linux-stable/drivers/nvdimm/btt.c
Vishal Verma 9dedc73a46 libnvdimm/btt: Fix LBA masking during 'free list' population
The Linux BTT implementation assumes that log entries will never have
the 'zero' flag set, and indeed it never sets that flag for log entries
itself.

However, the UEFI spec is ambiguous on the exact format of the LBA field
of a log entry, specifically as to whether it should include the
additional flag bits or not. While a zero bit doesn't make sense in the
context of a log entry, other BTT implementations might still have it set.

If an implementation does happen to have it set, we would happily read
it in as the next block to write to for writes. Since a high bit is set,
it pushes the block number out of the range of an 'arena', and we fail
such a write with an EIO.

Follow the robustness principle, and tolerate such implementations by
stripping out the zero flag when populating the free list during
initialization. Additionally, use the same stripped out entries for
detection of incomplete writes and map restoration that happens at this
stage.

Add a sysfs file 'log_zero_flags' that indicates the ability to accept
such a layout to userspace applications. This enables 'ndctl
check-namespace' to recognize whether the kernel is able to handle zero
flags, or whether it should attempt a fix-up under the --repair option.

Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: Dexuan Cui <decui@microsoft.com>
Reported-by: Pedro d'Aquino Filocre F S Barbuda <pbarbuda@microsoft.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-02-28 09:57:39 -08:00

