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2020-05-06gfs2: fix withdraw sequence deadlockBob Peterson
After a gfs2 file system withdraw, any attempt to read metadata is automatically rejected by function gfs2_meta_read() except for reads of the journal inode. This turns out to be a problem because function signal_our_withdraw() repeatedly calls check_journal_clean() which reads the metadata (both its dinode and indirect blocks) to see if the entire journal is mapped. The dinode read works, but reading the indirect blocks returns -EIO which gets sent back up and causes a consistency error. This results in withdraw-from-withdraw, which becomes a deadlock. This patch changes the test in gfs2_meta_read() to allow all metadata reads for the journal. Instead of checking the journal block, it now checks for the journal inode glock which is the same for all blocks in the journal. This allows check_journal_clean() to properly check the journal without trying to withdraw recursively. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-02-27gfs2: Force withdraw to replay journals and wait for it to finishBob Peterson
When a node withdraws from a file system, it often leaves its journal in an incomplete state. This is especially true when the withdraw is caused by io errors writing to the journal. Before this patch, a withdraw would try to write a "shutdown" record to the journal, tell dlm it's done with the file system, and none of the other nodes know about the problem. Later, when the problem is fixed and the withdrawn node is rebooted, it would then discover that its own journal was incomplete, and replay it. However, replaying it at this point is almost guaranteed to introduce corruption because the other nodes are likely to have used affected resource groups that appeared in the journal since the time of the withdraw. Replaying the journal later will overwrite any changes made, and not through any fault of dlm, which was instructed during the withdraw to release those resources. This patch makes file system withdraws seen by the entire cluster. Withdrawing nodes dequeue their journal glock to allow recovery. The remaining nodes check all the journals to see if they are clean or in need of replay. They try to replay dirty journals, but only the journals of withdrawn nodes will be "not busy" and therefore available for replay. Until the journal replay is complete, no i/o related glocks may be given out, to ensure that the replay does not cause the aforementioned corruption: We cannot allow any journal replay to overwrite blocks associated with a glock once it is held. The "live" glock which is now used to signal when a withdraw occurs. When a withdraw occurs, the node signals its withdraw by dequeueing the "live" glock and trying to enqueue it in EX mode, thus forcing the other nodes to all see a demote request, by way of a "1CB" (one callback) try lock. The "live" glock is not granted in EX; the callback is only just used to indicate a withdraw has occurred. Note that all nodes in the cluster must wait for the recovering node to finish replaying the withdrawing node's journal before continuing. To this end, it checks that the journals are clean multiple times in a retry loop. Also note that the withdraw function may be called from a wide variety of situations, and therefore, we need to take extra precautions to make sure pointers are valid before using them in many circumstances. We also need to take care when glocks decide to withdraw, since the withdraw code now uses glocks. Also, before this patch, if a process encountered an error and decided to withdraw, if another process was already withdrawing, the second withdraw would be silently ignored, which set it free to unlock its glocks. That's correct behavior if the original withdrawer encounters further errors down the road. But if secondary waiters don't wait for the journal replay, unlocking glocks will allow other nodes to use them, despite the fact that the journal containing those blocks is being replayed. The replay needs to finish before our glocks are released to other nodes. IOW, secondary withdraws need to wait for the first withdraw to finish. For example, if an rgrp glock is unlocked by a process that didn't wait for the first withdraw, a journal replay could introduce file system corruption by replaying a rgrp block that has already been granted to a different cluster node. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2019-11-14gfs2: Introduce function gfs2_withdrawnBob Peterson
Add function gfs2_withdrawn and replace all checks for the SDF_WITHDRAWN bit to call it. This does not change the logic or function of gfs2, and it facilitates later improvements to the withdraw sequence. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-06-27gfs2: Rename SDF_SHUTDOWN to SDF_WITHDRAWNBob Peterson
Before this patch, the superblock flag indicating when a file system is withdrawn was called SDF_SHUTDOWN. This patch simply renames it to the more obvious SDF_WITHDRAWN. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398Thomas Gleixner
