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path: root/drivers/md/bitmap.c
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* Fix problem with waiting while holding rcu read lock in md/bitmap.cNeilBrown2008-08-31
| | | | | | | | | | | | | | | | | | A recent patch to protect the rdev list with rcu locking leaves us with a problem because we can sleep on memalloc while holding the rcu lock. The rcu lock is only needed while walking the linked list as uninteresting devices (failed or spares) can be removed at any time. So only take the rcu lock while actually walking the linked list. Take a refcount on the rdev during the time when we drop the lock and do the memalloc to start IO. When we return to the locked code, all the interesting devices on the list will not have moved, so we can simply use list_for_each_continue_rcu to pick up where we left off. Signed-off-by: NeilBrown <neilb@suse.de>
* md: the bitmap code needs to use blk_plug_device_unlocked()Jens Axboe2008-08-01
| | | | | | | It doesn't hold the queue lock, so it's both racey on the queue flags and thus spews a warning. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* md: Protect access to mddev->disks list using RCUNeilBrown2008-07-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All modifications and most access to the mddev->disks list are made under the reconfig_mutex lock. However there are three places where the list is walked without any locking. If a reconfig happens at this time, havoc (and oops) can ensue. So use RCU to protect these accesses: - wrap them in rcu_read_{,un}lock() - use list_for_each_entry_rcu - add to the list with list_add_rcu - delete from the list with list_del_rcu - delay the 'free' with call_rcu rather than schedule_work Note that export_rdev did a list_del_init on this list. In almost all cases the entry was not in the list anymore so it was a no-op and so safe. It is no longer safe as after list_del_rcu we may not touch the list_head. An audit shows that export_rdev is called: - after unbind_rdev_from_array, in which case the delete has already been done, - after bind_rdev_to_array fails, in which case the delete isn't needed. - before the device has been put on a list at all (e.g. in add_new_disk where reading the superblock fails). - and in autorun devices after a failure when the device is on a different list. So remove the list_del_init call from export_rdev, and add it back immediately before the called to export_rdev for that last case. Note also that ->same_set is sometimes used for lists other than mddev->list (e.g. candidates). In these cases rcu is not needed. Signed-off-by: NeilBrown <neilb@suse.de>
* md: Turn rdev->sb_offset into a sector-based quantity.Andre Noll2008-07-11
| | | | | | | Rename it to sb_start to make sure all users have been converted. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Neil Brown <neilb@suse.de>
* Improve setting of "events_cleared" for write-intent bitmaps.Neil Brown2008-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an array is degraded, bits in the write-intent bitmap are not cleared, so that if the missing device is re-added, it can be synced by only updated those parts of the device that have changed since it was removed. The enable this a 'events_cleared' value is stored. It is the event counter for the array the last time that any bits were cleared. Sometimes - if a device disappears from an array while it is 'clean' - the events_cleared value gets updated incorrectly (there are subtle ordering issues between updateing events in the main metadata and the bitmap metadata) resulting in the missing device appearing to require a full resync when it is re-added. With this patch, we update events_cleared precisely when we are about to clear a bit in the bitmap. We record events_cleared when we clear the bit internally, and copy that to the superblock which is written out before the bit on storage. This makes it more "obviously correct". We also need to update events_cleared when the event_count is going backwards (as happens on a dirty->clean transition of a non-degraded array). Thanks to Mike Snitzer for identifying this problem and testing early "fixes". Cc: "Mike Snitzer" <snitzer@gmail.com> Signed-off-by: Neil Brown <neilb@suse.de>
* md: kill file_path wrapperChristoph Hellwig2008-05-24
| | | | | | | | | Kill the trivial and rather pointless file_path wrapper around d_path. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: reduce CPU wastage on idle md array with a write-intent bitmapNeilBrown2008-03-10
