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path: root/fs/btrfs/extent_map.c
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2013-05-06btrfs: make static code static & remove dead codeEric Sandeen
Big patch, but all it does is add statics to functions which are in fact static, then remove the associated dead-code fallout. removed functions: btrfs_iref_to_path() __btrfs_lookup_delayed_deletion_item() __btrfs_search_delayed_insertion_item() __btrfs_search_delayed_deletion_item() find_eb_for_page() btrfs_find_block_group() range_straddles_pages() extent_range_uptodate() btrfs_file_extent_length() btrfs_scrub_cancel_devid() btrfs_start_transaction_lflush() btrfs_print_tree() is left because it is used for debugging. btrfs_start_transaction_lflush() and btrfs_reada_detach() are left for symmetry. ulist.c functions are left, another patch will take care of those. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06Btrfs: fix bad extent loggingJosef Bacik
A user sent me a btrfs-image of a file system that was panicing on mount during the log recovery. I had originally thought these problems were from a bug in the free space cache code, but that was just a symptom of the problem. The problem is if your application does something like this [prealloc][prealloc][prealloc] the internal extent maps will merge those all together into one extent map, even though on disk they are 3 separate extents. So if you go to write into one of these ranges the extent map will be right since we use the physical extent when doing the write, but when we log the extents they will use the wrong sizes for the remainder prealloc space. If this doesn't happen to trip up the free space cache (which it won't in a lot of cases) then you will get bogus entries in your extent tree which will screw stuff up later. The data and such will still work, but everything else is broken. This patch fixes this by not allowing extents that are on the modified list to be merged. This has the side effect that we are no longer adding everything to the modified list all the time, which means we now have to call btrfs_drop_extents every time we log an extent into the tree. So this allows me to drop all this speciality code I was using to get around calling btrfs_drop_extents. With this patch the testcase I've created no longer creates a bogus file system after replaying the log. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-03-01btrfs: fixup/remove module.h usage as requiredPaul Gortmaker
We want to avoid module.h where posible, since it in turn includes nearly all of header space. This means removing it where it is not required, and using export.h where we are only exporting symbols via EXPORT_SYMBOL and friends. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-02-08Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "We've got corner cases for updating i_size that ceph was hitting, error handling for quotas when we run out of space, a very subtle snapshot deletion race, a crash while removing devices, and one deadlock between subvolume creation and the sb_internal code (thanks lockdep)." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: move d_instantiate outside the transaction during mksubvol Btrfs: fix EDQUOT handling in btrfs_delalloc_reserve_metadata Btrfs: fix possible stale data exposure Btrfs: fix missing i_size update Btrfs: fix race between snapshot deletion and getting inode Btrfs: fix missing release of the space/qgroup reservation in start_transaction() Btrfs: fix wrong sync_writers decrement in btrfs_file_aio_write() Btrfs: do not merge logged extents if we've removed them from the tree btrfs: don't try to notify udev about missing devices
2013-02-05Btrfs: do not merge logged extents if we've removed them from the treeJosef Bacik
You can run into this problem where if somebody is fsyncing and writing out the existing extents you will have removed the extent map from the em tree, but it's still valid for the current fsync so we go ahead and write it. The problem is we unconditionally try to merge it back into the em tree, but if we've removed it from the em tree that will cause use after free problems. Fix this to only merge if we are still a part of the tree. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-01-25Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "It turns out that we had two crc bugs when running fsx-linux in a loop. Many thanks to Josef, Miao Xie, and Dave Sterba for nailing it all down. Miao also has a new OOM fix in this v2 pull as well. Ilya fixed a regression Liu Bo found in the balance ioctls for pausing and resuming a running balance across drives. Josef's orphan truncate patch fixes an obscure corruption we'd see during xfstests. Arne's patches address problems with subvolume quotas. If the user destroys quota groups incorrectly the FS will refuse to mount. The rest are smaller fixes and plugs for memory leaks." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (30 commits) Btrfs: fix repeated delalloc work allocation Btrfs: fix wrong max device number for single profile Btrfs: fix missed transaction->aborted check Btrfs: Add ACCESS_ONCE() to transaction->abort accesses Btrfs: put csums on the right ordered extent Btrfs: use right range to find checksum for compressed extents Btrfs: fix panic when recovering tree log Btrfs: do not allow logged extents to be merged or removed Btrfs: fix a regression in balance usage filter Btrfs: prevent qgroup destroy when there are still relations Btrfs: ignore orphan qgroup relations Btrfs: reorder locks and sanity checks in btrfs_ioctl_defrag Btrfs: fix unlock order in btrfs_ioctl_rm_dev Btrfs: fix unlock order in btrfs_ioctl_resize Btrfs: fix "mutually exclusive op is running" error code Btrfs: bring back balance pause/resume logic btrfs: update timestamps on truncate() btrfs: fix btrfs_cont_expand() freeing IS_ERR em Btrfs: fix a bug when llseek for delalloc bytes behind prealloc extents Btrfs: fix off-by-one in lseek ...
