Everytime we write out dirty pages we search for an offset in the tree,
convert the bits in the state, and then when we wait we search for the
offset again and clear the bits. So for every dirty range in the io tree we
are doing 4 rb searches, which is suboptimal. With this patch we are only
doing 2 searches for every cycle (modulo weird things happening). Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Using for_each_set_bit_from() to simplify the code.
spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
If a block group is ro, do not count its entries in when we dump space info.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull btrfs updates from Chris Mason:
"I held off on my rc5 pull because I hit an oops during log recovery
after a crash. I wanted to make sure it wasn't a regression because
we have some logging fixes in here.
It turns out that a commit during the merge window just made it much
more likely to trigger directory logging instead of full commits,
which exposed an old bug.
The new backref walking code got some additional fixes. This should
be the final set of them.
Josef fixed up a corner where our O_DIRECT writes and buffered reads
could expose old file contents (not stale, just not the most recent).
He and Liu Bo fixed crashes during tree log recover as well.
Ilya fixed errors while we resume disk balancing operations on
readonly mounts."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: run delayed directory updates during log replay
Btrfs: hold a ref on the inode during writepages
Btrfs: fix tree log remove space corner case
Btrfs: fix wrong check during log recovery
Btrfs: use _IOR for BTRFS_IOC_SUBVOL_GETFLAGS
Btrfs: resume balance on rw (re)mounts properly
Btrfs: restore restriper state on all mounts
Btrfs: fix dio write vs buffered read race
Btrfs: don't count I/O statistic read errors for missing devices
Btrfs: resolve tree mod log locking issue in btrfs_next_leaf
Btrfs: fix tree mod log rewind of ADD operations
Btrfs: leave critical region in btrfs_find_all_roots as soon as possible
Btrfs: always put insert_ptr modifications into the tree mod log
Btrfs: fix tree mod log for root replacements at leaf level
Btrfs: support root level changes in __resolve_indirect_ref
Btrfs: avoid waiting for delayed refs when we must not
The tree log stuff can have allocated space that we end up having split
across a bitmap and a real extent. The free space code does not deal with
this, it assumes that if it finds an extent or bitmap entry that the entire
range must fall within the entry it finds. This isn't necessarily the case,
so rework the remove function so it can handle this case properly. This
fixed two panics the user hit, first in the case where the space was
initially in a bitmap and then in an extent entry, and then the reverse
case. Thanks,
Reported-and-tested-by: Shaun Reich <sreich@kde.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull vfs changes from Al Viro.
"A lot of misc stuff. The obvious groups:
* Miklos' atomic_open series; kills the damn abuse of
->d_revalidate() by NFS, which was the major stumbling block for
all work in that area.
* ripping security_file_mmap() and dealing with deadlocks in the
area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
general.
* ->encode_fh() switched to saner API; insane fake dentry in
mm/cleancache.c gone.
* assorted annotations in fs (endianness, __user)
* parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
* ->update_time() work from Josef.
* other bits and pieces all over the place.
Normally it would've been in two or three pull requests, but
signal.git stuff had eaten a lot of time during this cycle ;-/"
Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
nfs: don't open in ->d_revalidate
vfs: retry last component if opening stale dentry
vfs: nameidata_to_filp(): don't throw away file on error
vfs: nameidata_to_filp(): inline __dentry_open()
vfs: do_dentry_open(): don't put filp
vfs: split __dentry_open()
vfs: do_last() common post lookup
vfs: do_last(): add audit_inode before open
vfs: do_last(): only return EISDIR for O_CREAT
vfs: do_last(): check LOOKUP_DIRECTORY
vfs: do_last(): make ENOENT exit RCU safe
vfs: make follow_link check RCU safe
vfs: do_last(): use inode variable
vfs: do_last(): inline walk_component()
vfs: do_last(): make exit RCU safe
vfs: split do_lookup()
Btrfs: move over to use ->update_time
fs: introduce inode operation ->update_time
reiserfs: get rid of resierfs_sync_super
reiserfs: mark the superblock as dirty a bit later
...
