From 68408632cfd94728bd1d8ef97aada9b60346dfcf Mon Sep 17 00:00:00 2001 From: Sami Tolvanen <samitolvanen@google.com> Date: Wed, 30 Mar 2016 14:10:13 -0700 Subject: [PATCH] ANDROID: dm: verity-fec: add sysfs attribute fec/corrected Add a sysfs entry that allows user space to determine whether dm-verity has come across correctable errors on the underlying block device. Bug: 22655252 Bug: 27928374 Change-Id: I80547a2aa944af2fb9ffde002650482877ade31b Signed-off-by: Sami Tolvanen <samitolvanen@google.com> (cherry picked from commit 7911fad5f0a2cf5afc2215657219a21e6630e001) [AmitP: Folded following android-4.9 commit changes into this patch 3278f53e4658 ("ANDROID: dm verity fec: add missing release from fec_ktype")] Signed-off-by: Amit Pundir <amit.pundir@linaro.org> --- drivers/md/dm-verity-fec.c | 46 +++++++++++++++++++++++++++++++++++++- drivers/md/dm-verity-fec.h | 4 ++++ 2 files changed, 49 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c index e13f90832b6b..776a4f77f76c 100644 --- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -11,6 +11,7 @@ #include "dm-verity-fec.h" #include <linux/math64.h> +#include <linux/sysfs.h> #define DM_MSG_PREFIX "verity-fec" @@ -175,9 +176,11 @@ error: if (r < 0 && neras) DMERR_LIMIT("%s: FEC %llu: failed to correct: %d", v->data_dev->name, (unsigned long long)rsb, r); - else if (r > 0) + else if (r > 0) { DMWARN_LIMIT("%s: FEC %llu: corrected %d errors", v->data_dev->name, (unsigned long long)rsb, r); + atomic_add_unless(&v->fec->corrected, 1, INT_MAX); + } return r; } @@ -545,6 +548,7 @@ unsigned verity_fec_status_table(struct dm_verity *v, unsigned sz, void verity_fec_dtr(struct dm_verity *v) { struct dm_verity_fec *f = v->fec; + struct kobject *kobj = &f->kobj_holder.kobj; if (!verity_fec_is_enabled(v)) goto out; @@ -561,6 +565,12 @@ void verity_fec_dtr(struct dm_verity *v) if (f->dev) dm_put_device(v->ti, f->dev); + + if (kobj->state_initialized) { + kobject_put(kobj); + wait_for_completion(dm_get_completion_from_kobject(kobj)); + } + out: kfree(f); v->fec = NULL; @@ -649,6 +659,28 @@ int verity_fec_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, return 0; } +static ssize_t corrected_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + struct dm_verity_fec *f = container_of(kobj, struct dm_verity_fec, + kobj_holder.kobj); + + return sprintf(buf, "%d\n", atomic_read(&f->corrected)); +} + +static struct kobj_attribute attr_corrected = __ATTR_RO(corrected); + +static struct attribute *fec_attrs[] = { + &attr_corrected.attr, + NULL +}; + +static struct kobj_type fec_ktype = { + .sysfs_ops = &kobj_sysfs_ops, + .default_attrs = fec_attrs, + .release = dm_kobject_release +}; + /* * Allocate dm_verity_fec for v->fec. Must be called before verity_fec_ctr. */ @@ -672,8 +704,10 @@ int verity_fec_ctr_alloc(struct dm_verity *v) */ int verity_fec_ctr(struct dm_verity *v) { + int r; struct dm_verity_fec *f = v->fec; struct dm_target *ti = v->ti; + struct mapped_device *md = dm_table_get_md(ti->table); u64 hash_blocks; if (!verity_fec_is_enabled(v)) { @@ -681,6 +715,16 @@ int verity_fec_ctr(struct dm_verity *v) return 0; } + /* Create a kobject and sysfs attributes */ + init_completion(&f->kobj_holder.completion); + + r = kobject_init_and_add(&f->kobj_holder.kobj, &fec_ktype, + &disk_to_dev(dm_disk(md))->kobj, "%s", "fec"); + if (r) { + ti->error = "Cannot create kobject"; + return r; + } + /* * FEC is computed over data blocks, possible metadata, and * hash blocks. In other words, FEC covers total of fec_blocks diff --git a/drivers/md/dm-verity-fec.h b/drivers/md/dm-verity-fec.h index bb31ce87a933..4db0cae262eb 100644 --- a/drivers/md/dm-verity-fec.h +++ b/drivers/md/dm-verity-fec.h @@ -12,6 +12,8 @@ #ifndef DM_VERITY_FEC_H #define DM_VERITY_FEC_H +#include "dm.h" +#include "dm-core.h" #include "dm-verity.h" #include <linux/rslib.h> @@ -51,6 +53,8 @@ struct dm_verity_fec { mempool_t *extra_pool; /* mempool for extra buffers */ mempool_t *output_pool; /* mempool for output */ struct kmem_cache *cache; /* cache for buffers */ + atomic_t corrected; /* corrected errors */ + struct dm_kobject_holder kobj_holder; /* for sysfs attributes */ }; /* per-bio data */ -- 2.20.1