Based on 1 normalized pattern(s): this copyrighted material is made available to anyone wishing to use modify copy or redistribute it subject to the terms and conditions of the gnu general public license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 44 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-30block: remove the i argument to bio_for_each_segment_allChristoph Hellwig
We only have two callers that need the integer loop iterator, and they can easily maintain it themselves. Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: David Sterba <dsterba@suse.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Coly Li <colyli@suse.de> Reviewed-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15block: allow bio_for_each_segment_all() to iterate over multi-page bvecMing Lei
This patch introduces one extra iterator variable to bio_for_each_segment_all(), then we can allow bio_for_each_segment_all() to iterate over multi-page bvec. Given it is just one mechannical & simple change on all bio_for_each_segment_all() users, this patch does tree-wide change in one single patch, so that we can avoid to use a temporary helper for this conversion. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-21gfs2: Don't withdraw under a spin lockAndreas Gruenbacher
In two places, the gfs2_io_error_bh macro is called while holding the sd_ail_lock spin lock. This isn't allowed because gfs2_io_error_bh withdraws the filesystem, which can sleep because it issues a uevent. To fix that, add a gfs2_io_error_bh_wd macro that does withdraw the filesystem and change gfs2_io_error_bh to not withdraw the filesystem. In those places where the new gfs2_io_error_bh is used, withdraw the filesystem after releasing sd_ail_lock. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Reviewed-by: Andrew Price <anprice@redhat.com>
2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds
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 ...
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig
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>
2017-07-21gfs2: add flag REQ_PRIO for metadata I/OColy Li
When gfs2 does metadata I/O, only REQ_META is used as a metadata hint of the bio. But flag REQ_META is just a hint for block trace, not for block layer code to handle a bio as metadata request. For some of metadata I/Os of gfs2, A REQ_PRIO flag on the metadata bio would be very informative to block layer code. For example, if bcache is used as a I/O cache for gfs2, it will be possible for bcache code to get the hint and cache the pre-fetched metadata blocks on cache device. This behavior may be helpful to improve metadata I/O performance if the following requests hit the cache. Here are the locations in gfs2 code where a REQ_PRIO flag should be added, - All places where REQ_READAHEAD is used, gfs2 code uses this flag for metadata read ahead. - In gfs2_meta_rq() where the first metadata block is read in. - In gfs2_write_buf_to_page(), read in quota metadata blocks to have them up to date. These metadata blocks are probably to be accessed again in future, adding a REQ_PRIO flag may have bcache to keep such metadata in fast cache device. For system without a cache layer, REQ_PRIO can still provide hint to block layer to handle metadata requests more properly. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-07-17GFS2: Prevent double brelse in gfs2_meta_indirect_bufferBob Peterson
Before this patch, problems reading in indirect buffers would send an IO error back to the caller, and release the buffer_head with brelse() in function gfs2_meta_indirect_buffer, however, it would still return the address of the buffer_head it released. After the error was discovered, function gfs2_block_map would call function release_metapath to free all buffers. That checked: if (mp->mp_bh[i] == NULL) but since the value was set after the error, it was non-zero, so brelse was called a second time. This resulted in the following error: kernel: WARNING: at fs/buffer.c:1224 __brelse+0x3a/0x40() (Tainted: G W -- ------------ ) kernel: Hardware name: RHEV Hypervisor kernel: VFS: brelse: Trying to free free buffer This patch changes gfs2_meta_indirect_buffer so it only sets the buffer_head pointer in cases where it isn't released. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig
Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-21Merge tag 'gfs2-4.11.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull GFS2 updates from Robert Peterson: "We've got eight GFS2 patches for this merge window: - Andy Price submitted a patch to make gfs2_write_full_page a static function. - Dan Carpenter submitted a patch to fix a ERR_PTR thinko. Three patches fix bugs related to deleting very large files, which cause GFS2 to run out of journal space: - The first one prevents GFS2 delete operation from requesting too much journal space. - The second one fixes a problem whereby GFS2 can hang because it wasn't taking journal space demand into its calculations. - The third one wakes up IO waiters when a flush is done to restart processes stuck waiting for journal space to become available. The final three patches are a performance improvement related to spin_lock contention between multiple writers: - The "tr_touched" variable was switched to a flag to be more