2013-01-24Btrfs: do not allow logged extents to be merged or removedJosef Bacik
We drop the extent map tree lock while we're logging extents, so somebody could come in and merge another extent into this one and screw up our logging, or they could even remove us from the list which would keep us from logging the extent or freeing our ref on it, so we need to make sure to not clear LOGGING until after the extent is logged, and then we can merge it to adjacent extents. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-12-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs update from Chris Mason: "A big set of fixes and features. In terms of line count, most of the code comes from Stefan, who added the ability to replace a single drive in place. This is different from how btrfs normally replaces drives, and is much much much faster. Josef is plowing through our synchronous write performance. This pull request does not include the DIO_OWN_WAITING patch that was discussed on the list, but it has a number of other improvements to cut down our latencies and CPU time during fsync/O_DIRECT writes. Miao Xie has a big series of fixes and is spreading out ordered operations over more CPUs. This improves performance and reduces contention. I've put in fixes for error handling around hash collisions. These are going back to individual stable kernels as I test against them. Otherwise we have a lot of fixes and cleanups, thanks everyone! raid5/6 is being rebased against the device replacement code. I'll have it posted this Friday along with a nice series of benchmarks." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (115 commits) Btrfs: fix a bug of per-file nocow Btrfs: fix hash overflow handling Btrfs: don't take inode delalloc mutex if we're a free space inode Btrfs: fix autodefrag and umount lockup Btrfs: fix permissions of empty files not affected by umask Btrfs: put raid properties into global table Btrfs: fix BUG() in scrub when first superblock reading gives EIO Btrfs: do not call file_update_time in aio_write Btrfs: only unlock and relock if we have to Btrfs: use tokens where we can in the tree log Btrfs: optimize leaf_space_used Btrfs: don't memset new tokens Btrfs: only clear dirty on the buffer if it is marked as dirty Btrfs: move checks in set_page_dirty under DEBUG Btrfs: log changed inodes based on the extent map tree Btrfs: add path->really_keep_locks Btrfs: do not mark ems as prealloc if we are writing to them Btrfs: keep track of the extents original block length Btrfs: inline csums if we're fsyncing Btrfs: don't bother copying if we're only logging the inode ...
2012-12-16Btrfs: log changed inodes based on the extent map treeJosef Bacik
We don't really need to copy extents from the source tree since we have all of the information already available to us in the extent_map tree. So instead just write the extents straight to the log tree and don't bother to copy the extent items from the source tree. Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-12-16Btrfs: do not mark ems as prealloc if we are writing to themJosef Bacik
We are going to use EM's to log extents in the future, so we need to not mark them as prealloc if they aren't actually prealloc extents. Instead mark them with FILLING so we know to ammend mod_start/mod_len and that way we don't confuse the extent logging code. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-10-30btrfs: unpin_extent_cache: fix the typo and unnecessary arguementsLiu Bo
- unpint->unpin - prealloc is no more used Signed-off-by: Liu Bo <liub.liubo@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-04Btrfs: do not hold the write_lock on the extent tree while loggingJosef Bacik
Dave Sterba pointed out a sleeping while atomic bug while doing fsync. This is because I'm an idiot and didn't realize that rwlock's were spin locks, so we've been holding this thing while doing allocations and such which is not good. This patch fixes this by dropping the write lock before we do anything heavy and re-acquire it when it is done. We also need to take a ref on the em's in case their corresponding pages are evicted and mark them as being logged so that releasepage does not remove them and doesn't remove them from our local list. Thanks, Reported-by: Dave Sterba <dave@jikos.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01btrfs: polish names of kmem cachesDavid Sterba
Usecase: watch 'grep btrfs < /proc/slabinfo' easy to watch all caches in one go. Signed-off-by: David Sterba <dsterba@suse.cz>
2012-10-01Btrfs: improve fsync by filtering extents that we wantLiu Bo
This is based on Josef's "Btrfs: turbo charge fsync". The above Josef's patch performs very good in random sync write test, because we won't have too much extents to merge. However, it does not performs good on the test: dd if=/dev/zero of=foobar bs=4k count=12500 oflag=sync The reason is when we do sequencial sync write, we need to merge the current extent just with the previous one, so that we can get accumulated extents to log: A(4k) --> AA(8k) --> AAA(12k) --> AAAA(16k) ... So we'll have to flush more and more checksum into log tree, which is the bottleneck according to my tests. But we can avoid this by telling fsync the real extents that are needed to be logged. With this, I did the above dd sync write test (size=50m), w/o (orig) w/ (josef's) w/ (this) SATA 104KB/s 109KB/s 121KB/s ramdisk 1.5MB/s 1.5MB/s 10.7MB/s (613%) Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