| | | | | | | | | | | | | | | | Recent patch titled Reduce CPU wastage on idle md array with a write-intent bitmap. would sometimes leave the array with dirty bitmap bits that stay dirty. A subsequent write would sort things out so it isn't a big problem, but should be fixed nonetheless. We need to make sure that when the bitmap becomes not "allclean", the daemon_sleep really does get set to a sensible value. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: reduce CPU wastage on idle md array with a write-intent bitmapNeilBrown2008-03-04
| | | | | | | | | | | | | On an md array with a write-intent bitmap, a thread wakes up every few seconds and scans the bitmap looking for work to do. If the array is idle, there will be no work to do, but a lot of scanning is done to discover this. So cache the fact that the bitmap is completely clean, and avoid scanning the whole bitmap when the cache is known to be clean. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* d_path: Make d_path() use a struct pathJan Blunck2008-02-15
| | | | | | | | | | | | | | | | d_path() is used on a <dentry,vfsmount> pair. Lets use a struct path to reflect this. [akpm@linux-foundation.org: fix build in mm/memory.c] Signed-off-by: Jan Blunck <jblunck@suse.de> Acked-by: Bryan Wu <bryan.wu@analog.com> Acked-by: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: change ITERATE_RDEV to rdev_for_eachNeilBrown2008-02-06
| | | | | | | | | As this is more in line with common practice in the kernel. Also swap the args around to be more like list_for_each. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: Update md bitmap during resync.NeilBrown2008-02-06
| | | | | | | | | | | | | | | | | | | | Currently an md array with a write-intent bitmap does not updated that bitmap to reflect successful partial resync. Rather the entire bitmap is updated when the resync completes. This is because there is no guarentee that resync requests will complete in order, and tracking each request individually is unnecessarily burdensome. However there is value in regularly updating the bitmap, so add code to periodically pause while all pending sync requests complete, then update the bitmap. Doing this only every few seconds (the same as the bitmap update time) does not notciably affect resync performance. [snitzer@gmail.com: export bitmap_cond_end_sync] Signed-off-by: Neil Brown <neilb@suse.de> Cc: "Mike Snitzer" <snitzer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add UNPLUG traces to all appropriate placesAlan D. Brunelle2007-11-09
| | | | | | | | Added blk_unplug interface, allowing all invocations of unplugs to result in a generated blktrace UNPLUG. Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* md: fix an unsigned compare to allow creation of bitmaps with v1.0 metadataNeilBrown2007-10-23
| | | | | | | | | | As page->index is unsigned, this all becomes an unsigned comparison, which almost always returns an error. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Stable <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: change bitmap_unplug and others to void functionsNeilBrown2007-07-17
| | | | | | | | | | | | | | | | | | | | | | bitmap_unplug only ever returns 0, so it may as well be void. Two callers try to print a message if it returns non-zero, but that message is already printed by bitmap_file_kick. write_page returns an error which is not consistently checked. It always causes BITMAP_WRITE_ERROR to be set on an error, and that can more conveniently be checked. When the return of write_page is checked, an error causes bitmap_file_kick to be called - so move that call into write_page - and protect against recursive calls into bitmap_file_kick. bitmap_update_sb returns an error that is never checked. So make these 'void' and be consistent about checking the bit. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: check that internal bitmap does not overlap other dataNeilBrown2007-07-17
| | | | | | | | | | | | | We current completely trust user-space to set up metadata describing an consistant array. In particlar, that the metadata, data, and bitmap do not overlap. But userspace can be buggy, and it is better to report an error than corrupt data. So put in some appropriate checks. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: don't write more than is required of the last page of a bitmapNeilBrown2007-05-23
| | | | | | | | | | | | | It is possible that real data or metadata follows the bitmap without full page alignment. So limit the last write to be only the required number of bytes, rounded up to the hard sector size of the device. Signed-off-by: Neil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove do_sync_file_range()Mark Fasheh2007-05-08
| | | | | | | | | | Remove do_sync_file_range() and convert callers to just use do_sync_mapping_range(). Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] md: fix calculation for size of filemap_attr array in md/bitmapNeil Brown2007-04-12