atomic and eliminate the possibility of some races. - Function meta_lo_add was moved inline with its only caller to make the code more readable and efficient. - Contention on the gfs2_log_lock spinlock was greatly reduced by avoiding the lock altogether in cases where we don't really need it: buffers that already appear in the appropriate metadata list for the journal. Many thanks to Steve Whitehouse for the ideas and principles behind these patches" * tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Make gfs2_write_full_page static GFS2: Reduce contention on gfs2_log_lock GFS2: Inline function meta_lo_add GFS2: Switch tr_touched to flag in transaction GFS2: Wake up io waiters whenever a flush is done GFS2: Made logd daemon take into account log demand GFS2: Limit number of transaction blocks requested for truncates GFS2: Fix reference to ERR_PTR in gfs2_glock_iter_next
2017-01-27GFS2: Switch tr_touched to flag in transactionBob Peterson
This patch eliminates the int variable tr_touched in favor of a new flag in the transaction. This is a step toward reducing contention on the gfs2_log_lock spin_lock. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2016-11-02writeback: add wbc_to_write_flags()Jens Axboe
Add wbc_to_write_flags(), which returns the write modifier flags to use, based on a struct writeback_control. No functional changes in this patch, but it prepares us for factoring other wbc fields for write type. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-11-01block,fs: use REQ_* flags directlyChristoph Hellwig
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags directly. Where applicable this also drops usage of the bio_set_op_attrs wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-18gfs2: Fix extended attribute readahead optimizationAndreas Gruenbacher
Commit 39b0555f didn't check for a failing bio_add_page in gfs2_submit_bhs. This could cause I/O requests to get lost, and the affected buffer heads to stay locked forever. Fix that by submitting the current bio and allocating another one when bio_add_page fails. (It is guaranteed that we can at least add one page to a bio.) Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2016-07-20block: get rid of bio_rw and READAChristoph Hellwig
These two are confusing leftover of the old world order, combining values of the REQ_OP_ and REQ_ namespaces. For callers that don't special case we mostly just replace bi_rw with bio_data_dir or op_is_write, except for the few cases where a switch over the REQ_OP_ values makes more sense. Any check for READA is replaced with an explicit check for REQ_RAHEAD. Also remove the READA alias for REQ_RAHEAD. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07gfs2: use bio op accessorsMike Christie
Separate the op from the rq_flag_bits and have gfs2 set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07fs: have ll_rw_block users pass in op and flags separatelyMike Christie
This has ll_rw_block users pass in the operation and flags separately, so ll_rw_block can setup the bio op and bi_rw flags on the bio that is submitted. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07fs: have submit_bh users pass in op and flags separatelyMike Christie
This has submit_bh users pass in the operation and flags separately, so submit_bh_wbc can setup the bio op and bi_rw flags on the bio that is submitted. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block/fs/drivers: remove rw argument from submit_bioMike Christie
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-20Merge tag 'gfs2-4.7.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull GFS2 updates from Bob Peterson: "We've got nine patches this time: - Abhi Das has two patches that fix a GFS2 splice issue (and an adjustment). - Ben Marzinski has a patch which allows the proper unmount of a GFS2 file system after hitting a withdraw error. - I have a patch to fix a problem where GFS2 would dereference an error value, plus three cosmetic / refactoring patches. - Daniel DeFreez has a patch to fix two glock reference count problems, where GFS2 was not properly "uninitializing" its glock holder on error paths. - Denys Vlasenko has a patch to change a function to not be inlined, thus reducing the memory footprint of the GFS2 module" * tag 'gfs2-4.7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: GFS2: Refactor gfs2_remove_from_journal GFS2: Remove allocation parms from gfs2_rbm_find gfs2: use inode_lock/unlock instead of accessing i_mutex directly GFS2: Add calls to gfs2_holder_uninit in two error handlers GFS2: Don't dereference inode in gfs2_inode_lookup until it's valid GFS2: fs/gfs2/glock.c: Deinline do_error, save 1856 bytes gfs2: Use gfs2 wrapper to sync inode before calling generic_file_splice_read() GFS2: Get rid of dead code in inode_go_demote_ok GFS2: ignore unlock failures after withdraw
2016-05-06GFS2: Refactor gfs2_remove_from_journalBob Peterson
This patch makes two simple changes to function gfs2_remove_from_journal. First, it removes the parameter that specifies the transaction. Since it's always passed in as current->journal_info, we might as well set that in the function rather than passing it in. Second, it changes the meta parameter to use an enum to make the code more clear. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-18gfs2: Extended attribute readahead optimizationAndreas Gruenbacher