2012-10-01Btrfs: turbo charge fsyncJosef Bacik
At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2011-08-01Btrfs: clean up code for merging extent mapsLi Zefan
unpin_extent_cache() and add_extent_mapping() shares the same code that merges extent maps. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-01Btrfs: clean up code for extent_map lookupLi Zefan
lookup_extent_map() and search_extent_map() can share most of code. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-08-01Btrfs: clean up search_extent_mapping()Li Zefan
rb_node returned by __tree_search() can be a valid pointer or NULL, but won't be some errno. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-02btrfs: drop gfp parameter from alloc_extent_mapDavid Sterba
pass GFP_NOFS directly to kmem_cache_alloc Signed-off-by: David Sterba <dsterba@suse.cz>
2011-05-02btrfs: drop unused parameter from extent_map_tree_initDavid Sterba
the GFP flags are not stored anywhere and all allocations are done via alloc_extent_map(GFP_NOFS). Signed-off-by: David Sterba <dsterba@suse.cz>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-02-14Btrfs: check return value of alloc_extent_map()Tsutomu Itoh
I add the check on the return value of alloc_extent_map() to several places. In addition, alloc_extent_map() returns only the address or NULL. Therefore, check by IS_ERR() is unnecessary. So, I remove IS_ERR() checking. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-22btrfs: Allow to add new compression algorithmLi Zefan
Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-10-29Btrfs: Use ERR_CAST helpersJulia Lawall
Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)). The former makes more clear what is the purpose of the operation, which otherwise looks like a no-op. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ type T; T x; identifier f; @@ T f (...) { <+... - ERR_PTR(PTR_ERR(x)) + x ...+> } @@ expression x; @@ - ERR_PTR(PTR_ERR(x)) + ERR_CAST(x) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: kfree correct pointer during mount option parsing Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULL
2010-03-08Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULLEric Paris
btrfs inialize rb trees in quite a number of places by settin rb_node = NULL; The problem with this is that 17d9ddc72fb8bba0d4f678 in the linux-next tree adds a new field to that struct which needs to be NULL for the new rbtree library code to work properly. This patch uses RB_ROOT as the intializer so all of the relevant fields will be NULL'd. Without the patch I get a panic. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: check total number of devices when removing missing Btrfs: check return value of open_bdev_exclusive properly Btrfs: do not mark the chunk as readonly if in degraded mode Btrfs: run orphan cleanup on default fs root Btrfs: fix a memory leak in btrfs_init_acl Btrfs: Use correct values when updating inode i_size on fallocate Btrfs: remove tree_search() in extent_map.c Btrfs: Add mount -o compress-force
2010-01-28Btrfs: remove tree_search() in extent_map.cMiao Xie
This patch removes tree_search() in extent_map.c because it is not called by anything. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-07Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: kernel/irq/chip.c
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-11Btrfs: avoid null deref in unpin_extent_cache()Dan Carpenter
I re-orderred the checks to avoid dereferencing "em" if it was null. Found by smatch static checker. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-18Btrfs: search for an allocation hint while filling file COWChris Mason
The allocator has some nice knobs for sending hints about where to try and allocate new blocks, but when we're doing file allocations we're not sending any hint at all. This commit adds a simple extent map search to see if we can quickly and easily find a hint for the allocator. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: Fix extent replacment raceChris Mason
Data COW means that whenever we write to a file, we replace any old extent pointers with new ones. There was a window where a readpage might find the old extent pointers on disk and cache them in the extent_map tree in ram in the middle of a given write replacing them. Even though both the readpage and the write had their respective bytes in the file locked, the extent readpage inserts may cover more bytes than it had locked down. This commit closes the race by keeping the new extent pinned in the extent map tree until after the on-disk btree is properly setup with the new extent pointers. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: switch extent_map to a rw lockChris Mason
