- 26 Jun, 2006 40 commits
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NeilBrown authored
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>
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NeilBrown authored
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:
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NeilBrown authored
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 Also remove some out-of-date 'todo' comments.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:
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NeilBrown authored
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:
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NeilBrown authored
In particular, this means that we use 4 bits per page instead of a whole unsigned long. Signed-off-by:
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NeilBrown authored
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:
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NeilBrown authored
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:
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NeilBrown authored
When "mdadm --grow /dev/mdX --bitmap=none" is used to remove a filebacked bitmap, the bitmap was disconnected from the array, but the file wasn't closed (until the array was stopped). The file also wasn't closed if adding the bitmap file failed. Signed-off-by:
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NeilBrown authored
... as raid5 sync_request is WAY too big. Signed-off-by:
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Adrian Bunk authored
This patch makes the needlessly global md_print_devices() static. Signed-off-by:
Adrian Bunk <bunk@stusta.de> Signed-off-by:
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NeilBrown authored
The "industry standard" DDF format allows for a stripe/offset layout where data is duplicated on different stripes. e.g. A B C D D A B C E F G H H E F G (columns are drives, rows are stripes, LETTERS are chunks of data). This is similar to raid10's 'far' mode, but not quite the same. So enhance 'far' mode with a 'far/offset' option which follows the layout of DDFs stripe/offset. Signed-off-by:
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NeilBrown authored
Signed-off-by:
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NeilBrown authored
For a while we have had checkpointing of resync. The version-1 superblock allows recovery to be checkpointed as well, and this patch implements that. Due to early carelessness we need to add a feature flag to signal that the recovery_offset field is in use, otherwise older kernels would assume that a partially recovered array is in fact fully recovered. Signed-off-by:
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NeilBrown authored
At shutdown, we switch all arrays to read-only, which creates a message for every instantiated array, even those which aren't actually active. So remove the message for non-active arrays. Signed-off-by:
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NeilBrown authored
There is a lot of commonality between raid5.c and raid6main.c. This patches merges both into one module called raid456. This saves a lot of code, and paves the way for online raid5->raid6 migrations. There is still duplication, e.g. between handle_stripe5 and handle_stripe6. This will probably be cleaned up later. Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
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NeilBrown authored
When a md array has been idle (no writes) for 20msecs it is marked as 'clean'. This delay turns out to be too short for some real workloads. So increase it to 200msec (the time to update the metadata should be a tiny fraction of that) and make it sysfs-configurable. Signed-off-by:
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NeilBrown authored
This warning was slightly useful back in 2.2 days, but is more an annoyance now. It makes it awkward to add new ioctls (that we we are likely to do that in the current climate, but it is possible). Signed-off-by:
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NeilBrown authored
The largest chunk size the code can support without substantial surgery is 2^30 bytes, so make that the limit instead of an arbitrary 4Meg. Some day, the 'chunksize' should change to a sector-shift instead of a byte-count. Then no limit would be needed. Signed-off-by:
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NeilBrown authored
A recent change made this goto unnecessary, so reformat the code to make it clearer what is happening. Signed-off-by:
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Alasdair G Kergon authored
Tidy device-mapper error messages to include context information automatically. Signed-off-by:
Alasdair G Kergon <agk@redhat.com> Signed-off-by:
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Alasdair G Kergon authored
If you misuse the device-mapper interface (or there's a bug in your userspace tools) it's possible to end up with 'unlinked' mapped devices that cannot be removed until you reboot (along with uninterruptible processes). This patch prevents you from removing a device that is still open. It introduces dm_lock_for_deletion() which is called when a device is about to be removed to ensure that nothing has it open and nothing further can open it. It uses a private open_count for this which also lets us remove one of the problematic bdget_disk() calls elsewhere. Signed-off-by:
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David Teigland authored
Add a library function dm_create_error_table() to create a table that rejects any I/O sent to a device with EIO. Signed-off-by:
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Alasdair G Kergon authored