Instead of submitting a READ_SYNC bio for the inode and a READA bio for the inode's extended attributes through submit_bh, submit a single READ_SYNC bio for both through submit_bio when possible. This can be more efficient on some kinds of block devices. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2015-11-16gfs2: Extended attribute readaheadAndreas Gruenbacher
When gfs2 allocates an inode and its extended attribute block next to each other at inode create time, the inode's directory entry indicates that in de_rahead. In that case, we can readahead the extended attribute block when we read in the inode. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2015-09-03GFS2: Move glock superblock pointer to field gl_nameBob Peterson
What uniquely identifies a glock in the glock hash table is not gl_name, but gl_name and its superblock pointer. This patch makes the gl_name field correspond to a unique glock identifier. That will allow us to simplify hashing with a future patch, since the hash algorithm can then take the gl_name and hash its components in one operation. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com>
2014-06-04mm: non-atomically mark page accessed during page cache allocation where ↵Mel Gorman
possible aops->write_begin may allocate a new page and make it visible only to have mark_page_accessed called almost immediately after. Once the page is visible the atomic operations are necessary which is noticable overhead when writing to an in-memory filesystem like tmpfs but should also be noticable with fast storage. The objective of the patch is to initialse the accessed information with non-atomic operations before the page is visible. The bulk of filesystems directly or indirectly use grab_cache_page_write_begin or find_or_create_page for the initial allocation of a page cache page. This patch adds an init_page_accessed() helper which behaves like the first call to mark_page_accessed() but may called before the page is visible and can be done non-atomically. The primary APIs of concern in this care are the following and are used by most filesystems. find_get_page find_lock_page find_or_create_page grab_cache_page_nowait grab_cache_page_write_begin All of them are very similar in detail to the patch creates a core helper pagecache_get_page() which takes a flags parameter that affects its behavior such as whether the page should be marked accessed or not. Then old API is preserved but is basically a thin wrapper around this core function. Each of the filesystems are then updated to avoid calling mark_page_accessed when it is known that the VM interfaces have already done the job. There is a slight snag in that the timing of the mark_page_accessed() has now changed so in rare cases it's possible a page gets to the end of the LRU as PageReferenced where as previously it might have been repromoted. This is expected to be rare but it's worth the filesystem people thinking about it in case they see a problem with the timing change. It is also the case that some filesystems may be marking pages accessed that previously did not but it makes sense that filesystems have consistent behaviour in this regard. The test case used to evaulate this is a simple dd of a large file done multiple times with the file deleted on each iterations. The size of the file is 1/10th physical memory to avoid dirty page balancing. In the async case it will be possible that the workload completes without even hitting the disk and will have variable results but highlight the impact of mark_page_accessed for async IO. The sync results are expected to be more stable. The exception is tmpfs where the normal case is for the "IO" to not hit the disk. The test machine was single socket and UMA to avoid any scheduling or NUMA artifacts. Throughput and wall times are presented for sync IO, only wall times are shown for async as the granularity reported by dd and the variability is unsuitable for comparison. As async results were variable do to writback timings, I'm only reporting the maximum figures. The sync results were stable enough to make the mean and stddev uninteresting. The performance results are reported based on a run with no profiling. Profile data is based on a separate run with oprofile running. async dd 3.15.0-rc3 3.15.0-rc3 vanilla accessed-v2 ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%) tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%) btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%) ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%) xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%) The XFS figure is a bit strange as it managed to avoid a worst case by sheer luck but the average figures looked reasonable. samples percentage ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed [akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer] Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-31GFS2: Fix address space from page functionSteven Whitehouse