When we write out the free space cache we will write out everything that is
in our in memory tree, and then we will just walk the pinned extents tree
and write anything we see there. The problem with this is that during
normal operations the pinned extents will be merged back into the free space
tree normally, and then we can allocate space from the merged areas and
commit them to the tree log. If we crash and replay the tree log we will
crash again because the tree log will try to free up space from what looks
like 2 seperate but contiguous entries, since one entry is from the original
free space cache and the other was a pinned extent that was merged back. To
fix this we just need to walk the free space tree after we load it and merge
contiguous entries back together. This will keep the tree log stuff from
breaking and it will make the allocator behave more nicely. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
We noticed that the ordered extent completion doesn't really rely on having
a page and that it could be done independantly of ending the writeback on a
page. This patch makes us not do the threaded endio stuff for normal
buffered writes and direct writes so we can end page writeback as soon as
possible (in irq context) and only start threads to do the ordered work when
it is actually done. Compression needs to be reworked some to take
advantage of this as well, but atm it has to do a find_get_page in its endio
handler so it must be done in its own thread. This makes direct writes
quite a bit faster. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Pull the minimal btrfs branch from Chris Mason:
"We have a use-after-free in there, along with errors when mount -o
discard is enabled, and a BUG_ON(we should compile with UP more
often)."
* 'for-linus-min' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: use commit root when loading free space cache
Btrfs: fix use-after-free in __btrfs_end_transaction
Btrfs: check return value of bio_alloc() properly
Btrfs: remove lock assert from get_restripe_target()
Btrfs: fix eof while discarding extents
Btrfs: fix uninit variable in repair_eb_io_failure
Revert "Btrfs: increase the global block reserve estimates"
A user reported that booting his box up with btrfs root on 3.4 was way
slower than on 3.3 because I removed the ideal caching code. It turns out
that we don't load the free space cache if we're in a commit for deadlock
reasons, but since we're reading the cache and it hasn't changed yet we are
safe reading the inode and free space item from the commit root, so do that
and remove all of the deadlock checks so we don't unnecessarily skip loading
the free space cache. The user reported this fixed the slowness. Thanks,
Tested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Pull btrfs fixes and features from Chris Mason:
"We've merged in the error handling patches from SuSE. These are
already shipping in the sles kernel, and they give btrfs the ability
to abort transactions and go readonly on errors. It involves a lot of
churn as they clarify BUG_ONs, and remove the ones we now properly
deal with.
Josef reworked the way our metadata interacts with the page cache.
page->private now points to the btrfs extent_buffer object, which
makes everything faster. He changed it so we write an whole extent
buffer at a time instead of allowing individual pages to go down,,
which will be important for the raid5/6 code (for the 3.5 merge
window ;)
Josef also made us more aggressive about dropping pages for metadata
blocks that were freed due to COW. Overall, our metadata caching is
much faster now.
We've integrated my patch for metadata bigger than the page size.
This allows metadata blocks up to 64KB in size. In practice 16K and
32K seem to work best. For workloads with lots of metadata, this cuts
down the size of the extent allocation tree dramatically and fragments
much less.
Scrub was updated to support the larger block sizes, which ended up
being a fairly large change (thanks Stefan Behrens).
We also have an assortment of fixes and updates, especially to the
balancing code (Ilya Dryomov), the back ref walker (Jan Schmidt) and
the defragging code (Liu Bo)."
Fixed up trivial conflicts in fs/btrfs/scrub.c that were just due to
removal of the second argument to k[un]map_atomic() in commit
7ac687d9e0.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (75 commits)
Btrfs: update the checks for mixed block groups with big metadata blocks
Btrfs: update to the right index of defragment
Btrfs: do not bother to defrag an extent if it is a big real extent
Btrfs: add a check to decide if we should defrag the range
Btrfs: fix recursive defragment with autodefrag option
Btrfs: fix the mismatch of page->mapping
Btrfs: fix race between direct io and autodefrag
Btrfs: fix deadlock during allocating chunks
Btrfs: show useful info in space reservation tracepoint
Btrfs: don't use crc items bigger than 4KB
Btrfs: flush out and clean up any block device pages during mount
btrfs: disallow unequal data/metadata blocksize for mixed block groups
Btrfs: enhance superblock sanity checks
Btrfs: change scrub to support big blocks
Btrfs: minor cleanup in scrub
Btrfs: introduce common define for max number of mirrors
Btrfs: fix infinite loop in btrfs_shrink_device()
Btrfs: fix memory leak in resolver code
Btrfs: allow dup for data chunks in mixed mode
Btrfs: validate target profiles only if we are going to use them
...
