1. 21 Jul, 2002 8 commits
    • Alexander Viro's avatar
      [PATCH] paride cleanup and fixes · b92b31a3
      Alexander Viro authored
      somewhat related to the above - drivers/block/paride/* switched to
      module_init()/module_exit(), pd.c taught to use LBA if disks support
      it (needed for paride disks >8Gb; change is fairly trivial and I've
      got 40Gb one ;-)
      b92b31a3
    • Alexander Viro's avatar
      [PATCH] blk_ioctl() not exported anymore · 9d16ed71
      Alexander Viro authored
      blk_ioctl() not exported anymore; calls moved from drivers to block_dev.c.
      9d16ed71
    • Alexander Viro's avatar
      [PATCH] partition handling locking cleanups · 81d4c00c
      Alexander Viro authored
      Horrors with open/reread_partition exclusion are starting to get fixed.
      
      It's not the final variant, but at least we are getting the logics into
      one place; switch to final variant will happen once we get per-disk
      analog of gendisks.  New fields - ->bd_part_sem and ->bd_part_count.
      
      The latter counts the amount of opened partitions.  The former protects
      said count _and_ is held while we are rereading partition tables.
      Helpers - dev_part_lock()/dev_part_unlock() (currently taking kdev_t; that
      will change pretty soon).  No more ->open() and ->release() for partitions,
      all that logics went to generic code.  Lock hierachy is currently messy:
      
        ->bd_sem for partitions -> ->bd_part_sem -> ->bd_sem for entire disks
      
      Ugly, but that'll go away and to get the final variant of locking right
      now would take _really_ big patch - with a lot of steps glued together.
      The damn thing is large as it is...
      81d4c00c
    • Alexander Viro's avatar
      [PATCH] block device size cleanups · 5844ac33
      Alexander Viro authored
      for partitioned devices we use ->nr_sect to find the size; blk_size[] is
      still used for things like floppy.c, etc.; that will go away later.
      
      There was only one place (do_open()) that needed it - the rest uses
      ->bd_inode->i_size now.  So blkdev_size_in_bytes() is gone - it's
      expanded in its only caller.  Same place (do_open()) finds the partition
      offset and stores it in new field ->bd_offset.  As the result, call of
      get_gendisk() is gone from the IO path - in blk_partition_remap() we
      just add ->bd_offset.
      
      Additionally, we take driver probing (get_blkfops()) outside of ->bd_sem
      (again, do_open()) - that will allow to kill ad-hackery in check_partitions()
      (opening bdev by hand).
      5844ac33
    • Alexander Viro's avatar
      [PATCH] partition parsing cleanup · a22f8253
      Alexander Viro authored
      struct gendisk and partition parsers divorced; all these parsers (IBM style,
      disklabel, etc.) just fill the structure they get from check_partitions().
      
      Actual setting the things up (filling hd_struct arrays, telling RAID that
      we had found partitions worth a look, etc.) is taken into check_partitions()
      and done only when we are done with parsing.  Parsers don't know (or care)
      what majors/minors they are dealing with; that knowledge also went to
      check_partitions().
      a22f8253
    • Alexander Viro's avatar
      [PATCH] Use wipe_partitions() where appropriate · d6d4f980
      Alexander Viro authored
      a bunch of places doing invalidate_device() either didn't need it at all
      or actually wanted wipe_partitions().  Switched.
      d6d4f980
    • Alexander Viro's avatar
      [PATCH] make hfs use regular semaphores · a4dea1b6
      Alexander Viro authored
      unrelated to the rest, replaces home-grown (racy) semaphores in fs/hfs
      with the real thing.
      a4dea1b6
    • Linus Torvalds's avatar
      Fix incoherent LDT at mmap exit. · f6daaf1a
      Linus Torvalds authored
      We should _not_ update the current LDT if it's not the current
      MM that we are tearing down.
      f6daaf1a
  2. 20 Jul, 2002 3 commits
  3. 19 Jul, 2002 29 commits
    • Greg Kroah-Hartman's avatar
      LSM: for now, always set CONFIG_SECURITY_CAPABILITIES to y · 7a19fd4a
      Greg Kroah-Hartman authored
      This can be overridden by editing the .config file if you really want it.
      7a19fd4a
    • Linus Torvalds's avatar
      Merge bk://lsm.bkbits.net/linus-2.5 · 3bfd74ba
      Linus Torvalds authored
      into home.transmeta.com:/home/torvalds/v2.5/linux
      3bfd74ba
    • Greg Kroah-Hartman's avatar
    • Greg Kroah-Hartman's avatar
      LSM: Add all of the new security/* files for basic task control · 2b15fe63
      Greg Kroah-Hartman authored
      This includes the security_* functions, and the default and capability
      modules.
      2b15fe63
    • Greg Kroah-Hartman's avatar
      LSM: change BUS_ISA to CTL_BUS_ISA to prevent namespace collision with the input subsystem. · c59ccd5f
      Greg Kroah-Hartman authored
      This is needed due to the next header file changes.
      c59ccd5f
    • Hirofumi Ogawa's avatar
      [PATCH] Add 4G-1 file support to FAT32 · d4db5063
      Hirofumi Ogawa authored
      This patch changes cont_prepare_write(), in order to support a 4G-1
      file for FAT32.
      
