
	        -e 's/\<MS_NOEXEC\>/SB_NOEXEC/g' \
	        -e 's/\<MS_SYNCHRONOUS\>/SB_SYNCHRONOUS/g' \
	        -e 's/\<MS_MANDLOCK\>/SB_MANDLOCK/g' \
	        -e 's/\<MS_DIRSYNC\>/SB_DIRSYNC/g' \
	        -e 's/\<MS_NOATIME\>/SB_NOATIME/g' \
	        -e 's/\<MS_NODIRATIME\>/SB_NODIRATIME/g' \
	        -e 's/\<MS_SILENT\>/SB_SILENT/g' \
	        -e 's/\<MS_POSIXACL\>/SB_POSIXACL/g' \
	        -e 's/\<MS_KERNMOUNT\>/SB_KERNMOUNT/g' \
	        -e 's/\<MS_I_VERSION\>/SB_I_VERSION/g' \
	        -e 's/\<MS_LAZYTIME\>/SB_LAZYTIME/g' \
	        $list

  and commit it with something along the lines of 'convert filesystems
  away from use of MS_... constants' as commit message, it would save a
  quite a bit of headache next cycle"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  VFS: Differentiate mount flags (MS_*) from internal superblock flags
  VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)
  vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags
2017-09-14 18:54:01 -07:00
Linus Torvalds e7cdb60fd2 Merge branch 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull zstd support from Chris Mason:
 "Nick Terrell's patch series to add zstd support to the kernel has been
  floating around for a while. After talking with Dave Sterba, Herbert
  and Phillip, we decided to send the whole thing in as one pull
  request.

  zstd is a big win in speed over zlib and in compression ratio over
  lzo, and the compression team here at FB has gotten great results
  using it in production. Nick will continue to update the kernel side
  with new improvements from the open source zstd userland code.

  Nick has a number of benchmarks for the main zstd code in his lib/zstd
  commit:

      I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB
      of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel
      Core i7 processor, 16 GB of RAM, and a SSD. I benchmarked using
      `silesia.tar` [3], which is 211,988,480 B large. Run the following
      commands for the benchmark:

        sudo modprobe zstd_compress_test
        sudo mknod zstd_compress_test c 245 0
        sudo cp silesia.tar zstd_compress_test

      The time is reported by the time of the userland `cp`.
      The MB/s is computed with

        1,536,217,008 B / time(buffer size, hash)

      which includes the time to copy from userland.
      The Adjusted MB/s is computed with

        1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).

      The memory reported is the amount of memory the compressor
      requests.

        | Method   | Size (B) | Time (s) | Ratio | MB/s    | Adj MB/s | Mem (MB) |
        |----------|----------|----------|-------|---------|----------|----------|
        | none     | 11988480 |    0.100 |     1 | 2119.88 |        - |        - |
        | zstd -1  | 73645762 |    1.044 | 2.878 |  203.05 |   224.56 |     1.23 |
        | zstd -3  | 66988878 |    1.761 | 3.165 |  120.38 |   127.63 |     2.47 |
        | zstd -5  | 65001259 |    2.563 | 3.261 |   82.71 |    86.07 |     2.86 |
        | zstd -10 | 60165346 |   13.242 | 3.523 |   16.01 |    16.13 |    13.22 |
        | zstd -15 | 58009756 |   47.601 | 3.654 |    4.45 |     4.46 |    21.61 |
        | zstd -19 | 54014593 |  102.835 | 3.925 |    2.06 |     2.06 |    60.15 |
        | zlib -1  | 77260026 |    2.895 | 2.744 |   73.23 |    75.85 |     0.27 |
        | zlib -3  | 72972206 |    4.116 | 2.905 |   51.50 |    52.79 |     0.27 |
        | zlib -6  | 68190360 |    9.633 | 3.109 |   22.01 |    22.24 |     0.27 |
        | zlib -9  | 67613382 |   22.554 | 3.135 |    9.40 |     9.44 |     0.27 |

      I benchmarked zstd decompression using the same method on the same
      machine. The benchmark file is located in the upstream zstd repo
      under `contrib/linux-kernel/zstd_decompress_test.c` [4]. The
      memory reported is the amount of memory required to decompress
      data compressed with the given compression level. If you know the
      maximum size of your input, you can reduce the memory usage of
      decompression irrespective of the compression level.