btrfs currently handles most errors with BUG_ON. This patch is a work-in-
progress but aims to handle most errors other than internal logic
errors and ENOMEM more gracefully.
This iteration prevents most crashes but can run into lockups with
the page lock on occasion when the timing "works out."
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
lock_extent and unlock_extent are always called with GFP_NOFS, drop the
argument and use GFP_NOFS consistently.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Pull trivial tree from Jiri Kosina:
"It's indeed trivial -- mostly documentation updates and a bunch of
typo fixes from Masanari.
There are also several linux/version.h include removals from Jesper."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (101 commits)
kcore: fix spelling in read_kcore() comment
constify struct pci_dev * in obvious cases
Revert "char: Fix typo in viotape.c"
init: fix wording error in mm_init comment
usb: gadget: Kconfig: fix typo for 'different'
Revert "power, max8998: Include linux/module.h just once in drivers/power/max8998_charger.c"
writeback: fix fn name in writeback_inodes_sb_nr_if_idle() comment header
writeback: fix typo in the writeback_control comment
Documentation: Fix multiple typo in Documentation
tpm_tis: fix tis_lock with respect to RCU
Revert "media: Fix typo in mixer_drv.c and hdmi_drv.c"
Doc: Update numastat.txt
qla4xxx: Add missing spaces to error messages
compiler.h: Fix typo
security: struct security_operations kerneldoc fix
Documentation: broken URL in libata.tmpl
Documentation: broken URL in filesystems.tmpl
mtd: simplify return logic in do_map_probe()
mm: fix comment typo of truncate_inode_pages_range
power: bq27x00: Fix typos in comment
...
Quoth Chris:
"This is later than I wanted because I got backed up running through
btrfs bugs from the Oracle QA teams. But they are all bug fixes that
we've queued and tested since rc1.
Nothing in particular stands out, this just reflects bug fixing and QA
done in parallel by all the btrfs developers. The most user visible
of these is:
Btrfs: clear the extent uptodate bits during parent transid failures
Because that helps deal with out of date drives (say an iscsi disk
that has gone away and come back). The old code wasn't always
properly retrying the other mirror for this type of failure."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
Btrfs: fix compiler warnings on 32 bit systems
Btrfs: increase the global block reserve estimates
Btrfs: clear the extent uptodate bits during parent transid failures
Btrfs: add extra sanity checks on the path names in btrfs_mksubvol
Btrfs: make sure we update latest_bdev
Btrfs: improve error handling for btrfs_insert_dir_item callers
Btrfs: be less strict on finding next node in clear_extent_bit
Btrfs: fix a bug on overcommit stuff
Btrfs: kick out redundant stuff in convert_extent_bit
Btrfs: skip states when they does not contain bits to clear
Btrfs: check return value of lookup_extent_mapping() correctly
Btrfs: fix deadlock on page lock when doing auto-defragment
Btrfs: fix return value check of extent_io_ops
btrfs: honor umask when creating subvol root
btrfs: silence warning in raid array setup
btrfs: fix structs where bitfields and spinlock/atomic share 8B word
btrfs: delalloc for page dirtied out-of-band in fixup worker
Btrfs: fix memory leak in load_free_space_cache()
btrfs: don't check DUP chunks twice
Btrfs: fix trim 0 bytes after a device delete
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix reservations in btrfs_page_mkwrite
Btrfs: advance window_start if we're using a bitmap
btrfs: mask out gfp flags in releasepage
Btrfs: fix enospc error caused by wrong checks of the chunk
Btrfs: do not defrag a file partially
Btrfs: fix warning for 32-bit build of fs/btrfs/check-integrity.c
Btrfs: use cluster->window_start when allocating from a cluster bitmap
Btrfs: Check for NULL page in extent_range_uptodate
btrfs: Fix busyloops in transaction waiting code
Btrfs: make sure a bitmap has enough bytes