Now that rgrps use the address space which is part of the super block, we need to update gfs2_mapping2sbd() to take account of that. The only way to do that easily is to use a different set of address_space_operations for rgrps. Reported-by: Abhi Das <adas@redhat.com> Tested-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-02-24GFS2: Move log buffer accounting to transactionSteven Whitehouse
Now we have a master transaction into which other transactions are merged, the accounting can be done using this master transaction. We no longer require the superblock fields which were being used for this function. In addition, this allows for a clean up in calc_reserved() making it rather easier understand. Also, by reducing the number of variables used to track the buffers being added and removed from the journal, a number of error checks are now no longer required. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-01-03GFS2: Use only a single address space for rgrpsSteven Whitehouse
Prior to this patch, GFS2 had one address space for each rgrp, stored in the glock. This patch changes them to use a single address space in the super block. This therefore saves (sizeof(struct address_space) * nr_of_rgrps) bytes of memory and for large filesystems, that can be significant. It would be nice to be able to do something similar and merge the inode metadata address space into the same global address space. However, that is rather more complicated as the on-disk location doesn't have a 1:1 mapping with the inodes in general. So while it could be done, it will be a more complicated operation as it requires changing a lot more code paths. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-12-13GFS2: Fix slab memory leak in gfs2_bufdataBob Peterson
This patch fixes a slab memory leak that sometimes can occur for files with a very short lifespan. The problem occurs when a dinode is deleted before it has gotten to the journal properly. In the leak scenario, the bd object is pinned for journal committment (queued to the metadata buffers queue: sd_log_le_buf) but is subsequently unpinned and dequeued before it finds its way to the ail or the revoke queue. In this rare circumstance, the bd object needs to be freed from slab memory, or it is forgotten. We have to be very careful how we do it, though, because multiple processes can call gfs2_remove_from_journal. In order to avoid double-frees, only the process that does the unpinning is allowed to free the bd. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-08-19GFS2: Move gfs2_sync_meta to lops.cSteven Whitehouse
Since gfs2_sync_meta() is only called from a single file, lets move it to lops.c where it is used, and mark it static. At the same time, we can clean up the meta_io.h header too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-06-19GFS2: aggressively issue revokes in gfs2_log_flushBenjamin Marzinski
This patch looks at all the outstanding blocks in all the transactions on the log, and moves the completed ones to the ail2 list. Then it issues revokes for these blocks. This will hopefully speed things up in situations where there is a lot of contention for glocks, especially if they are acquired serially. revoke_lo_before_commit will issue at most one log block's full of these preemptive revokes. The amount of reserved log space that gfs2_log_reserve() ignores has been incremented to allow for this extra block. This patch also consolidates the common revoke instructions into one function, gfs2_add_revoke(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-04-08GFS2: replace gfs2_ail structure with gfs2_transBenjamin Marzinski
In order to allow transactions and log flushes to happen at the same time, gfs2 needs to move the transaction accounting and active items list code into the gfs2_trans structure. As a first step toward this, this patch removes the gfs2_ail structure, and handles the active items list in the gfs_trans structure. This keeps gfs2 from allocating an ail structure on log flushes, and gives us a struture that can later be used to store the transaction accounting outside of the gfs2 superblock structure. With this patch, at the end of a transaction, gfs2 will add the gfs2_trans structure to the superblock if there is not one already. This structure now has the active items fields that were previously in gfs2_ail. This is not necessary in the case where the transaction was simply used to add revokes, since these are never written outside of the journal, and thus, don't need an active items list. Also, in order to make sure that the transaction structure is not removed while it's still in use by gfs2_trans_end, unlocking the sd_log_flush_lock has to happen slightly later in ending the transaction. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-01-29GFS2: Merge gfs2_attach_bufdata() into trans.cSteven Whitehouse
The locking in gfs2_attach_bufdata() was type specific (data/meta) which made the function rather confusing. This patch moves the core of gfs2_attach_bufdata() into trans.c renaming it gfs2_alloc_bufdata() and moving the locking into gfs2_trans_add_data()/gfs2_trans_add_meta() As a result all of the locking related to adding data and metadata to the journal is now in these two functions. This should help to clarify what is going on, and give us some opportunities to simplify in some cases. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-08-04gfs2: nuke pdflush from commentsArtem Bityutskiy
