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path: root/drivers/md/bitmap.c
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2015-05-21md/bitmap: remove rcu annotation from pointer arithmetic.NeilBrown
Evaluating "&mddev->disks" is simple pointer arithmetic, so it does not need 'rcu' annotations - no dereferencing is happening. Also enhance the comment to explain that 'rdev' in that case is not actually a pointer to an rdev. Reported-by: Patrick Marlier <patrick.marlier@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22md-cluster: re-add capabilitiesGoldwyn Rodrigues
When "re-add" is writted to /sys/block/mdXX/md/dev-YYY/state, the clustered md: 1. Sends RE_ADD message with the desc_nr. Nodes receiving the message clear the Faulty bit in their respective rdev->flags. 2. The node initiating re-add, gathers the bitmaps of all nodes and copies them into the local bitmap. It does not clear the bitmap from which it is copying. 3. Initiating node schedules a md recovery to sync the devices. Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-25md: Fix bitmap offset calculationsGoldwyn Rodrigues
The calculations of bitmap offset is incorrect with respect to bits to bytes conversion. Also, remove an irrelevant duplicate message. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-04md/bitmap: use sector_div for sector_t divisionsStephen Rothwell
neilb: modified to not corrupt ->resync_max_sectors. sector_div usage fixed by Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-04md/bitmap: fix incorrect DIV_ROUND_UP usage.NeilBrown
DIV_ROUTND_UP doesn't work on "long long", - and it should be sector_t anyway. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-23Copy set bits from another slotGoldwyn Rodrigues
bitmap_copy_from_slot reads the bitmap from the slot mentioned. It then copies the set bits to the node local bitmap. This is helper function for the resync operation on node failure. bitmap_set_memory_bits() currently assumes it is only run at startup and that they bitmap is currently empty. So if it finds that a region is already marked as dirty, it won't mark it dirty again. Change bitmap_set_memory_bits() to always set the NEEDED_MASK bit if 'needed' is set. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23bitmap_create returns bitmap pointerGoldwyn Rodrigues
This is done to have multiple bitmaps open at the same time. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Use separate bitmaps for each nodes in the clusterGoldwyn Rodrigues
On-disk format: 0 4k 8k 12k ------------------------------------------------------------------- | idle | md super | bm super [0] + bits | | bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] | | bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits | | bm bits [3, contd] | | | Bitmap super has a field nodes, which defines the maximum number of nodes the device can use. While reading the bitmap super, if the cluster finds out that the number of nodes is > 0: 1. Requests the md-cluster module. 2. Calls md_cluster_ops->join(), which sets up clustering such as joining DLM lockspace. Since the first time, the first bitmap is read. After the call to the cluster_setup, the bitmap offset is adjusted and the superblock is re-read. This also ensures the bitmap is read the bitmap lock (when bitmap lock is introduced in later patches) Questions: 1. cluster name is repeated in all bitmap supers. Is that okay? Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Add node recovery callbacksGoldwyn Rodrigues
DLM offers callbacks when a node fails and the lock remastery is performed: 1. recover_prep: called when DLM discovers a node is down 2. recover_slot: called when DLM identifies the node and recovery can start 3. recover_done: called when all nodes have completed recover_slot recover_slot() and recover_done() are also called when the node joins initially in order to inform the node with its slot number. These slot numbers start from one, so we deduct one to make it start with zero which the cluster-md code uses. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23Introduce md_cluster_infoGoldwyn Rodrigues
md_cluster_info stores the cluster information in the MD device. The join() is called when mddev detects it is a clustered device. The main responsibilities are: 1. Setup a DLM lockspace 2. Setup all initial locks such as super block locks and bitmap lock (will come later) The leave() clears up the lockspace and all the locks held. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-06md: remove mddev_lock() from md_attr_show()NeilBrown
Most attributes can be read safely without any locking. A race might lead to a slightly out-dated value, but nothing wrong. We already have locking in some places where needed. All that remains is can_clear_show(), behind_writes_used_show() and action_show() which are easily fixed. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-06md/bitmap: protect clearing of ->bitmap by mddev->lockNeilBrown
This makes it safe to inspect the struct while holding only the spinlock. Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-02md/bitmap: fix a might_sleep() warning.NeilBrown
commit 8eb23b9f35aae413140d3fda766a98092c21e9b0 sched: Debug nested sleeps causes false-positive warnings in RAID5 code. This annotation removes them and adds a comment explaining why there is no real problem. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-09md/bitmap: always wait for writes on unplug.NeilBrown
