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| author | Jerome Marchand <jmarchan@redhat.com> | 2011-06-10 13:28:48 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-07-05 17:07:13 (GMT) |
| commit | 924bd88d703e53d30f393fac6117f8f1bc79aab6 (patch) | |
| tree | 223f2de31c371175a8f96faeb0b27ff1f5789875 /drivers/staging/zram/zram_drv.h | |
| parent | 8c921b2b43d47faa7c11eac1d2673bbe7fbc41dc (diff) | |
| download | linux-fsl-qoriq-924bd88d703e53d30f393fac6117f8f1bc79aab6.tar.xz | |
Staging: zram: allow partial page operations
Commit 7b19b8d45b216ff3186f066b31937bdbde066f08 (zram: Prevent overflow
in logical block size) introduced ZRAM_LOGICAL_BLOCK_SIZE constant to
prevent overflow of logical block size on 64k page kernel.
However, the current implementation of zram only allow operation on block
of the same size as a page. That makes theorically legit 4k requests fail
on 64k page kernel.
This patch makes zram allow operation on partial pages. Basically, it
means we still do operations on full pages internally, but only copy the
relevent segments from/to the user memory.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/zram/zram_drv.h')
| -rw-r--r-- | drivers/staging/zram/zram_drv.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h index 408b2c0..8acf9eb 100644 --- a/drivers/staging/zram/zram_drv.h +++ b/drivers/staging/zram/zram_drv.h @@ -61,7 +61,10 @@ static const unsigned max_zpage_size = PAGE_SIZE / 4 * 3; #define SECTOR_SIZE (1 << SECTOR_SHIFT) #define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) #define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) -#define ZRAM_LOGICAL_BLOCK_SIZE 4096 +#define ZRAM_LOGICAL_BLOCK_SHIFT 12 +#define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT) +#define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ + (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) /* Flags for zram pages (table[page_no].flags) */ enum zram_pageflags { |