        | Method   | Time (s) | MB/s    | Adjusted MB/s | Memory (MB) |
        |----------|----------|---------|---------------|-------------|
        | none     |    0.025 | 8479.54 |             - |           - |
        | zstd -1  |    0.358 |  592.15 |        636.60 |        0.84 |
        | zstd -3  |    0.396 |  535.32 |        571.40 |        1.46 |
        | zstd -5  |    0.396 |  535.32 |        571.40 |        1.46 |
        | zstd -10 |    0.374 |  566.81 |        607.42 |        2.51 |
        | zstd -15 |    0.379 |  559.34 |        598.84 |        4.61 |
        | zstd -19 |    0.412 |  514.54 |        547.77 |        8.80 |
        | zlib -1  |    0.940 |  225.52 |        231.68 |        0.04 |
        | zlib -3  |    0.883 |  240.08 |        247.07 |        0.04 |
        | zlib -6  |    0.844 |  251.17 |        258.84 |        0.04 |
        | zlib -9  |    0.837 |  253.27 |        287.64 |        0.04 |

  I ran a long series of tests and benchmarks on the btrfs side and the
  gains are very similar to the core benchmarks Nick ran"

* 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  squashfs: Add zstd support
  btrfs: Add zstd support
  lib: Add zstd modules
  lib: Add xxhash module
2017-09-14 17:30:49 -07:00
Linus Torvalds 66ba772ee3 Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
 "The changes range through all types: cleanups, core chagnes, sanity
  checks, fixes, other user visible changes, detailed list below:

   - deprecated: user transaction ioctl

   - mount option ssd does not change allocation alignments

   - degraded read-write mount is allowed if all the raid profile
     constraints are met, now based on more accurate check

   - defrag: do not reset compression afterwards; the NOCOMPRESS flag
     can be now overriden by defrag

   - prep work for better extent reference tracking (related to the
     qgroup slowness with balance)

   - prep work for compression heuristics

   - memory allocation reductions (may help latencies on a loaded
     system)

   - better accounting for io waiting states

   - error handling improvements (removed BUGs)

   - added more sanity checks for shared refs

   - fix readdir vs pagefault deadlock under some circumstances

   - fix for 'no-hole' mode, certain combination of compressed and
     inline extents

   - send: fix emission of invalid clone operations

   - fixup file mode if setting acls fail

   - more fixes from fuzzing

   - oher cleanups"

* 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (104 commits)
  btrfs: submit superblock io with REQ_META and REQ_PRIO
  btrfs: remove unnecessary memory barrier in btrfs_direct_IO
  btrfs: remove superfluous chunk_tree argument from btrfs_alloc_dev_extent
  btrfs: Remove chunk_objectid parameter of btrfs_alloc_dev_extent
  btrfs: pass fs_info to btrfs_del_root instead of tree_root
  Btrfs: add one more sanity check for shared ref type
  Btrfs: remove BUG_ON in __add_tree_block
  Btrfs: remove BUG() in add_data_reference
  Btrfs: remove BUG() in print_extent_item
  Btrfs: remove BUG() in btrfs_extent_inline_ref_size
  Btrfs: convert to use btrfs_get_extent_inline_ref_type
  Btrfs: add a helper to retrive extent inline ref type
  btrfs: scrub: simplify scrub worker initialization
  btrfs: scrub: clean up division in scrub_find_csum
  btrfs: scrub: clean up division in __scrub_mark_bitmap
  btrfs: scrub: use bool for flush_all_writes
  btrfs: preserve i_mode if __btrfs_set_acl() fails
  btrfs: Remove extraneous chunk_objectid variable
  btrfs: Remove chunk_objectid argument from btrfs_make_block_group
  btrfs: Remove extra parentheses from condition in copy_items()
  ...
2017-09-09 13:27:51 -07:00
Linus Torvalds a0725ab0c7 Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...
2017-09-07 11:59:42 -07:00
Omar Sandoval 58efbc9f54 Btrfs: fix blk_status_t/errno confusion
This fixes several instances of blk_status_t and bare errno ints being
mixed up, some of which are real bugs.

