1. 04 Apr, 2016 1 commit
    • Kirill A. Shutemov's avatar
      mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros · 09cbfeaf
      Kirill A. Shutemov authored
      PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
      ago with promise that one day it will be possible to implement page
      cache with bigger chunks than PAGE_SIZE.
      
      This promise never materialized.  And unlikely will.
      
      We have many places where PAGE_CACHE_SIZE assumed to be equal to
      PAGE_SIZE.  And it's constant source of confusion on whether
      PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
      especially on the border between fs and mm.
      
      Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
      breakage to be doable.
      
      Let's stop pretending that pages in page cache are special.  They are
      not.
      
      The changes are pretty straight-forward:
      
       - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
      
       - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
      
       - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
      
       - page_cache_get() -> get_page();
      
       - page_cache_release() -> put_page();
      
      This patch contains automated changes generated with coccinelle using
      script below.  For some reason, coccinelle doesn't patch header files.
      I've called spatch for them manually.
      
      The only adjustment after coccinelle is revert of changes to
      PAGE_CAHCE_ALIGN definition: we are going to drop it later.
      
      There are few places in the code where coccinelle didn't reach.  I'll
      fix them manually in a separate patch.  Comments and documentation also
      will be addressed with the separate patch.
      
      virtual patch
      
      @@
      expression E;
      @@
      - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
      + E
      
      @@
      expression E;
      @@
      - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
      + E
      
      @@
      @@
      - PAGE_CACHE_SHIFT
      + PAGE_SHIFT
      
      @@
      @@
      - PAGE_CACHE_SIZE
      + PAGE_SIZE
      
      @@
      @@
      - PAGE_CACHE_MASK
      + PAGE_MASK
      
      @@
      expression E;
      @@
      - PAGE_CACHE_ALIGN(E)
      + PAGE_ALIGN(E)
      
      @@
      expression E;
      @@
      - page_cache_get(E)
      + get_page(E)
      
      @@
      expression E;
      @@
      - page_cache_release(E)
      + put_page(E)
      Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      09cbfeaf
  2. 16 Feb, 2015 1 commit
  3. 30 Nov, 2014 1 commit
  4. 17 Sep, 2014 1 commit
  5. 09 Jun, 2014 1 commit
    • Zach Brown's avatar
      btrfs: return errno instead of -1 from compression · 60e1975a
      Zach Brown authored
      The compression layer seems to have been built to return -1 and have
      callers make up errors that make sense.  This isn't great because there
      are different errors that originate down in the compression layer.
      
      Let's return real negative errnos from the compression layer so that
      callers can pass on the error without having to guess what happened.
      ENOMEM for allocation failure, E2BIG when compression exceeds the
      uncompressed input, and EIO for everything else.
      
      This helps a future path return errors from btrfs_decompress().
      Signed-off-by: default avatarZach Brown <zab@redhat.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      60e1975a
  6. 28 Jan, 2014 1 commit
  7. 01 Sep, 2013 1 commit
  8. 01 Jul, 2013 1 commit
  9. 20 Mar, 2012 1 commit
  10. 16 Feb, 2011 1 commit
  11. 22 Dec, 2010 2 commits
    • Li Zefan's avatar
      btrfs: Extract duplicate decompress code · 3a39c18d
      Li Zefan authored
      Add a common function to copy decompressed data from working buffer
      to bio pages.
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      3a39c18d
    • Li Zefan's avatar
      btrfs: Add lzo compression support · a6fa6fae
      Li Zefan authored
      Lzo is a much faster compression algorithm than gzib, so would allow
      more users to enable transparent compression, and some users can
      choose from compression ratio and speed for different applications
      
      Usage:
      
       # mount -t btrfs -o compress[=<zlib,lzo>] dev /mnt
      or
       # mount -t btrfs -o compress-force[=<zlib,lzo>] dev /mnt
      
      "-o compress" without argument is still allowed for compatability.
      
      Compatibility:
      
      If we mount a filesystem with lzo compression, it will not be able be
      mounted in old kernels. One reason is, otherwise btrfs will directly
      dump compressed data, which sits in inline extent, to user.
      
      Performance:
      
      The test copied a linux source tarball (~400M) from an ext4 partition
      to the btrfs partition, and then extracted it.
      
      (time in second)
                 lzo        zlib        nocompress
      copy:      10.6       21.7        14.9
      extract:   70.1       94.4        66.6
      
      (data size in MB)
                 lzo        zlib        nocompress
      copy:      185.87     108.69      394.49
      extract:   193.80     132.36      381.21
      
      Changelog:
      
      v1 -> v2:
      - Select LZO_COMPRESS and LZO_DECOMPRESS in btrfs Kconfig.
      - Add incompability flag.
      - Fix error handling in compress code.
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      a6fa6fae