If two threads call bitmap_unplug at the same time, then one might schedule all the writes, and the other might decide that it doesn't need to wait. But really it does. It rarely hurts to wait when it isn't absolutely necessary, and the current code doesn't really focus on 'absolutely necessary' anyway. So just wait always. This can potentially lead to data corruption if a crash happens at an awkward time and data was written before the bitmap was updated. It is very unlikely, but this should go to -stable just to be safe. Appropriate for any -stable. Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@vger.kernel.org (please delay until 3.18 is released)
2014-05-29md/bitmap: remove confusing code from filemap_get_page.NeilBrown
file_page_index(store, 0) is *always* 0. This is because the bitmap sb, at 256 bytes, is *always* less than one page. So subtracting it has no effect and the code should be removed. Reported-by: Goldwyn Rodrigues <rgoldwyn@suse.de> Signed-off-by: NeilBrown <neilb@suse.de>
2014-04-09md/bitmap: don't abuse i_writecount for bitmap files.NeilBrown
md bitmap code currently tries to use i_writecount to stop any other process from writing to out bitmap file. But that is really an abuse and has bit-rotted so locking is all wrong. So discard that - root should be allowed to shoot self in foot. Still use it in a much less intrusive way to stop the same file being used as bitmap on two different array, and apply other checks to ensure the file is at least vaguely usable for bitmap storage (is regular, is open for write. Support for ->bmap is already checked elsewhere). Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: NeilBrown <neilb@suse.de>
2013-12-11kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordinglyTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Neil Brown <neilb@suse.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: clean up sysfs_get_dirent()Tejun Heo
The pre-existing sysfs interfaces which take explicit namespace argument are weird in that they place the optional @ns in front of @name which is contrary to the established convention. For example, we end up forcing vast majority of sysfs_get_dirent() users to do sysfs_get_dirent(parent, NULL, name), which is silly and error-prone especially as @ns and @name may be interchanged without causing compilation warning. This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the positions of @name and @ns, and sysfs_get_dirent() is now a wrapper around sysfs_get_dirent_ns(). This makes confusions a lot less likely. There are other interfaces which take @ns before @name. They'll be updated by following patches. This patch doesn't introduce any functional changes. v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol error on module builds. Reported by build test robot. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-14md: replace strict_strto*() with kstrto*()Jingoo Han
The usage of strict_strtoul() is not preferred, because strict_strtoul() is obsolete. Thus, kstrtoul() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24md: use set_bit_le and clear_bit_leAkinobu Mita
The value returned by test_and_set_bit_le() drivers/md/bitmap.c is not used. So just use set_bit_le(). The same goes for test_and_clear_bit_le(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11md/bitmap:Don't use IS_ERR to judge alloc_page().Jianpeng Ma
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11raid: replace list_for_each_continue_rcu with new interfaceMichael Wang
This patch replaces list_for_each_continue_rcu() with list_for_each_entry_continue_rcu() to save a few lines of code and allow removing list_for_each_continue_rcu(). Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02md/raid1: submit IO from originating thread instead of md thread.NeilBrown
queuing writes to the md thread means that all requests go through the one processor which may not be able to keep up with very high request rates. So use the plugging infrastructure to submit all requests on unplug. If a 'schedule' is needed, we fall back on the old approach of handing the requests to the thread for it to handle. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: record the space available for the bitmap in the superblock.NeilBrown
Now that bitmaps can grow and shrink it is best if we record how much space is available. This means that when we reduce the size of the bitmap we won't "lose" the space for late when we might want to increase the size of the bitmap again. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: make sure reshape request are reflected in superblock.NeilBrown
As a reshape may change the sync_size and/or chunk_size, we need to update these whenever we write out the bitmap superblock. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: add bitmap_resize function to allow bitmap resizing.NeilBrown
This function will allocate the new data structures and copy bits across from old to new, allowing for the possibility that the chunksize has changed. Use the same function for performing the initial allocation of the structures. This improves test coverage. When bitmap_resize is used to resize an existing bitmap, it only copies '1' bits in, not '0' bits. So when allocating the bitmap, ensure everything is initialised to ZERO. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: use DIV_ROUND_UP instead of open-codeNeilBrown