In the normal case, 0 matches BLK_STS_OK, so we don't observe any
effects of the missing conversion, but in case of errors or passes
through the repair/retry paths, the errors get mixed up.

The changes were identified using 'sparse', we don't have reports of the
buggy behaviour.

Fixes: 4e4cbee93d ("block: switch bios to blk_status_t")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-24 17:19:02 +02:00
Christoph Hellwig 74d46992e0 block: replace bi_bdev with a gendisk pointer and partitions index
This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 12:49:55 -06:00
David Sterba db95c876c5 btrfs: submit superblock io with REQ_META and REQ_PRIO
The superblock is also metadata of the filesystem so the relevant IO
should be tagged as such. We also tag it as high priority, as it's the
last block committed for metadata from a given transaction. Any delays
would effectively block the whole transaction, also blocking any other
operation holding the device_list_mutex.

Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-22 13:22:05 +02:00
Hans van Kranenburg 583b723151 btrfs: Do not use data_alloc_cluster in ssd mode
This patch provides a band aid to improve the 'out of the box'
behaviour of btrfs for disks that are detected as being an ssd.  In a
general purpose mixed workload scenario, the current ssd mode causes
overallocation of available raw disk space for data, while leaving
behind increasing amounts of unused fragmented free space. This
situation leads to early ENOSPC problems which are harming user
experience and adoption of btrfs as a general purpose filesystem.

This patch modifies the data extent allocation behaviour of the ssd mode
to make it behave identical to nossd mode.  The metadata behaviour and
additional ssd_spread option stay untouched so far.

Recommendations for future development are to reconsider the current
oversimplified nossd / ssd distinction and the broken detection
mechanism based on the rotational attribute in sysfs and provide
experienced users with a more flexible way to choose allocator behaviour
for data and metadata, optimized for certain use cases, while keeping
sane 'out of the box' default settings.  The internals of the current
btrfs code have more potential than what currently gets exposed to the
user to choose from.

    The SSD story...

    In the first year of btrfs development, around early 2008, btrfs
gained a mount option which enables specific functionality for
filesystems on solid state devices. The first occurance of this
functionality is in commit e18e4809, labeled "Add mount -o ssd, which
includes optimizations for seek free storage".

The effect on allocating free space for doing (data) writes is to
'cluster' writes together, writing them out in contiguous space, as
opposed to a 'tetris' way of putting all separate writes into any free
space fragment that fits (which is what the -o nossd behaviour does).

A somewhat simplified explanation of what happens is that, when for
example, the 'cluster' size is set to 2MiB, when we do some writes, the
data allocator will search for a free space block that is 2MiB big, and
put the writes in there. The ssd mode itself might allow a 2MiB cluster
to be composed of multiple free space extents with some existing data in
between, while the additional ssd_spread mount option kills off this
option and requires fully free space.

The idea behind this is (commit 536ac8ae): "The [...] clusters make it
more likely a given IO will completely overwrite the ssd block, so it
doesn't have to do an internal rwm cycle."; ssd block meaning nand erase
block. So, effectively this means applying a "locality based algorithm"
and trying to outsmart the actual ssd.

Since then, various changes have been made to the involved code, but the
basic idea is still present, and gets activated whenever the ssd mount
option is active. This also happens by default, when the rotational flag
as seen at /sys/block/<device>/queue/rotational is set to 0.

    However, there's a number of problems with this approach.

    First, what the optimization is trying to do is outsmart the ssd by
assuming there is a relation between the physical address space of the
block device as seen by btrfs and the actual physical storage of the
ssd, and then adjusting data placement. However, since the introduction
of the Flash Translation Layer (FTL) which is a part of the internal
controller of an ssd, these attempts are futile. The use of good quality
FTL in consumer ssd products might have been limited in 2008, but this
situation has changed drastically soon after that time. Today, even the
flash memory in your automatic cat feeding machine or your grandma's
wheelchair has a full featured one.

Second, the behaviour as described above results in the filesystem being
filled up with badly fragmented free space extents because of relatively
small pieces of space that are freed up by deletes, but not selected
again as part of a 'cluster'. Since the algorithm prefers allocating a
new chunk over going back to tetris mode, the end result is a filesystem
in which all raw space is allocated, but which is composed of
underutilized chunks with a 'shotgun blast' pattern of fragmented free
space. Usually, the next problematic thing that happens is the
filesystem wanting to allocate new space for metadata, which causes the
filesystem to fail in spectacular ways.