       int cont_prepare_write(struct page *page, unsigned offset,
      -		unsigned to, get_block_t *get_block, unsigned long *bytes)
      +		unsigned to, get_block_t *get_block, loff_t *bytes)
      
      And it fixes broken adfs/affs/fat/hfs/hpfs/qnx4 by this
      cont_prepare_write() change.
      d4db5063
    • Linus Torvalds's avatar
      Merge http://linuxusb.bkbits.net/linus-2.5 · 047cef32
      Linus Torvalds authored
      into home.transmeta.com:/home/torvalds/v2.5/linux
      047cef32
    • Andrew Morton's avatar
      [PATCH] readahead optimisations · b6938a7b
      Andrew Morton authored
      Been looking at a workload which involves several processes which seek
      around and read from a large file.  There are a few problems:
      generic_file_lseek is bouncing i_sem around like mad, and readahead is
      doing lots of pointless pagecache probing.
      
      This patch addresses readahead.
      
      Presumably the change will be larger on machines which have higher
      bandwidth memory than my test box, of which there are many.
      
      This patch teaches readahead to detect the situation where no IO is
      actually being performed as a result of its actions.  Now, we don't
      want to sacrifice IO efficiency to save a bit of CPU, so the code is
      very cautious.  But eventually, after some tens of consecutive
      readahead attempts were found to perform no I/O at all, readahead will
      turn itself off.
      
      readahead will be turned on again when either generic_file_read() or
      filemap_nopage() get a pagecache miss.  The function
      handle_ra_thrashing() has been renamed to handle_ra_miss() to reflect
      its widened role.
      
      A performance bug in page_cache_readround() was fixed - if
      ra->next_size is zero, that function needs to leave it well alone,
      because next_size==0 is a magic value meaning that the file has just
      been opened and that readahead needs to get aggressive.  This change
      makes a `make dep' run at the same speed as in the 2.4 kernel.  It used
      to take 4x as long...
      
      `make dep' is an interesting test because it uses mmap to read the files.
      b6938a7b
    • Andrew Morton's avatar
      [PATCH] writeback scalability improvements · e64fa3db
      Andrew Morton authored
      The kernel has a number of problems wrt heavy write traffic to multiple
      spindles.  What keeps on happening is that all processes which are
      responsible for writeback get blocked on one of the queues and all the
      others fall idle.
      
      This happens in the balance_dirty_pages() path (balance_dirty() in 2.4)
      and in the page reclaim code, when a dirty page is found on the LRU.
      
      The latter is particularly bad because it causes "innocent" processes
      to be suspended for long periods due to the activity of heavy writers.
      
      The general idea is: the primary resource for writeback should be the
      process which is dirtying memory.  The secondary resource is the
      pdflush pool (although this is mainly for providing async writeback in
      the presence of light-moderate loads).  Add the final
      oh-gee-we-screwed-up resource for writeback is a caller to
      shrink_cache().
      
      This patch addresses the balance_dirty_pages() path.  This code was
      initially modelled on the 2.4 writeback scheme: throttled processes
      writeback all data regardless of its queue.  Instead, the patch changes
      it so that the balance_dirty_pages() caller only writes back pages
      which are dirty against the queue which that caller just dirtied.
      
      So the effect is a better allocation of writeback resources across the
      queues and increased parallelism.
      
      The per-queue writeback is implemented by using
      mapping->backing_dev_info as a search key during the walk across the
      superblocks and inodes.
      