Btrfs: fix uninit warning in backref.c
If we span a long area in a bitmap we could end up taking a lot of time
searching to the next free area if we're searching from the original
window_start, so advance window_start in order to make sure we don't do any
superficial searching. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We specifically set window_start in the cluster struct to indicate where the
cluster starts in a bitmap, but we've been using min_start to indicate where
we're searching from. This is usually the start of the blockgroup, so
essentially means we're constantly searching from the start of any bitmap we
find, which completely negates all the trouble we go to in order to setup a
cluster. So start using window_start to make sure we actually use the area we
found. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We have only been checking for min_bytes available in bitmap entries, but we
won't successfully setup a bitmap cluster unless it has at least bytes in the
bitmap, so in the common case min_bytes is 4k and we want something like 2MB, so
if there are a bunch of bitmap entries with less than 2mb's in them, we'll
search all them anyway, which is suboptimal. Fix this check. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (62 commits)
Btrfs: use larger system chunks
Btrfs: add a delalloc mutex to inodes for delalloc reservations
Btrfs: space leak tracepoints
Btrfs: protect orphan block rsv with spin_lock
Btrfs: add allocator tracepoints
Btrfs: don't call btrfs_throttle in file write
Btrfs: release space on error in page_mkwrite
Btrfs: fix btrfsck error 400 when truncating a compressed
Btrfs: do not use btrfs_end_transaction_throttle everywhere
Btrfs: add balance progress reporting
Btrfs: allow for resuming restriper after it was paused
Btrfs: allow for canceling restriper
Btrfs: allow for pausing restriper
Btrfs: add skip_balance mount option
Btrfs: recover balance on mount
Btrfs: save balance parameters to disk
Btrfs: soft profile changing mode (aka soft convert)
Btrfs: implement online profile changing
Btrfs: do not reduce profile in do_chunk_alloc()
Btrfs: virtual address space subset filter
...
Fix up trivial conflict in fs/btrfs/ioctl.c due to the use of the new
mnt_drop_write_file() helper.
I used these tracepoints when figuring out what the cluster stuff was doing, so
add them to mainline in case we need to profile this stuff again. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
There are various bugs in block group trimming:
- It may trim from offset smaller than user-specified offset.
- It may trim beyond user-specified range.
- It may leak free space for extents smaller than specified minlen.
- It may truncate the last trimmed extent thus leak free space.
- With mixed extents+bitmaps, some extents may not be trimmed.
- With mixed extents+bitmaps, some bitmaps may not be trimmed (even
none will be trimmed). Even for those trimmed, not all the free space
in the bitmaps will be trimmed.
I rewrite btrfs_trim_block_group() and break it into two functions.
One is to trim extents only, and the other is to trim bitmaps only.
Before patching:
# fstrim -v /mnt/
/mnt/: 1496465408 bytes were trimmed
After patching:
# fstrim -v /mnt/
/mnt/: 2193768448 bytes were trimmed
And this matches the total free space:
# btrfs fi df /mnt
Data: total=3.58GB, used=1.79GB
System, DUP: total=8.00MB, used=4.00KB
System: total=4.00MB, used=0.00
Metadata, DUP: total=205.12MB, used=97.14MB
Metadata: total=8.00MB, used=0.00
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
If we run into some failure path in io_ctl_prepare_pages(),
io_ctl->pages[] array may have some NULL pointers.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
I got this while running xfstests:
[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600
We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits)
Kconfig: acpi: Fix typo in comment.
misc latin1 to utf8 conversions
devres: Fix a typo in devm_kfree comment
btrfs: free-space-cache.c: remove extra semicolon.