Move definitions of core device-mapper functions for manipulating mapped devices and their tables to <linux/device-mapper.h> advertising their availability for use elsewhere in the kernel. Protect the contents of device-mapper.h with ifdef __KERNEL__. And throw in a few formatting clean-ups and extra comments. Signed-off-by:
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Alasdair G Kergon authored
Merge dm_create() and dm_create_with_minor() by introducing the special value DM_ANY_MINOR to request the allocation of the next available minor number. Signed-off-by:
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David Teigland authored
Return sense if dm_split_args is called with a NULL input parameter. Signed-off-by:
David Teigland <teigland@redhat.com> Signed-off-by:
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Jonathan Brassow authored
kcopyd should accumulate errors - otherwise I/O failures may be ignored unintentionally. And invert 'success' (used in a future patch), using a more intuitive !(read_err || write_err). Signed-off-by:
Jonathan Brassow <jbrassow@redhat.com> Signed-off-by:
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Alasdair G Kergon authored
When a mirror is reduced in size, clear the part of the bitmap that is no longer used. Signed-off-by:
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Alasdair G Kergon authored
Fix the 'sizeof' in the region log bitmap size calculation: it's uint32_t, not unsigned long - this breaks on some archs. Signed-off-by:
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Alasdair G Kergon authored
Refactor the code that creates the core and disk log contexts to avoid the repeated allocation of clean_bits introduced by the last patch. Signed-off-by:
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Kevin Corry authored
On-disk logs for dm-mirror devices are currently hard-coded to use 512 byte hard-sector-sizes. This patch fixes dm-log so it will work with devices with non-512-byte hard-sector-sizes. To maintain full compatibility, instead of moving the clean-bits bitset to a bitset, and enlarges the disk-header buffer to encompass both the header and the bitset. The I/O routines for the bitset are removed, and the I/O routines for the disk-header now also read/write the bitset. Signed-off-by:
Kevin Corry <kevcorry@us.ibm.com> Signed-off-by:
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Milan Broz authored
The table is indexed from 0, so an index equal to t->num_targets should be rejected. (There is no code in the current tree that would exercise this bug.) Signed-off-by:
Milan Broz <mbroz@redhat.com> Signed-off-by:
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Neil Brown authored
The device-mapper core does not perform any remapping of bios before passing them to the targets. If a particular mapping begins part-way into a device, targets obtain the sector relative to the start of the mapping by subtracting ti->begin. The dm-raid1 target didn't do this everywhere: this patch fixes it, taking care to subtract ti->begin exactly once for each bio. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
In alloc_dev(), we register the device with the block layer and then continue to initialize the device. But register_disk() makes the device available to be opened before we have completed initialising it. This patch moves the final bits of the initialization above the disk registration. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
Jeff Mahoney <jeffm@suse.com> Signed-off-by:
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Jeff Mahoney authored
The reference counting on dm-mod is zero if no mapped devices are open. This is incorrect, and can lead to an oops if the module is unloaded while mapped devices exist. This patch claims a reference to the module whenever a device is created, and drops it again when the device is freed. Devices must be removed before dm-mod is unloaded. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
To avoid races, _minor_lock must be held while changing mapped device reference counts. There are a few paths where a mapped_device pointer is returned before a reference is taken. This patch fixes them. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
There is a chicken and egg problem between the block layer and dm in which the gendisk associated with a mapping keeps a reference-less pointer to the mapped_device. This patch uses a new flag DMF_FREEING to indicate when the mapped_device is no longer valid. This is checked to prevent any attempt to open the device from succeeding while the device is being destroyed. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
While removing a device, another another thread might attempt to resurrect it. This patch replaces the _minor_lock mutex with a spinlock and uses atomic_dec_and_lock() to serialize reference counting in dm_put(). [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
idr_pre_get() can sleep while allocating memory. The next patch will change _minor_lock into a spinlock, so this patch moves idr_pre_get() outside the lock in preparation. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
One part of the system can attempt to use a mapped device before another has finished initialising it or while it is being freed. This patch introduces a place holder value, MINOR_ALLOCED, to mark the minor as allocated but in a state where it can't be used, such as mid-allocation or mid-free. At the end of the initialization, it replaces the place holder with the pointer to the mapped_device, making it available to the rest of the dm subsystem. [akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled] Signed-off-by:
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Jeff Mahoney authored
This patch adds idr_replace() to replace an existing pointer in a single operation. Device-mapper will use this to update the pointer it stored against a given id. Signed-off-by:
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