| | | | | | | | | | | If 'num_pages' were ever 1 more than a multiple of 8 (32bit platforms) or of 16 (64 bit platforms). filemap_attr would be allocated one 'unsigned long' shorter than required. We need a round-up in there. Signed-off-by: Neil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] remove invalidate_inode_pages()Andrew Morton2007-02-11
| | | | | | | | | | | Convert all calls to invalidate_inode_pages() into open-coded calls to invalidate_mapping_pages(). Leave the invalidate_inode_pages() wrapper in place for now, marked as deprecated. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] md: avoid possible BUG_ON in md bitmap handlingNeil Brown2007-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | md/bitmap tracks how many active write requests are pending on blocks associated with each bit in the bitmap, so that it knows when it can clear the bit (when count hits zero). The counter has 14 bits of space, so if there are ever more than 16383, we cannot cope. Currently the code just calles BUG_ON as "all" drivers have request queue limits much smaller than this. However is seems that some don't. Apparently some multipath configurations can allow more than 16383 concurrent write requests. So, in this unlikely situation, instead of calling BUG_ON we now wait for the count to drop down a bit. This requires a new wait_queue_head, some waiting code, and a wakeup call. Tested by limiting the counter to 20 instead of 16383 (writes go a lot slower in that case...). Signed-off-by: Neil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] md: avoid reading past the end of a bitmap fileNeilBrown2007-01-26
| | | | | | | | | | | | | | | In most cases we check the size of the bitmap file before reading data from it. However when reading the superblock, we always read the first PAGE_SIZE bytes, which might not always be appropriate. So limit that read to the size of the file if appropriate. Also, we get the count of available bytes wrong in one place, so that too can read past the end of the file. Cc: "yang yin" <yinyang801120@gmail.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] struct path: convert mdJosef Sipek2006-12-08
| | | | | | Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: endian annotations for the bitmap superblockNeilBrown2006-10-21
| | | | | | | | And a couple of bug fixes found by sparse. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: use BUILD_BUG_ONAlexey Dobriyan2006-10-11
| | | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: use ffz instead of find_first_set to convert multiplier to shiftPaul Clements2006-10-03
| | | | | | | | | | | | find_first_set doesn't find the least-significant bit on bigendian machines, so it is really wrong to use it. ffs is closer, but takes an 'int' and we have a 'unsigned long'. So use ffz(~X) to convert a chunksize into a chunkshift. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: new sysfs interface for setting bits in the write-intent-bitmapPaul Clements2006-10-03
| | | | | | | | | | | | | | | | | | | | | | | | Add a new sysfs interface that allows the bitmap of an array to be dirtied. The interface is write-only, and is used as follows: echo "1000" > /sys/block/md2/md/bitmap (dirty the bit for chunk 1000 [offset 0] in the in-memory and on-disk bitmaps of array md2) echo "1000-2000" > /sys/block/md1/md/bitmap (dirty the bits for chunks 1000-2000 in md1's bitmap) This is useful, for example, in cluster environments where you may need to combine two disjoint bitmaps into one (following a server failure, after a secondary server has taken over the array). By combining the bitmaps on the two servers, a full resync can be avoided (This was discussed on the list back on March 18, 2005, "[PATCH 1/2] md bitmap bug fixes" thread). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] md: Change md/bitmap file handling to use bmap to file blocks-fixNeilBrown2006-06-26
| | | | | | | | | | | | | | | Fix problems with new bmap based access to bitmap files. 1/ When not using a file based bitmap, attach a NULL list of buffers to each page so the common free_buffer routine can cope. 2/ Use submit_bh to read as well as write, rather than vfs_read. This makes read and write more symetric. 3/ sync the file before reading, to ensure that the page cache has no dirty pages that might get written out later. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: change md/bitmap file handling to use bmap to file blocksNeilBrown2006-06-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If md is asked to store a bitmap in a file, it tries to hold onto the page cache pages for that file, manipulate them directly, and call a cocktail of operations to write the file out. I don't believe this is a supportable approach. This patch changes the approach to use the same approach as swap files. i.e. bmap is used to enumerate all the block address of parts of the file and we write directly to those blocks of the device. swapfile only uses parts of the file that provide a full pages at contiguous addresses. We don't have that luxury so we have to cope with pages that are non-contiguous in storage. To handle this we attach buffers to each page, and store the addresses in those buffers. With this approach the pagecache may contain data which is inconsistent with what is on disk. To alleviate the problems this can cause, md invalidates the pagecache when releasing the file. If the file is to be examined while the array is active (a non-critical but occasionally useful function), O_DIRECT io must be used. And new version of mdadm will have support for this. This approach simplifies a lot of code: - we no longer need to keep a list of pages which we need to wait for, as the b_endio function can keep track of how many outstanding writes there are. This saves a mempool. - -EAGAIN returns from write_page are no longer possible (not sure if they ever were actually). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: tidy up i_writecount handling in md/bitmapNeilBrown2006-06-26
| | | | | | | | | | | | md/bitmap modifies i_writecount of a bitmap file to make sure that no-one else writes to it. The reverting of the change is sometimes done twice, and there is one error path where it is omitted. This patch tidies that up. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: remove dead code from md/bitmapNeilBrown2006-06-26
| | | | | | | | | | | bitmap_active is never called, and the BITMAP_ACTIVE flag is never users or tested, so discard them both. Also remove some out-of-date 'todo' comments. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: remove unnecessary page reference manipulations from ↵NeilBrown2006-06-26
| | | | | | | | | | | | | | | | | | | md/bitmap code md/bitmap gets a collection of pages representing the bitmap when it initialises the bitmap, and puts all the references when discarding the bitmap. It also occasionally takes extra references without any good reason, and sometimes drops them ... though it doesn't always drop them, which can result in a memory leak. This patch removes the unnecessary 'get_page' calls, and the corresponding 'put_page' calls. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: use set_bit etc for bitmap page attributesNeilBrown2006-06-26
| | | | | | | | | In particular, this means that we use 4 bits per page instead of a whole unsigned long. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: cleaner separation of page attribute handlers in md/bitmapNeilBrown2006-06-26
| | | | | | | | | | | | md/bitmap has some attributes per-page. Handling of these attributes in largely abstracted in set_page_attr and clear_page_attr. However get_page_attr exposes the format used to store them. So prior to changing that format, introduce test_page_attr instead of get_page_attr, and make appropriate usage changes. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md/bitmap: remove bitmap writeback daemonNeilBrown2006-06-26
| | | | | | | | | | | | | md/bitmap currently has a separate thread to wait for writes to the bitmap file to complete (as we cannot get a callback on that action). However this isn't needed as bitmap_unplug is called from process context and waits for the writeback thread to do it's work. The same result can be achieved by doing the waiting directly in bitmap_unplug. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mempool: use common mempool kmalloc allocatorMatthew Dobson2006-03-26
| | | | | | | | | | This patch changes several mempool users, all of which are basically just wrappers around kmalloc(), to use the common mempool_kmalloc/kfree, rather than their own wrapper function, removing a bunch of duplicated code. Signed-off-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds2006-03-25
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (21 commits) BUG_ON() Conversion in drivers/video/ BUG_ON() Conversion in drivers/parisc/ BUG_ON() Conversion in drivers/block/ BUG_ON() Conversion in sound/sparc/cs4231.c BUG_ON() Conversion in drivers/s390/block/dasd.c BUG_ON() Conversion in lib/swiotlb.c BUG_ON() Conversion in kernel/cpu.c BUG_ON() Conversion in ipc/msg.c BUG_ON() Conversion in block/elevator.c BUG_ON() Conversion in fs/coda/ BUG_ON() Conversion in fs/binfmt_elf_fdpic.c BUG_ON() Conversion in input/serio/hil_mlc.c BUG_ON() Conversion in md/dm-hw-handler.c BUG_ON() Conversion in md/bitmap.c The comment describing how MS_ASYNC works in msync.c is confusing rcu: undeclared variable used in documentation fix typos "wich" -> "which" typo patch for fs/ufs/super.c Fix simple typos tabify drivers/char/Makefile ...
