lkml.org 
[lkml]   [2019]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 01/11] btrfs: add macros for compression type and level
    On Mon, Jan 28, 2019 at 04:24:27PM -0500, Dennis Zhou wrote:
    > It is very easy to miss places that rely on a certain bitshifting for
    > decyphering the type_level overloading. Make macros handle this instead.
    >
    > Signed-off-by: Dennis Zhou <dennis@kernel.org>
    > ---
    > fs/btrfs/compression.c | 2 +-
    > fs/btrfs/compression.h | 3 +++
    > fs/btrfs/zlib.c | 2 +-
    > 3 files changed, 5 insertions(+), 2 deletions(-)
    >
    > diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
    > index 548057630b69..586f95ac0aea 100644
    > --- a/fs/btrfs/compression.c
    > +++ b/fs/btrfs/compression.c
    > @@ -1036,9 +1036,9 @@ int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
    > unsigned long *total_in,
    > unsigned long *total_out)
    > {
    > + int type = BTRFS_COMPRESS_TYPE(type_level);
    > struct list_head *workspace;
    > int ret;
    > - int type = type_level & 0xF;
    >
    > workspace = find_workspace(type);
    >
    > diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
    > index ddda9b80bf20..69a9197dadc3 100644
    > --- a/fs/btrfs/compression.h
    > +++ b/fs/btrfs/compression.h
    > @@ -25,6 +25,9 @@
    >
    > #define BTRFS_ZLIB_DEFAULT_LEVEL 3
    >
    > +#define BTRFS_COMPRESS_TYPE(type_level) (type_level & 0xF)
    > +#define BTRFS_COMPRESS_LEVEL(type_level) ((type_level & 0xF0) >> 4)

    Nit: these can be inline functions rather than macros.

    > struct compressed_bio {
    > /* number of bios pending for this compressed extent */
    > refcount_t pending_bios;
    > diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
    > index 970ff3e35bb3..1480b3eee306 100644
    > --- a/fs/btrfs/zlib.c
    > +++ b/fs/btrfs/zlib.c
    > @@ -393,7 +393,7 @@ static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
    > static void zlib_set_level(struct list_head *ws, unsigned int type)
    > {
    > struct workspace *workspace = list_entry(ws, struct workspace, list);
    > - unsigned level = (type & 0xF0) >> 4;
    > + unsigned int level = BTRFS_COMPRESS_LEVEL(type);
    >
    > if (level > 9)
    > level = 9;
    > --
    > 2.17.1
    >

    \
     
     \ /
      Last update: 2019-01-29 23:31    [W:4.040 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site