      The patch also fixes an initialisation problem in
      block_dev.c:do_open(): it was setting up the blockdev's
      mapping->backing_dev_info too early, before the queue has been
      identified.
      
      Generally, this patch doesn't help much, because of the stalls in the
      page allocator.  I have a patch which mostly fixes that up, and taken
      together the kernel is achieving almost platter speed against six
      spindles, but only when the system has a small amount of memory.  More
      work is needed there.
      e64fa3db
    • Andrew Morton's avatar
      [PATCH] remove add_to_page_cache_unique() · cad46d66
      Andrew Morton authored
      A tasty patch from Hugh Dickens.  radix_tree_insert() fails if something
      was already present at the target index, so that error can be
      propagated back through add_to_page_cache().  Hence
      add_to_page_cache_unique() is obsolete.
      
      Hugh's patch removes add_to_page_cache_unique() and cleans up a bunch of
      stuff.
      cad46d66
    • Andrew Morton's avatar
      [PATCH] direct_io mopup · e3339bee
      Andrew Morton authored
      Some cleanup from the surprise direct-to-bio for O_DIRECT merge.
      
      - Remove bits and pieces from the kiobuf implementation
      
      - Replace the waitqueue in struct dio with just a task_struct pointer
        and use wake_up_process.  (Ben).
      
      - Only take mmap_sem around the individual calls to get_user_pages().
         (It pins the vmas, yes?)
      
      - Remove some debug code.
      
      - Fix JFS.
      e3339bee
    • Andrew Morton's avatar
      [PATCH] alloc_pages cleanup · 4504a57e
      Andrew Morton authored
      Cleanup patch from Martin Bligh: convert some loops which want to be
      `for' loops into that, and add some commentary.
      4504a57e
    • Andrew Morton's avatar
      [PATCH] inline generic_writepages() · 15a37ba2
      Andrew Morton authored
      generic_writepages() is just a wrapper around mpage_writepages(), so
      inline it.
      15a37ba2
    • Andrew Morton's avatar
      [PATCH] restore CHECK_EMERGENCY_SYNC. Again. · 3d4ed856
      Andrew Morton authored
      Put the CHECK_EMERGENCY_SYNC back into the kupdate function.  I seem to
      keep removing it.
      3d4ed856
    • Andrew Morton's avatar
      [PATCH] O_DIRECT open check · 7d0be429
      Andrew Morton authored
      Updated forward-port of Aodrea's O_DIRECT open() checks.  If the user
      asked for O_DIRECT and the inode has no mapping or no a_ops then fail
      the open up-front.
      7d0be429
    • Andrew Morton's avatar
      [PATCH] VM instrumentation · e177ea28
      Andrew Morton authored
      A patch from Rik which adds some operational statitics to the VM.
      
      In /proc/meminfo:
      
      PageTables:	Amount of memory used for process pagetables
      PteChainTot:	Amount of memory allocated for pte_chain objects
      PteChainUsed:	Amount of memory currently in use for pte chains.
      
      In /proc/stat:
      
      pageallocs:	Number of pages allocated in the page allocator
      pagefrees:	Number of pages returned to the page allocator
      
      		(These can be used to measure the allocation rate)
      
      pageactiv:	Number of pages activated (moved to the active list)
      pagedeact:	Number of pages deactivated (moved to the inactive list)
      pagefault:	Total pagefaults
      majorfault:	Major pagefaults
      pagescan:	Number of pages which shrink_cache looked at
      pagesteal:	Number of pages which shrink_cache freed
      pageoutrun:	Number of calls to try_to_free_pages()
      allocstall:	Number of calls to balance_classzone()
      
      
      Rik will be writing a userspace app which interprets these things.
      
      The /proc/meminfo stats are efficient, but the /proc/stat accumulators
      will cause undesirable cacheline bouncing.  We need to break the disk
      statistics out of struct kernel_stat and make everything else in there
      per-cpu.  If that doesn't happen in time for 2.6 then we disable
      KERNEL_STAT_INC().
      e177ea28
    • Andrew Morton's avatar
      [PATCH] avoid allocating pte_chains for unshared pages · 6a2ea338
      Andrew Morton authored
      Patch from David McCracken.  It is an optimisation to the rmap
      pte_chains.
      
      In the common case where a page is mapped by only a single pte, we
      don't need to allocate a pte_chain structure.  Just make the page's
      pte_chain pointer point straight at that pte and flag this with
      PG_direct.
      6a2ea338
    • Andrew Morton's avatar
      [PATCH] leave truncate's orphaned pages on the LRU · fa08cc83
      Andrew Morton authored
      Fix to the page reclaim code from Rik.
      