Third, the default mount options you get for an ssd ('ssd' mode enabled,
'discard' not enabled), in combination with spreading out writes over
the full address space and ignoring freed up space leads to worst case
behaviour in providing information to the ssd itself, since it will
never learn that all the free space left behind is actually free.  There
are two ways to let an ssd know previously written data does not have to
be preserved, which are sending explicit signals using discard or
fstrim, or by simply overwriting the space with new data.  The worst
case behaviour is the btrfs ssd_spread mount option in combination with
not having discard enabled. It has a side effect of minimizing the reuse
of free space previously written in.

Fourth, the rotational flag in /sys/ does not reliably indicate if the
device is a locally attached ssd. For example, iSCSI or NBD displays as
non-rotational, while a loop device on an ssd shows up as rotational.

The combination of the second and third problem effectively means that
despite all the good intentions, the btrfs ssd mode reliably causes the
ssd hardware and the filesystem structures and performance to be choked
to death. The clickbait version of the title of this story would have
been "Btrfs ssd optimizations considered harmful for ssds".

The current nossd 'tetris' mode (even still without discard) allows a
pattern of overwriting much more previously used space, causing many
more implicit discards to happen because of the overwrite information
the ssd gets. The actual location in the physical address space, as seen
from the point of view of btrfs is irrelevant, because the actual writes
to the low level flash are reordered anyway thanks to the FTL.

    Changes made in the code

1. Make ssd mode data allocation identical to tetris mode, like nossd.
2. Adjust and clean up filesystem mount messages so that we can easily
identify if a kernel has this patch applied or not, when providing
support to end users. Also, make better use of the *_and_info helpers to
only trigger messages on actual state changes.

    Backporting notes

Notes for whoever wants to backport this patch to their 4.9 LTS kernel:
* First apply commit 951e7966 "btrfs: drop the nossd flag when
  remounting with -o ssd", or fixup the differences manually.
* The rest of the conflicts are because of the fs_info refactoring. So,
  for example, instead of using fs_info, it's root->fs_info in
  extent-tree.c

Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-21 17:47:42 +02:00
Lu Fengqi 43a0111103 btrfs: use btrfsic_submit_bio instead of submit_bio in write_dev_flush
Although this bio has no data attached, it will reach this condition
(bio->bi_opf & REQ_PREFLUSH) and then update the flush_gen of dev_state
in __btrfsic_submit_bio. So we should still submit it through integrity
checker. Otherwise, the integrity checker will throw the following warning
when I mount a newly created btrfs filesystem.

[10264.755497] btrfs: attempt to write superblock which references block M @29523968 (sdb1/1111654400/0) which is not flushed out of disk's write cache (block flush_gen=1, dev->flush_gen=0)!
[10264.755498] btrfs: attempt to write superblock which references block M @29523968 (sdb1/37912576/0) which is not flushed out of disk's write cache (block flush_gen=1, dev->flush_gen=0)!

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-21 17:47:42 +02:00
Anand Jain 44880fdc91 btrfs: use appropriate define for the fsid
Though BTRFS_FSID_SIZE and BTRFS_UUID_SIZE are of the same size, we
should use the matching constant for the fsid buffer.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-18 16:36:29 +02:00
David Sterba 4958aa6821 btrfs: drop chunk locks at the end of close_ctree
The pinned chunks might be left over so we clean them but at this point
of close_ctree, there's noone to race with, the locking can be removed.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:04 +02:00
David Sterba ea14b57fd1 btrfs: fix spelling of snapshotting
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:04 +02:00
David Sterba 9f6d251033 btrfs: use named constant for bdev blocksize
Superblock is read and written using buffer heads, we need to set the
bdev blocksize. The magic constant has been hardcoded in several places,
so replace it with a named constant.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:04 +02:00
David Sterba abbb3b8ebf btrfs: split write_dev_supers to two functions
There are two independent parts, one that writes the superblocks and
another that waits for completion. No functional changes, but cleanups,
reformatting and comment updates.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:04 +02:00