The pdflush thread is long gone, so this patch removes references to pdflush from gfs comments. Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-28GFS2: Fixing double brelse'ing bh allocated in gfs2_meta_read when EIO occursMasatake YAMATO
This patch fixes buffer_head double free in following code path: gfs2_block_map => gfs2_meta_inode_buffer => gfs2_meta_indirect_buffer => gfs2_meta_read => release_metapath gfs2_block_map calls gfs2_meta_inode_buffer with &mp.mp_bh[0] as an argument. mp.mp_bh are filled with zero at the beginning of gfs2_block_map. If gfs2_meta_inode_buffer returns non-zero value, gfs2_block_map calls release_metapath to free buffers chained to mp.mp_bh. release_metapath checks each slot of mp.mp_bh[i] and free(with brelse) unless the slot is filled with NULL. &mp.mp_bh[0] passed to gfs2_meta_inode_buffer is filled at gfs2_meta_read. gfs2_meta_read is filled a buffer allocated with gfs2_getbuf even if EIO occurs. When EIO occurs, the allocated buffer is brelse'ed though the pointer(wrong poiner) points the brelse'ed is passed back to caller via an argument bhp. gfs2_meta_indirect_buffer, the caller also pass the wrong pointer to its caller with EIO. Finally gfs2_block_map gets both EIO and &mp.mp_bh[0] filled with the wrong pointer. release_metapath calls brelse again on the wrong pointer. Signed-off-by: Masatake YAMATO <yamato@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-05-11GFS2: Eliminate unused "new" parameter to gfs2_meta_indirect_bufferBob Peterson
It turns out that the "new" parameter to function gfs2_meta_indirect_buffer was always being passed in as zero. Therefore, this patch eliminates it and simplifies the function. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-05-02GFS2: eliminate log elements and simplifyBob Peterson
This patch eliminates the gfs2_log_element data structure and rolls its two components into the gfs2_bufdata. This makes the code easier to understand and makes it easier to migrate to a rbtree to keep the list sorted. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24GFS2: Remove bd_list_trSteven Whitehouse
This is another clean up in the logging code. This per-transaction list was largely unused. Its main function was to ensure that the number of buffers in a transaction was correct, however that counter was only used to check the number of buffers in the bd_list_tr, plus an assert at the end of each transaction. With the assert now changed to use the calculated buffer counts, we can remove both bd_list_tr and its associated counter. This should make the code easier to understand as well as shrinking a couple of structures. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-08GFS2: Fix up REQ flagsSteven Whitehouse
Christoph has split up REQ_PRIO from REQ_META. That means that we can drop REQ_PRIO from places where is it not needed. I'm not at all sure that the combination WRITE_FLUSH_FUA | REQ_PRIO makes any kind of sense, anyway. In addition, I've added REQ_META to one place in the code where it was missing. REQ_PRIO has been left for read/writes triggered by glock acquisition and writeback only. We can adjust it again if required, but these are the most important points from a performance perspective. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@infradead.org>
2011-08-23block: separate priority boosting from REQ_METAChristoph Hellwig
Add a new REQ_PRIO to let requests preempt others in the cfq I/O schedule, and lave REQ_META purely for marking requests as metadata in blktrace. All existing callers of REQ_META except for XFS are updated to also set REQ_PRIO for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-20GFS2: Improve tracing support (adds two flags)Steven Whitehouse
This adds support for two new flags. One keeps track of whether the glock is on the LRU list or not. The other isn't really a flag as such, but an indication of whether the glock has an attached object or not. This indication is reported without any locking, which is ok since we do not dereference the object pointer but merely report whether it is NULL or not. Also, this fixes one place where a tracepoint was missing, which was at the point we remove deallocated blocks from the journal. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-24Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
2011-03-14GFS2: Update to AIL list lockingSteven Whitehouse
The previous patch missed a couple of places where the AIL list needed locking, so this fixes up those places, plus a comment is corrected too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Chinner <dchinner@redhat.com>
2011-03-10block: kill off REQ_UNPLUGJens Axboe
With the plugging now being explicitly controlled by the submitter, callers need not pass down unplugging hints to the block layer. If they want to unplug, it's because they manually plugged on their own - in which case, they should just unplug at will. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>