      Anonymous pages which have buffers arise when
      truncate_complete_page()'s call to ->releasepage() failed.  Those pages
      may still be mapped into process address spaces.
      
      We should not remove them from the LRU, because that makes them
      unswappable and they hang around until process exit.
      fa08cc83
    • Andrew Morton's avatar
      [PATCH] minimal rmap · c48c43e6
      Andrew Morton authored
      This is the "minimal rmap" patch, writen by Rik, ported to 2.5 by Craig
      Kulsea.
      
      Basically,
      
      before: When the page reclaim code decides that is has scanned too many
      unreclaimable pages on the LRU it does a scan of process virtual
      address spaces for pages to add to swapcache.  ptes pointing at the
      page are unmapped as the scan proceeds.  When all ptes referring to a
      page have been unmapped and it has been written to swap the page is
      reclaimable.
      
      after: When an anonymous page is encountered on the tail of the LRU we
      use the rmap to see if it hasn't been referenced lately.  If so then
      add it to swapcache.  When the page is again encountered on the LRU, if
      it is still unreferenced then try to unmap all ptes which refer to it
      in one hit, and if it is clean (ie: on swap) then free it.
      
      The rest of the VM - list management, the classzone concept, etc
      remains unchanged.
      
      There are a number of things which the per-page pte chain could be
      used for.  Bill Irwin has identified the following.
      
      
      (1)  page replacement no longer goes around randomly unmapping things
      
      (2)  referenced bits are more accurate because there aren't several ms
              or even seconds between find the multiple pte's mapping a page
      
      (3)  reduces page replacement from O(total virtually mapped) to O(physical)
      
      (4)  enables defragmentation of physical memory
      
      (5)  enables cooperative offlining of memory for friendly guest instance
              behavior in UML and/or LPAR settings
      
      (6)  demonstrable benefit in performance of swapping which is common in
              end-user interactive workstation workloads (I don't like the word
              "desktop"). c.f. Craig Kulesa's post wrt. swapping performance
      
      (7)  evidence from 2.4-based rmap trees indicates approximate parity
              with mainline in kernel compiles with appropriate locking bits
      
      (8)  partitioning of physical memory can reduce the complexity of page
              replacement searches by scanning only the "interesting" zones
              implemented and merged in 2.4-based rmap
      
      (9)  partitioning of physical memory can increase the parallelism of page
              replacement searches by independently processing different zones
              implemented, but not merged in 2.4-based rmap
      
      (10) the reverse mappings may be used for efficiently keeping pte cache
              attributes coherent
      
      (11) they may be used for virtual cache invalidation (with changes)
      
      (12) the reverse mappings enable proper RSS limit enforcement
              implemented and merged in 2.4-based rmap
      
      
      
      The code adds a pointer to struct page, consumes additional storage for
      the pte chains and adds computational expense to the page reclaim code
      (I measured it at 3% additional load during streaming I/O).  The
      benefits which we get back for all this are, I must say, theoretical
      and unproven.  If it has real advantages (or, indeed, disadvantages)
      then why has nobody demonstrated them?
      
      
      
      There are a number of things remaining to be done:
      
      1: Demonstrate the above advantages.
      
      2: Make it work with pte-highmem  (Bill Irwin is signed up for this)
      
      3: Don't add pte_chains to non-shared pages optimisation (Dave McCracken's
         patch does this)
      
      4: Move the pte_chains into highmem too (Bill, I guess)
      
      5: per-cpu pte_chain freelists (Rik?)
      
      6: maybe GC the pte_chain backing pages. (Seems unavoidable.  Rik?)
      
      7: multithread the page reclaim code.  (I have patches).
      
      8: clustered add-to-swap.  Not sure if I buy this.  anon pages are
         often well-ordered-by-virtual-address on the LRU, so it "just
         works" for benchmarky loads.  But there may be some other loads...
      
      9: Fix bad IO latency in page reclaim (I have lame patches)
      
      10: Develop tuning tools, use them.
      