| * BUG_ON() Conversion in md/bitmap.cEric Sesterhenn2006-03-24
| | | | | | | | | | | | | | | | this changes if() BUG(); constructs to BUG_ON() which is cleaner and can better optimized away Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* | [PATCH] md/bitmap.c:bitmap_mask_state(): fix inconsequent NULL checkingAdrian Bunk2006-03-25
|/ | | | | | | | | | | | | We dereference bitmap both one line above and one line below this check rendering this check quite useless. Spotted by the Coverity checker. Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Unlinline a bunch of other functionsArjan van de Ven2006-01-14
| | | | | | | | | | | Remove the "inline" keyword from a bunch of big functions in the kernel with the goal of shrinking it by 30kb to 40kb Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jeff Garzik <jgarzik@pobox.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: make sure bitmap updates are visible through filesystemNeilBrown2006-01-06
| | | | | | | | | When we update a page_cache page in the kernel, we need to flush_dache_page or userspace might not see the change. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: define and use safe_put_page for mdNeilBrown2006-01-06
| | | | | | | | | md sometimes call put_page on NULL pointers (treating it like kfree). This is not safe, so define and use a 'safe_put_page' which checks for NULL. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: remove inappropriate limits in md/bitmap configuration.NeilBrown2006-01-06
| | | | | | | | | | | The kernel should not be imposing these policy limits: The time between bitmap updates should certainly be allowed to be more than 15 seconds, and if someone wants a bitmap chunk size in excess of 4MB, the kernel isn't the place to stop them. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: convert various kmap calls to kmap_atomicNeilBrown2006-01-06
| | | | | | Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: convert md to use kzalloc throughoutNeilBrown2006-01-06
| | | | | | | | Replace multiple kmalloc/memset pairs with kzalloc calls. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: clean up 'page' related names in mdNeilBrown2006-01-06
| | | | | | | | | | | | | | | | | Substitute: page_cache_get -> get_page page_cache_release -> put_page PAGE_CACHE_SHIFT -> PAGE_SHIFT PAGE_CACHE_SIZE -> PAGE_SIZE PAGE_CACHE_MASK -> PAGE_MASK __free_page -> put_page because we aren't using the page cache, we are just using pages. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: move bitmap_create to after md array has been initialisedNeilBrown2006-01-06
| | | | | | | | | | | | | | | | | This is important because bitmap_create uses mddev->resync_max_sectors and that doesn't have a valid value until after the array has been initialised (with pers->run()). [It doesn't make a difference for current personalities that support bitmaps, but will make a difference for raid10] This has the added advantage of meaning with can move the thread->timeout manipulation inside the bitmap.c code instead of sprinkling identical code throughout all personalities. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: don't pass a NULL file* into ->prepare_write()Neil Brown2005-11-18
| | | | | | | | Some filesystems go oops. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: support BIO_RW_BARRIER for md/raid1NeilBrown2005-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can only accept BARRIER requests if all slaves handle barriers, and that can, of course, change with time.... So we keep track of whether the whole array seems safe for barriers, and also whether each individual rdev handles barriers. We initially assumes barriers are OK. When writing the superblock we try a barrier, and if that fails, we flag things for no-barriers. This will usually clear the flags fairly quickly. If writing the superblock finds that BIO_RW_BARRIER is -ENOTSUPP, we need to resubmit, so introduce function "md_super_wait" which waits for requests to finish, and retries ENOTSUPP requests without the barrier flag. When writing the real raid1, write requests which were BIO_RW_BARRIER but which aresn't supported need to be retried. So raid1d is enhanced to do this, and when any bio write completes (i.e. no retry needed) we remove it from the r1bio, so that devices needing retry are easy to find. We should hardly ever get -ENOTSUPP errors when writing data to the raid. It should only happen if: 1/ the device used to support BARRIER, but now doesn't. Few devices change like this, though raid1 can! or 2/ the array has no persistent superblock, so there was no opportunity to pre-test for barriers when writing the superblock. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: make md on-disk bitmaps not host-endianNeilBrown2005-11-09
| | | | | | | | | | | Current bitmaps use set_bit et.al and so are host-endian, which means not-portable. Oops. Define a new version number (4) for which bitmaps are little-endian. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>