fat: Spelling s/obsolate/obsolete/g
SCSI, pmcraid: Fix spelling error in a pmcraid_err() call
tools/power turbostat: update fields in manpage
mac80211: drop spelling fix
types.h: fix comment spelling for 'architectures'
typo fixes: aera -> area, exntension -> extension
devices.txt: Fix typo of 'VMware'.
sis900: Fix enum typo 'sis900_rx_bufer_status'
decompress_bunzip2: remove invalid vi modeline
treewide: Fix comment and string typo 'bufer'
hyper-v: Update MAINTAINERS
treewide: Fix typos in various parts of the kernel, and fix some comments.
clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR
gpio: Kconfig: drop unknown symbol 'CS5535_GPIO'
leds: Kconfig: Fix typo 'D2NET_V2'
sound: Kconfig: drop unknown symbol ARCH_CLPS7500
...
Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new
kconfig additions, close to removed commented-out old ones)
Parameterize clusters on minimum total size, minimum chunk size and
minimum contiguous size for at least one chunk, without limits on
cluster, window or gap sizes. Don't tolerate any fragmentation for
SSD_SPREAD; accept it for metadata, but try to keep data dense.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The patch below removes an extra semicolon.
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
CC: Chris Mason <chris.mason@oracle.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The field that indicates the size of the largest contiguous chunk of
free space in the cluster is not initialized when setting up bitmaps,
it's only increased when we find a larger contiguous chunk. We end up
retaining a larger value than appropriate for highly-fragmented
clusters, which may cause pointless searches for large contiguous
groups, and even cause clusters that do not meet the density
requirements to be set up.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We're failing to create clusters with bitmaps because
setup_cluster_no_bitmap checks that the list is empty before inserting
the bitmap entry in the list for setup_cluster_bitmap, but the list
field is only initialized when it is restored from the on-disk free
space cache, or when it is written out to disk.
Besides a potential race condition due to the multiple use of the list
field, filesystem performance severely degrades over time: as we use
up all non-bitmap free extents, the try-to-set-up-cluster dance is
done at every metadata block allocation. For every block group, we
fail to set up a cluster, and after failing on them all up to twice,
we fall back to the much slower unclustered allocation.
To make matters worse, before the unclustered allocation, we try to
create new block groups until we reach the 1% threshold, which
introduces additional bitmaps and thus block groups that we'll iterate
over at each metadata block request.
The log replay code only partially loads block groups, since
the block group caching code is able to detect and deal with
extents the logging code has pinned down.
While the logging code is pinning down block groups, there is
a bogus WARN_ON we're hitting if the code wasn't able to find
an extent in the cache. This commit removes the warning because
it can happen any time there isn't a valid free space cache
for that block group.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When doing the io_ctl helpers to clean up the free space cache stuff I stopped
using our normal prepare_pages stuff, which means I of course forgot to do
things like set the pages extent mapped, which will cause us all sorts of
wonderful propblems. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
setup_cluster_no_bitmap() searches all the extents and bitmaps starting
from offset. Therefore if it returns -ENOSPC, all the bitmaps starting
from offset are in the bitmaps list, so it's sufficient to search from
this list in setup_cluser_bitmap().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Suppose there are two bitmaps [0, 256], [256, 512] and one extent
[100, 120] in the free space cache, and we want to setup a cluster
with offset=100, bytes=50.
In this case, there will be only one bitmap [256, 512] in the temporary
bitmaps list, and then setup_cluster_bitmap() won't search bitmap [0, 256].
