4c13dd3b48
This patch allow to inject faults only for specific slabs. In order to preserve default behavior cache filter is off by default (all caches are faulty). One may define specific set of slabs like this: # mark skbuff_head_cache as faulty echo 1 > /sys/kernel/slab/skbuff_head_cache/failslab # Turn on cache filter (off by default) echo 1 > /sys/kernel/debug/failslab/cache-filter # Turn on fault injection echo 1 > /sys/kernel/debug/failslab/times echo 1 > /sys/kernel/debug/failslab/probability Acked-by: David Rientjes <rientjes@google.com> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
73 lines
1.7 KiB
C
73 lines
1.7 KiB
C
#include <linux/fault-inject.h>
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#include <linux/gfp.h>
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#include <linux/slab.h>
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static struct {
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struct fault_attr attr;
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u32 ignore_gfp_wait;
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int cache_filter;
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#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
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struct dentry *ignore_gfp_wait_file;
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struct dentry *cache_filter_file;
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#endif
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} failslab = {
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.attr = FAULT_ATTR_INITIALIZER,
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.ignore_gfp_wait = 1,
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.cache_filter = 0,
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};
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bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
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{
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if (gfpflags & __GFP_NOFAIL)
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return false;
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if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
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return false;
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if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
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return false;
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return should_fail(&failslab.attr, size);
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}
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static int __init setup_failslab(char *str)
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{
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return setup_fault_attr(&failslab.attr, str);
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}
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__setup("failslab=", setup_failslab);
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#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
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static int __init failslab_debugfs_init(void)
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{
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mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
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struct dentry *dir;
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int err;
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err = init_fault_attr_dentries(&failslab.attr, "failslab");
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if (err)
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return err;
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dir = failslab.attr.dentries.dir;
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failslab.ignore_gfp_wait_file =
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debugfs_create_bool("ignore-gfp-wait", mode, dir,
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&failslab.ignore_gfp_wait);
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failslab.cache_filter_file =
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debugfs_create_bool("cache-filter", mode, dir,
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&failslab.cache_filter);
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if (!failslab.ignore_gfp_wait_file ||
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!failslab.cache_filter_file) {
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err = -ENOMEM;
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debugfs_remove(failslab.cache_filter_file);
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debugfs_remove(failslab.ignore_gfp_wait_file);
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cleanup_fault_attr_dentries(&failslab.attr);
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}
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return err;
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}
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late_initcall(failslab_debugfs_init);
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#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
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