1. 14 Jun, 2018 1 commit
  2. 16 Apr, 2018 1 commit
  3. 05 Jun, 2017 1 commit
  4. 27 Jan, 2016 1 commit
  5. 14 Apr, 2015 3 commits
    • Vladimir Davydov's avatar
      cleancache: remove limit on the number of cleancache enabled filesystems · 3cb29d11
      Vladimir Davydov authored
      The limit equals 32 and is imposed by the number of entries in the
      fs_poolid_map and shared_fs_poolid_map.  Nowadays it is insufficient,
      because with containers on board a Linux host can have hundreds of
      active fs mounts.
      
      These maps were introduced by commit 49a9ab81
      
       ("mm: cleancache:
      lazy initialization to allow tmem backends to build/run as modules") in
      order to allow compiling cleancache drivers as modules.  Real pool ids
      are stored in these maps while super_block->cleancache_poolid points to
      an entry in the map, so that on cleancache registration we can walk over
      all (if there are <= 32 of them, of course) cleancache-enabled super
      blocks and assign real pool ids.
      
      Actually, there is absolutely no need in these maps, because we can
      iterate over all super blocks immediately using iterate_supers.  This is
      not racy, because cleancache_init_ops is called from mount_fs with
      super_block->s_umount held for writing, while iterate_supers takes this
      semaphore for reading, so if we call iterate_supers after setting
      cleancache_ops, all super blocks that had been created before
      cleancache_register_ops was called will be assigned pool ids by the
      action function of iterate_supers while all newer super blocks will
      receive it in cleancache_init_fs.
      
      This patch therefore removes the maps and hence the artificial limit on
      the number of cleancache enabled filesystems.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Stefan Hengelein <ilendir@googlemail.com>
      Cc: Florian Schmaus <fschmaus@gmail.com>
      Cc: Andor Daam <andor.daam@googlemail.com>
      Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
      Cc: Bob Liu <lliubbo@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3cb29d11
    • Vladimir Davydov's avatar
      cleancache: forbid overriding cleancache_ops · 53d85c98
      Vladimir Davydov authored
      
      
      Currently, cleancache_register_ops returns the previous value of
      cleancache_ops to allow chaining.  However, chaining, as it is
      implemented now, is extremely dangerous due to possible pool id
      collisions.  Suppose, a new cleancache driver is registered after the
      previous one assigned an id to a super block.  If the new driver assigns
      the same id to another super block, which is perfectly possible, we will
      have two different filesystems using the same id.  No matter if the new
      driver implements chaining or not, we are likely to get data corruption
      with such a configuration eventually.
      
      This patch therefore disables the ability to override cleancache_ops
      altogether as potentially dangerous.  If there is already cleancache
      driver registered, all further calls to cleancache_register_ops will
      return EBUSY.  Since no user of cleancache implements chaining, we only
      need to make minor changes to the code outside the cleancache core.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Stefan Hengelein <ilendir@googlemail.com>
      Cc: Florian Schmaus <fschmaus@gmail.com>
      Cc: Andor Daam <andor.daam@googlemail.com>
      Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
      Cc: Bob Liu <lliubbo@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      53d85c98
    • Vladimir Davydov's avatar
      cleancache: zap uuid arg of cleancache_init_shared_fs · 9de16262
      Vladimir Davydov authored
      
      
      Use super_block->s_uuid instead.  Every shared filesystem using cleancache
      must now initialize super_block->s_uuid before calling
      cleancache_init_shared_fs.  The only one on the tree, ocfs2, already meets
      this requirement.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Stefan Hengelein <ilendir@googlemail.com>
      Cc: Florian Schmaus <fschmaus@gmail.com>
      Cc: Andor Daam <andor.daam@googlemail.com>
      Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
      Cc: Bob Liu <lliubbo@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9de16262
  6. 20 Jan, 2015 1 commit
  7. 24 Jan, 2014 1 commit
  8. 01 May, 2013 3 commits
  9. 26 Feb, 2013 1 commit
  10. 30 May, 2012 1 commit
  11. 23 Jan, 2012 4 commits
  12. 26 May, 2011 1 commit
    • Dan Magenheimer's avatar
      mm: cleancache core ops functions and config · 077b1f83
      Dan Magenheimer authored
      
      
      This third patch of eight in this cleancache series provides
      the core code for cleancache that interfaces between the hooks in
      VFS and individual filesystems and a cleancache backend.  It also
      includes build and config patches.
      
      Two new files are added: mm/cleancache.c and include/linux/cleancache.h.
      
      Note that CONFIG_CLEANCACHE can default to on; in systems that do
      not provide a cleancache backend, all hooks devolve to a simple
      check of a global enable flag, so performance impact should
      be negligible but can be reduced to zero impact if config'ed off.
      However for this first commit, it defaults to off.
      
      Details and a FAQ can be found in Documentation/vm/cleancache.txt
      
      Credits: Cleancache_ops design derived from Jeremy Fitzhardinge
      design for tmem
      
      [v8: dan.magenheimer@oracle.com: fix exportfs call affecting btrfs]
      [v8: akpm@linux-foundation.org: use static inline function, not macro]
      [v7: dan.magenheimer@oracle.com: cleanup sysfs and remove cleancache prefix]
      [v6: JBeulich@novell.com: robustly handle buggy fs encode_fh actor definition]
      [v5: jeremy@goop.org: clean up global usage and static var names]
      [v5: jeremy@goop.org: simplify init hook and any future fs init changes]
      [v5: hch@infradead.org: cleaner non-global interface for ops registration]
      [v4: adilger@sun.com: interface must support exportfs FS's]
      [v4: hch@infradead.org: interface must support 64-bit FS on 32-bit kernel]
      [v3: akpm@linux-foundation.org: use one ops struct to avoid pointer hops]
      [v3: akpm@linux-foundation.org: document and ensure PageLocked reqts are met]
      [v3: ngupta@vflare.org: fix success/fail codes, change funcs to void]
      [v2: viro@ZenIV.linux.org.uk: use sane types]
      Signed-off-by: default avatarDan Magenheimer <dan.magenheimer@oracle.com>
      Reviewed-by: default avatarJeremy Fitzhardinge <jeremy@goop.org>
      Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Acked-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
      Acked-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Acked-by: default avatarNitin Gupta <ngupta@vflare.org>
      Acked-by: default avatarMinchan Kim <minchan.kim@gmail.com>
      Acked-by: default avatarAndreas Dilger <adilger@sun.com>
      Acked-by: default avatarJan Beulich <JBeulich@novell.com>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: Nick Piggin <npiggin@kernel.dk>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Rik Van Riel <riel@redhat.com>
      Cc: Chris Mason <chris.mason@oracle.com>
      Cc: Ted Ts'o <tytso@mit.edu>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <joel.becker@oracle.com>
      077b1f83