The cause is, the list is constructed in setup_cluster_no_bitmap(),
and only bitmaps with bitmap_entry->offset >= offset will be added
into the list, and the very bitmap that convers offset has
bitmap_entry->offset <= offset.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
People have been running into a warning when loading space cache because the
page is already mapped when trying to read in a bitmap. The way we read in
entries and pages is kind of convoluted, so fix it so that io_ctl_read_entry
maps the entries if it needs to, and if it hits the end of the page it simply
unmaps the page. That way we can unconditionally unmap the io_ctl before
reading in the bitmap and we should stop hitting these warnings. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We no longer use the orphan block rsv for holding the reservation for truncating
the inode, so instead use the global block rsv and check to make sure it has
enough space for us to truncate the space. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_remove_free_space needs to make sure to set ret back to a
valid return value after setting it to EAGAIN, otherwise we return
it to the callers.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
I noticed we had a little bit of latency when writing out the space cache
inodes. It's because we flush it before we write anything in case we have dirty
pages already there. This doesn't matter though since we're just going to
overwrite the space, and there really shouldn't be any dirty pages anyway. This
makes some of my tests run a little bit faster. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Currently btrfs_block_rsv_check does 2 things, it will either refill a block
reserve like in the truncate or refill case, or it will check to see if there is
enough space in the global reserve and possibly refill it. However because of
overcommit we could be well overcommitting ourselves just to try and refill the
global reserve, when really we should just be committing the transaction. So
breack this out into btrfs_block_rsv_refill and btrfs_block_rsv_check. Refill
will try to reserve more metadata if it can and btrfs_block_rsv_check will not,
it will only tell you if the factor of the total space is still reserved.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Yeah yeah I know this is how we used to do it and then I changed it, but damnit
I'm changing it back. The fact is that writing out checksums will modify
metadata, which could cause us to dirty a block group we've already written out,
so we have to truncate it and all of it's checksums and re-write it which will
write new checksums which could dirty a blockg roup that has already been
written and you see where I'm going with this? This can cause unmount or really
anything that depends on a transaction to commit to take it's sweet damned time
to happen. So go back to the way it was, only this time we're specifically
setting NODATACOW because we can't go through the COW pathway anyway and we're
doing our own built-in cow'ing by truncating the free space cache. The other
new thing is once we truncate the old cache and preallocate the new space, we
don't need to do that song and dance at all for the rest of the transaction, we
can just overwrite the existing space with the new cache if the block group
changes for whatever reason, and the NODATACOW will let us do this fine. So
keep track of which transaction we last cleared our cache in and if we cleared
it in this transaction just say we're all setup and carry on. This survives
xfstests and stress.sh.
The inode cache will continue to use the normal csum infrastructure since it
only gets written once and there will be no more modifications to the fs tree in
a transaction commit.
Signed-off-by: Josef Bacik <josef@redhat.com>
We need to check the return value of filemap_write_and_wait in the space cache
writeout code. Also don't set the inode's generation until we're sure nothing
else is going to fail. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
In writing and reading the space cache we have one big loop that keeps track of
which page we are on and then a bunch of sizeable loops underneath this big loop
to try and read/write out properly. Especially in the write case this makes
things hugely complicated and hard to follow, and makes our error checking and
recovery equally as complex. So add a io_ctl struct with a bunch of helpers to
keep track of the pages we have, where we are, if we have enough space etc.
This unifies how we deal with the pages we're writing and keeps all the messy
tracking internal. This allows us to kill the big loops in both the read and
write case and makes reviewing and chaning the write and read paths much
simpler. I've run xfstests and stress.sh on this code and it survives. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
I noticed a slight bug where we will not bother writing out the block group
cache's space cache if it's space tree is empty. Since it could have a cluster
or pinned extents that need to be written out this is just not a valid test.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Johannes pointed out we were allocating only kernel pages for doing writes,
which is kind of a big deal if you are on 32bit and have more than a gig of ram.
So fix our allocations to use the mapping's gfp but still clear __GFP_FS so we
don't re-enter. Thanks,
Reported-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
The only thing that we need to have a trans handle for is in
reserve_metadata_bytes and thats to know how much flushing we can do. So
instead of passing it around, just check current->journal_info for a
trans_handle so we know if we can commit a transaction to try and free up space
or not. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Since free space inodes now use normal checksumming we need to make sure to
account for their metadata use. So reserve metadata space, and then if we fail
to write out the metadata we can just release it, otherwise it will be freed up
when the io completes. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Josef Bacik