Revision 1c1e093cbf6d3a7576ba0bd10363362a1c5c74ee authored by Stefan Weinhuber on 12 May 2010, 07:32:11 UTC, committed by Martin Schwidefsky on 12 May 2010, 07:32:26 UTC
The various dasd_sleep_on functions use a global wait queue when waiting for a cqr. The wait condition checks the status and devlist fields of the cqr to determine if it is safe to continue. This evaluation may return true, although the tasklet has not finished processing of the cqr and the callback function has not been called yet. When the callback is finally called, the data in the cqr may already be invalid. The sleep_on wait condition needs a safe way to determine if the tasklet has finished processing. Use the callback_data field of the cqr to store a token, which is set by the callback function itself. Cc: <stable@kernel.org> Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 parent cea0d76
failslab.c
#include <linux/fault-inject.h>
#include <linux/slab.h>
static struct {
struct fault_attr attr;
u32 ignore_gfp_wait;
int cache_filter;
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
struct dentry *ignore_gfp_wait_file;
struct dentry *cache_filter_file;
#endif
} failslab = {
.attr = FAULT_ATTR_INITIALIZER,
.ignore_gfp_wait = 1,
.cache_filter = 0,
};
bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
{
if (gfpflags & __GFP_NOFAIL)
return false;
if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
return false;
if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
return false;
return should_fail(&failslab.attr, size);
}
static int __init setup_failslab(char *str)
{
return setup_fault_attr(&failslab.attr, str);
}
__setup("failslab=", setup_failslab);
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
static int __init failslab_debugfs_init(void)
{
mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
struct dentry *dir;
int err;
err = init_fault_attr_dentries(&failslab.attr, "failslab");
if (err)
return err;
dir = failslab.attr.dentries.dir;
failslab.ignore_gfp_wait_file =
debugfs_create_bool("ignore-gfp-wait", mode, dir,
&failslab.ignore_gfp_wait);
failslab.cache_filter_file =
debugfs_create_bool("cache-filter", mode, dir,
&failslab.cache_filter);
if (!failslab.ignore_gfp_wait_file ||
!failslab.cache_filter_file) {
err = -ENOMEM;
debugfs_remove(failslab.cache_filter_file);
debugfs_remove(failslab.ignore_gfp_wait_file);
cleanup_fault_attr_dentries(&failslab.attr);
}
return err;
}
late_initcall(failslab_debugfs_init);
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
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