Also take the opportunity to simplify CHUNK_BLOCK_RATIO. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'NeilBrown
The new "struct bitmap_counts" contains all the fields that are related to counting the number of active writes in each bitmap chunk. Having this separate will make it easier to change the chunksize or overall size of a bitmap atomically. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: make bitmap bitops atomic.NeilBrown
This allows us to remove spinlock protection which is more heavy-weight than simple atomics. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: make _page_attr bitops atomic.NeilBrown
Using e.g. set_bit instead of __set_bit and using test_and_clear_bit allow us to remove some locking and contract other locked ranges. It is rare that we set or clear a lot of these bits, so gain should outweigh any cost. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: merge bitmap_file_unmap and bitmap_file_put.NeilBrown
There functions really do one thing together: release the 'bitmap_storage'. So make them just one function. Since we removed the locking (previous patch), we don't need to zero any fields before freeing them, so it all becomes a bit simpler. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: remove async freeing of bitmap file.NeilBrown
There is no real value in freeing things the moment there is an error. It is just as good to free the bitmap file and pages when the bitmap is explicitly removed (and replaced?) or at shutdown. With this gone, the bitmap will only disappear when the array is quiescent, so we can remove some locking. As the 'filemap' doesn't disappear now, include extra checks before trying to write any of it out. Also remove the check for "has it disappeared" in bitmap_daemon_write(). Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: convert some spin_lock_irqsave to spin_lock_irqNeilBrown
All of these sites can only be called from process context with irqs enabled, so using irqsave/irqrestore just adds noise. Remove it. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: use set_bit, test_bit, etc for operation on bitmap->flags.NeilBrown
We currently use '&' and '|' which isn't the norm in the kernel and doesn't allow easy atomicity. So change to bit numbers and {set,clear,test}_bit. This allows us to remove a spinlock/unlock (which was dubious anyway) and some other simplifications. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: remove single-bit manipulation on sb->stateNeilBrown
Just do single-bit manipulations on bitmap->flags and copy whole value between that and sb->state. This will allow next patch which changes how bit manipulations are performed on bitmap->flags. This does result in BITMAP_STALE not being set in sb by bitmap_read_sb, however as the setting is determined by other information in the 'sb' we do not lose information this way. Normally, bitmap_load will be called shortly which will clear BITMAP_STALE anyway. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: remove bitmap_mask_stateNeilBrown
This function isn't really needed. It sets or clears a flag in both bitmap->flags and sb->state. However both times it is called, bitmap_update_sb is called soon afterwards which copies bitmap->flags to sb->state. So just make changes to bitmap->flags, and open-code those rather than hiding in a function. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: move storage allocation from bitmap_load to bitmap_create.NeilBrown
We should allocate memory for the storage-bitmap at create-time, not load time. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: separate bitmap file allocation to its own function.NeilBrown
This will allow allocation before swapping in a new bitmap. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: store bytes in file rather than just in last page.NeilBrown
This number is more generally useful, and bytes-in-last-page is easily extracted from it. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: move some fields of 'struct bitmap' into a 'storage' substruct.NeilBrown
This new 'struct bitmap_storage' reflects the external storage of the bitmap. Having this clearly defined will make it easier to change the storage used while the array is active. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: change *_page_attr() to take a page number, not a page.NeilBrown
Most often we have the page number, not the page. And that is what the *_page_attr() functions really want. So change the arguments to take that number. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: centralise allocation of bitmap file pages.NeilBrown
Instead of allocating pages in read_sb_page, read_page and bitmap_read_sb, allocate them all in bitmap_init_from disk. Also replace the hack of calling "attach_page_buffers(page, NULL)" to ensure that free_buffer() won't complain, by putting a test for PagePrivate in free_buffer(). Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: allow a bitmap with no backing storage.NeilBrown