      11: The nightly updatedb run is still evicting everything.
      c48c43e6
    • Linus Torvalds's avatar
      Merge bk://lsm.bkbits.net/linus-2.5 · b15d45bf
      Linus Torvalds authored
      into home.transmeta.com:/home/torvalds/v2.5/linux
      b15d45bf
    • Linus Torvalds's avatar
      Merge http://linuxusb.bkbits.net/agpgart-2.5 · faaab2cf
      Linus Torvalds authored
      into home.transmeta.com:/home/torvalds/v2.5/linux
      faaab2cf
    • Stuart MacDonald's avatar
      [PATCH] USB: usbserial.c fixup · 23c7f059
      Stuart MacDonald authored
      create_serial, get_free_serial and usb_serial_probe all do pretty much
      the same thing. I'd like to reorg this into create_serial does all the
      alloc and most of the setup, and get_free_serial just fills in the
      MAGIC.
      
      There's currently a memory leak: if create_serial is called at probe
      time or calc_ports time, and then get_free_serial returns NULL because
      the table has no entries left, that usb_serial struct is leaked.
      
      get_free_serial doesn't check properly for free slots. The middle loop
      doesn't terminate when the end of the table is reached, although the
      assignment loop later does. The effect is that stuff past the end of
      the table is allowed to decide if there's free space or not, and
      occasionally it'll say "yes" and then the assignment loop will only
      allocate slots up to the end of the table, preventing memory
      scribbling.
      
      I haven't fixed any of this just yet because I'm not sure what the
      intended behaviour is. Should get_free_serial allocate as many slots
      as possible, or just be all or nothing? Similarly, I don't see a
      problem with calling create_serial early in usb_serial_probe, and
      removing the alloc code from get_free_serial; this would fix the leak.
      
      Ah heck, here's a patch. This is what I think things should look like.
      get_free_serial is all or none, the leak is fixed and create_serial
      does all the allocation.
      23c7f059
    • Rusty Russell's avatar
      [PATCH] drivers/usb/* designated initializer rework · cfe2b798
      Rusty Russell authored
      Name: Designated initializers for drivers/usb
      Author: Rusty Russell
      Status: Trivial
      
      D: The old form of designated initializers are obsolete: we need to
      D: replace them with the ISO C forms before 2.6.  Gcc has always supported
      D: both forms anyway.
      cfe2b798
    • Martin Dalecki's avatar
      [PATCH] IDE 100 · 84f4a1c4
      Martin Dalecki authored
        Trivia time:
      
        - C99 conforming initializations by Rusty.
      
        - ide__sti() -> local_irq_enable() and its friends.
      84f4a1c4
    • Martin Dalecki's avatar
      [PATCH] 2.5.26 IDE 99 · e9356da8
      Martin Dalecki authored
      Most noticable in the patch:
      
      1. we handle IRQ sharing now better then ever
      
      2. survives quite a lot of testing by few people. Forexample
      cat /dev/hdb > /dev/null, where /dev/hdb contains a CD-ROM
      with a big cratch on the surface making sure it's broken :-).
      it's BTW. amanzing how wide the cratch had to be until errors
      ocurred.
      
      3. Doesn't play with rq_rdev and friends
      
      Fri Jul 12 05:04:32 CEST 2002 ide-clean-99
      
      - Push nIEN disabling down at the place where we are finished with a particular
         request.
      
      - First round of command line parser cleanups by Gerald Champagne.
      
      - Unfold the drive eviction functions in do_request(). This allowed us to
         realize that we don't have to re-get the major/minor numbers of the device we
         are action on from the raw device field of the currently running request. One
         significant place less in kernel where major/minor data gets manipulated.
      
      - Move the big IDE_BUSY loop out of do_request to do_ide_request().  This makes
         us realize that we don't have to clear the IDE_BUSY bit just before
         reentering do_request to look for more requests still pending on the queue
         and set it immediately again.
      
         This is fixing a tinny race on the code path from IRQ or timer function,
         where we had a tinny window between the clearing of the IDE_BUSY bit and
         reentering the request queue for completely unrelated requests to come in to
         our way.
      
      - Don't return any value in do_reset1(). It's always ATA_OP_CONTINUES. Split it
         up in to two functions one for disks (well in fact channels) and one for
         ATAPI devices. It turns out that they can be moved to the places where they
         are used to clarify the code flow. The only function remaining is
         do_reset_channel() now.
      
      - Duplicate code from ide_do_drive_code explicitely in ide_raw_taskfile().
         Simplify ide_raw_taskfile() thereafter. Realize that ide_do_drive_cmd()
         is now only used by ATAPI devices. Move it therefore to atapi.c.
      
