Jerome Marchand c5bde2388e Staging: zram: Replace mutex lock by a R/W semaphore ... Currently, nothing protects zram table from concurrent access. For instance, ZRAM_UNCOMPRESSED bit can be cleared by zram_free_page() called from a concurrent write between the time ZRAM_UNCOMPRESSED has been set and the time it is tested to unmap KM_USER0 in zram_bvec_write(). This ultimately leads to kernel panic. Also, a read request can occurs when the page has been freed by a running write request and before it has been updated, leading to zero filled block being incorrectly read and "Read before write" error message. This patch replace the current mutex by a rw_semaphore. It extends the protection to zram table (currently, only compression buffers are protected) and read requests (currently, only write requests are protected). Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-07-05 10:07:13 -07:00
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Kconfig	staging: Allow sharing xvmalloc for zram and zcache	2011-02-23 14:02:56 -08:00
Makefile	staging: Allow sharing xvmalloc for zram and zcache	2011-02-23 14:02:56 -08:00
xvmalloc_int.h
xvmalloc.c	staging: Allow sharing xvmalloc for zram and zcache	2011-02-23 14:02:56 -08:00
xvmalloc.h
zram_drv.c	Staging: zram: Replace mutex lock by a R/W semaphore	2011-07-05 10:07:13 -07:00
zram_drv.h	Staging: zram: Replace mutex lock by a R/W semaphore	2011-07-05 10:07:13 -07:00
zram_sysfs.c
zram.txt