An md bitmap comprises two parts - internal counting of active writes per 'chunk'. - external storage of whether there are any active writes on each chunk The second requires the first, but the first doesn't require the second. Not having backing storage means that the bitmap cannot expedite resync after a crash, but it still allows us to expedite the recovery of a recently-removed device. So: allow a bitmap to exist even if there is no backing device. In that case we default to 128M chunks. A particular value of this is that we can remove and re-add a bitmap (possibly of a different granularity) on a degraded array, and not lose the information needed to fast-recover the missing device. We don't actually activate these bitmaps yet - that will come in a later patch. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: add new 'space' attribute for bitmaps.NeilBrown
If we are to allow bitmaps to be resized when the array is resized, we need to know how much space there is. So create an attribute to store this information and set appropriate defaults. It can be set more precisely via sysfs, or future metadata extensions may allow it to be recorded. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22md/bitmap: disentangle two different 'pending' flags.NeilBrown
There are two different 'pending' concepts in the handling of the write intent bitmap. Firstly, a 'page' from the bitmap (which container PAGE_SIZE*8 bits) may have changes (bits cleared) that should be written in due course. There is no hurry for these and the page will transition from PENDING to NEEDWRITE and will then be written, though if it ever becomes DIRTY it will be written much sooner and PENDING will be cleared. Secondly, a page of counters - which contains PAGE_SIZE/2 counters, one for each bit, can usefully have a 'pending' flag which indicates if any of the counters are low (2 or 1) and ready to be processed by bitmap_daemon_work(). If this flag is clear we can skip the whole page. These two concepts are currently combined in the bitmap-file flag. This causes a tighter connection between the counters and the bitmap file than I would like - as I want to add some flexibility to the bitmap file. So introduce a new flag with the page-of-counters, and rewrite bitmap_daemon_work() so that it handles the two different 'pending' concepts separately. This also allows us to clear BITMAP_PAGE_PENDING when we write out a dirty page, which may occasionally reduce the number of times we write a page. Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-04md/bitmap: fix calculation of 'chunks' - missing shift.NeilBrown
commit 61a0d80c "md/bitmap: discard CHUNK_BLOCK_SHIFT macro" replaced CHUNK_BLOCK_RATIO() by the same text that was replacing CHUNK_BLOCK_SHIFT() - which is clearly wrong. The result is that 'chunks' is often too small by 1, which can sometimes result in a crash (not sure how). So use the correct replacement, and get rid of CHUNK_BLOCK_RATIO which is no longe used. Reported-by: Karl Newman <siliconfiend@gmail.com> Tested-by: Karl Newman <siliconfiend@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-12md/bitmap: prevent bitmap_daemon_work running while initialising bitmapNeilBrown
If a bitmap is added while the array is active, it is possible for bitmap_daemon_work to run while the bitmap is being initialised. This is particularly a problem if bitmap_daemon_work sees bitmap->filemap as non-NULL before it has been filled in properly. So hold bitmap_info.mutex while filling in ->filemap to prevent problems. This patch is suitable for any -stable kernel, though it might not apply cleanly before about 3.1. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-12MD: Bitmap version cleanup.Andrei Warkentin
bitmap_new_disk_sb() would still create V3 bitmap superblock with host-endian layout. Perhaps I'm confused, but shouldn't bitmap_new_disk_sb() be creating a V4 bitmap superblock instead, that is portable, as per comment in bitmap.h? Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-22Merge tag 'md-3.4' of git://neil.brown.name/mdLinus Torvalds
Pull md updates for 3.4 from Neil Brown: "Mostly tidying up code in preparation for some bigger changes next time. A few bug fixes tagged for -stable. Main functionality change is that some RAID10 arrays can now grow to use extra space that may have been made available on the individual devices." Fixed up trivial conflicts with the k[un]map_atomic() cleanups in drivers/md/bitmap.c. * tag 'md-3.4' of git://neil.brown.name/md: (22 commits) md: Add judgement bb->unacked_exist in function md_ack_all_badblocks(). md: fix clearing of the 'changed' flags for the bad blocks list. md/bitmap: discard CHUNK_BLOCK_SHIFT macro md/bitmap: remove unnecessary indirection when allocating. md/bitmap: remove some pointless locking. md/bitmap: change a 'goto' to a normal 'if' construct. md/bitmap: move printing of bitmap status to bitmap.c md/bitmap: remove some unused noise from bitmap.h md/raid10 - support resizing some RAID10 arrays. md/raid1: handle merge_bvec_fn in member devices. md/raid10: handle merge_bvec_fn in member devices. md: add proper merge_bvec handling to RAID0 and Linear. md: tidy up rdev_for_each usage. md/raid1,raid10: avoid deadlock during resync/recovery. md/bitmap: ensure to load bitmap when creating via sysfs. md: don't set md arrays to readonly on shutdown. md: allow re-add to failed arrays. md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read(). md: Use existed macros instead of numbers md/raid5: removed unused 'added_devices' variable. ...