      - Do busy polling for ATAPI reset operations. This is much safer then the
         previous timer games played there. It simply doesn't make sense to give the
         bus up during such a subtile operation. We don't have to disable IRQs here as
         well, since we are already under the protection of the do_request mechanisms.
         (Well hopefully...)
      
      - Remove no longer used reset_poll() function. poll_timeout and friends are now
         used only in pdc4030 code. Those function where not called from IRQ context
         but they where set as handlers and not as expiry functions.
      
      - Return ATA_OP_CONTINUES instead of ATA_OP_FINISHED in ata_error(), to signal
         that we are willing to retry the operation until the maximal number of retry
         attempts is exceeded. Returning ATA_OP_FINISHED without prior end_request()
         hangs the system.
      
      - Apply trivia from DJ patch set.
      
      - Apply small configuration fix to ide-pci.c from Muli Ben-Yehuda.
      
      - Feed add_blkdev_randomness with information we already have in struct
         ata_channel *ch->major, instead of using the major(macro) on the request in
         question.
      
      - Make ide_raw_taskfile use the same request submission mechanism as
         tcq_invalidate_queue(). Something similar would be ideal for ioctl() code as
         well.
      
      - Implement actual device reset. Realize that the recalibration procedure is
         doomed by the standard. Don't try to recover by recalibrating devices
         therefore -just our retry mechanism should work in those cases. And suddenly
         the error handling code is IRQ safe.
      
      - Reinvent the ATA reset operation, since it is apparently needed. We still
         have to do the whole transfer timing reconfiguration there.
      
      - Move drive_is_ready(), which is in reality an attempt to check for IRQ
         requesters without clearing the IRQ line, over to the place where it belongs:
         device.c, which is the direct device access abstraction place.  Rename it to
         ata_status_irq() to prevent global name space pollution.
      
      - Updates to the pdc202xxx host chip controller setup code by Bart³omiej
         ¯o³nierkiewicz:
      
         Forward port 2.4 patch by Hank Yang from Promise:
      
      	- Add PDC20271 support
      	- Disable LBA48 support on PDC20262
      	- Fix ATAPI UDMA port value
      	- Add new quirk drive
      	- Adjust timings for all drives when using ATA133
      	- Update pdc202xx_reset() waiting time
      
      - Mark TCQ as dangerous and add some bits about it to the help.
      
      - Add some missing exports.
      
      - Some small ide-scsi.c host allocation fixes by sullivan.
      e9356da8
    • Neil Brown's avatar
      [PATCH] MD - Get rid of dev in rdev and use bdev exclusively. · 3ec59360
      Neil Brown authored
      Get rid of dev in rdev and use bdev exclusively.
      
      There is an awkwardness here in that userspace sometimes
      passed down a dev_t (e.g. hot_add_disk) and sometime
      a major and a minor (e.g. add_new_disk).  Should we convert
      both to kdev_t as the uniform standard....
      That is what was being done but it seemed very clumsy and
      things were gets converted back and forth a lot.
      
      As bdget used a dev_t, I felt safe in staying with dev_t once I
      had one rather than converting to kdev_t and back.
      3ec59360
    • Neil Brown's avatar
      [PATCH] MD - Change partition_name calls to bdev_partition_name were possible. · c4909782
      Neil Brown authored
      Change partition_name calls to bdev_partition_name were possible.
      
      All part of decreasing reliance on device numbers... atleast in
      appearance.
      c4909782
    • Neil Brown's avatar
      [PATCH] MD - Remove the sb from the mddev · 43fb3e86
      Neil Brown authored
      Remove the sb from the mddev
      
      Now that al the important information is in mddev, we don't need
      to have an sb off the mddev.  We only keep the per-device ones.
      
      Previously we determined if "set_array_info" had been run byb checking
      mddev->sb.  Now we check mddev->raid_disks on the assumption that
      any valid array MUST have a non-zero number of devices.
      43fb3e86
    • Neil Brown's avatar
      [PATCH] MD - Remove dependance on superblock · bab5d712
      Neil Brown authored
      Remove dependance on superblock
      
      All the remaining field of interest in the superblock
      get duplicated in the mddev struture and this is treated as
      authoritative.  The superblock gets completely generated at
      write time, and all useful information extracted at read time.
      
      This means that we can slot in different superblock formats
      without affecting the bulk of the code.
      bab5d712