There are two main users of the extent_map tree. The first is regular file inodes, where it is evenly spread between readers and writers. The second is the chunk allocation tree, which maps blocks from logical addresses to phyiscal ones, and it is 99.99% reads. The mapping tree is a point of lock contention during heavy IO workloads, so this commit switches things to a rw lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24Btrfs: kill btrfs_cache_createChristoph Hellwig
Just use kmem_cache_create directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24Btrfs: don't export symbolsChristoph Hellwig
Currently the extent_map code is only for btrfs so don't export it's symbols. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02Btrfs: remove dead codeDan Carpenter
merge is always NULL at this point. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: removed unused #include <version.h>'sHuang Weiyi
Removed unused #include <version.h>'s in btrfs Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05Btrfs: Fix checkpatch.pl warningsChris Mason
There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29Btrfs: Add zlib compression supportChris Mason
This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-29Btrfs: add and improve commentsChris Mason
This improves the comments at the top of many functions. It didn't dive into the guts of functions because I was trying to avoid merging problems with the new allocator and back reference work. extent-tree.c and volumes.c were both skipped, and there is definitely more work todo in cleaning and commenting the code. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix add_extent_mapping to check for duplicates across the whole rangeChris Mason
add_extent_mapping was allowing the insertion of overlapping extents. This never used to happen because it only inserted the extents from disk and those were never overlapping. But, with the data=ordered code, the disk and memory representations of the file are not the same. add_extent_mapping needs to ensure a new extent does not overlap before it inserts. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Use assert_spin_locked instead of spin_trylockDavid Woodhouse
On UP systems spin_trylock always succeeds Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix some data=ordered related data corruptionsChris Mason
Stress testing was showing data checksum errors, most of which were caused by a lookup bug in the extent_map tree. The tree was caching the last pointer returned, and searches would check the last pointer first. But, search callers also expect the search to return the very first matching extent in the range, which wasn't always true with the last pointer usage. For now, the code to cache the last return value is just removed. It is easy to fix, but I think lookups are rare enough that it isn't required anymore. This commit also replaces do_sync_mapping_range with a local copy of the related functions. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Keep extent mappings in ram until pending ordered extents are doneChris Mason
It was possible for stale mappings from disk to be used instead of the new pending ordered extent. This adds a flag to the extent map struct to keep it pinned until the pending ordered extent is actually on disk. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: New data=ordered implementationChris Mason
The old data=ordered code would force commit to wait until all the data extents from the transaction were fully on disk. This introduced large latencies into the commit and stalled new writers in the transaction for a long time. The new code changes the way data allocations and extents work: * When delayed allocation is filled, data extents are reserved, and the extent bit EXTENT_ORDERED is set on the entire range of the extent. A struct btrfs_ordered_extent is allocated an inserted into a per-inode rbtree to track the pending extents. * As each page is written EXTENT_ORDERED is cleared on the bytes corresponding to that page. * When all of the bytes corresponding to a single struct btrfs_ordered_extent are written, The previously reserved extent is inserted into the FS btree and into the extent allocation trees. The checksums for the file data are also updated. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: kerneldoc comments for extent_map.cChristoph Hellwig
Add kerneldoc comments for all exported functions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25btrfs: fix strange indentation in lookup_extent_mappingChristoph Hellwig
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Split the extent_map code into two partsChris Mason
There is now extent_map for mapping offsets in the file to disk and extent_io for state tracking, IO submission and extent_bufers. The new extent_map code shifts from [start,end] pairs to [start,len], and pushes the locking out into the caller. This allows a few performance optimizations and is easier to use. A number of extent_map usage bugs were fixed, mostly with failing to remove extent_map entries when changing the file. Signed-off-by: Chris Mason <chris.mason@oracle.com>