1753 lines
43 KiB
C

/*
* Block Translation Table
* Copyright (c) 2014-2015, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/highmem.h>
#include <linux/debugfs.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/hdreg.h>
#include <linux/genhd.h>
#include <linux/sizes.h>
#include <linux/ndctl.h>
#include <linux/fs.h>
#include <linux/nd.h>
#include <linux/backing-dev.h>
#include "btt.h"
#include "nd.h"
enum log_ent_request {
LOG_NEW_ENT = 0,
LOG_OLD_ENT
};
static struct device *to_dev(struct arena_info *arena)
{
return &arena->nd_btt->dev;
}
static u64 adjust_initial_offset(struct nd_btt *nd_btt, u64 offset)
{
return offset + nd_btt->initial_offset;
}
static int arena_read_bytes(struct arena_info *arena, resource_size_t offset,
void *buf, size_t n, unsigned long flags)
{
struct nd_btt *nd_btt = arena->nd_btt;
struct nd_namespace_common *ndns = nd_btt->ndns;
/* arena offsets may be shifted from the base of the device */
offset = adjust_initial_offset(nd_btt, offset);
return nvdimm_read_bytes(ndns, offset, buf, n, flags);
}
static int arena_write_bytes(struct arena_info *arena, resource_size_t offset,
void *buf, size_t n, unsigned long flags)
{
struct nd_btt *nd_btt = arena->nd_btt;
struct nd_namespace_common *ndns = nd_btt->ndns;
/* arena offsets may be shifted from the base of the device */
offset = adjust_initial_offset(nd_btt, offset);
return nvdimm_write_bytes(ndns, offset, buf, n, flags);
}
static int btt_info_write(struct arena_info *arena, struct btt_sb *super)
{
int ret;
/*
* infooff and info2off should always be at least 512B aligned.
* We rely on that to make sure rw_bytes does error clearing
* correctly, so make sure that is the case.
*/
dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->infooff, 512),
"arena->infooff: %#llx is unaligned\n", arena->infooff);
dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->info2off, 512),
"arena->info2off: %#llx is unaligned\n", arena->info2off);
ret = arena_write_bytes(arena, arena->info2off, super,
sizeof(struct btt_sb), 0);
if (ret)
return ret;
return arena_write_bytes(arena, arena->infooff, super,
sizeof(struct btt_sb), 0);
}
static int btt_info_read(struct arena_info *arena, struct btt_sb *super)
{
return arena_read_bytes(arena, arena->infooff, super,
sizeof(struct btt_sb), 0);
}
/*
* 'raw' version of btt_map write
* Assumptions:
* mapping is in little-endian
* mapping contains 'E' and 'Z' flags as desired
*/
static int __btt_map_write(struct arena_info *arena, u32 lba, __le32 mapping,
unsigned long flags)
{
u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
if (unlikely(lba >= arena->external_nlba))
dev_err_ratelimited(to_dev(arena),
"%s: lba %#x out of range (max: %#x)\n",
__func__, lba, arena->external_nlba);
return arena_write_bytes(arena, ns_off, &mapping, MAP_ENT_SIZE, flags);
}
static int btt_map_write(struct arena_info *arena, u32 lba, u32 mapping,
u32 z_flag, u32 e_flag, unsigned long rwb_flags)
{
u32 ze;
__le32 mapping_le;
/*
* This 'mapping' is supposed to be just the LBA mapping, without
* any flags set, so strip the flag bits.
*/
mapping = ent_lba(mapping);
ze = (z_flag << 1) + e_flag;
switch (ze) {
case 0:
/*
* We want to set neither of the Z or E flags, and
* in the actual layout, this means setting the bit
* positions of both to '1' to indicate a 'normal'
* map entry
*/
mapping |= MAP_ENT_NORMAL;
break;
case 1:
mapping |= (1 << MAP_ERR_SHIFT);
break;
case 2:
mapping |= (1 << MAP_TRIM_SHIFT);
break;
default:
/*
* The case where Z and E are both sent in as '1' could be
* construed as a valid 'normal' case, but we decide not to,
* to avoid confusion
*/
dev_err_ratelimited(to_dev(arena),
"Invalid use of Z and E flags\n");
return -EIO;
}
mapping_le = cpu_to_le32(mapping);
return __btt_map_write(arena, lba, mapping_le, rwb_flags);
}
static int btt_map_read(struct arena_info *arena, u32 lba, u32 *mapping,
int *trim, int *error, unsigned long rwb_flags)
{
int ret;
__le32 in;
u32 raw_mapping, postmap, ze, z_flag, e_flag;
u64 ns_off = arena->mapoff + (lba * MAP_ENT_SIZE);
if (unlikely(lba >= arena->external_nlba))
dev_err_ratelimited(to_dev(arena),
"%s: lba %#x out of range (max: %#x)\n",
__func__, lba, arena->external_nlba);
ret = arena_read_bytes(arena, ns_off, &in, MAP_ENT_SIZE, rwb_flags);
if (ret)
return ret;
raw_mapping = le32_to_cpu(in);
z_flag = ent_z_flag(raw_mapping);
e_flag = ent_e_flag(raw_mapping);
ze = (z_flag << 1) + e_flag;
postmap = ent_lba(raw_mapping);
/* Reuse the {z,e}_flag variables for *trim and *error */
z_flag = 0;
e_flag = 0;
switch (ze) {
case 0:
/* Initial state. Return postmap = premap */
*mapping = lba;
break;
case 1:
*mapping = postmap;
e_flag = 1;
break;
case 2:
*mapping = postmap;
z_flag = 1;
break;
case 3:
*mapping = postmap;
break;
default:
return -EIO;
}
if (trim)
*trim = z_flag;
if (error)
*error = e_flag;
return ret;
}
static int btt_log_group_read(struct arena_info *arena, u32 lane,
struct log_group *log)
{
return arena_read_bytes(arena,
arena->logoff + (lane * LOG_GRP_SIZE), log,
LOG_GRP_SIZE, 0);
}
static struct dentry *debugfs_root;
static void arena_debugfs_init(struct arena_info *a, struct dentry *parent,
int idx)
{
char dirname[32];
struct dentry *d;
/* If for some reason, parent bttN was not created, exit */
if (!parent)
return;
snprintf(dirname, 32, "arena%d", idx);
d = debugfs_create_dir(dirname, parent);
if (IS_ERR_OR_NULL(d))
return;
a->debugfs_dir = d;
debugfs_create_x64("size", S_IRUGO, d, &a->size);
debugfs_create_x64("external_lba_start", S_IRUGO, d,
&a->external_lba_start);
debugfs_create_x32("internal_nlba", S_IRUGO, d, &a->internal_nlba);
debugfs_create_u32("internal_lbasize", S_IRUGO, d,
&a->internal_lbasize);
debugfs_create_x32("external_nlba", S_IRUGO, d, &a->external_nlba);
debugfs_create_u32("external_lbasize", S_IRUGO, d,
&a->external_lbasize);
debugfs_create_u32("nfree", S_IRUGO, d, &a->nfree);
debugfs_create_u16("version_major", S_IRUGO, d, &a->version_major);
debugfs_create_u16("version_minor", S_IRUGO, d, &a->version_minor);
debugfs_create_x64("nextoff", S_IRUGO, d, &a->nextoff);
debugfs_create_x64("infooff", S_IRUGO, d, &a->infooff);
debugfs_create_x64("dataoff", S_IRUGO, d, &a->dataoff);
debugfs_create_x64("mapoff", S_IRUGO, d, &a->mapoff);
debugfs_create_x64("logoff", S_IRUGO, d, &a->logoff);
debugfs_create_x64("info2off", S_IRUGO, d, &a->info2off);
debugfs_create_x32("flags", S_IRUGO, d, &a->flags);
debugfs_create_u32("log_index_0", S_IRUGO, d, &a->log_index[0]);
debugfs_create_u32("log_index_1", S_IRUGO, d, &a->log_index[1]);
}
static void btt_debugfs_init(struct btt *btt)
{
int i = 0;
struct arena_info *arena;
btt->debugfs_dir = debugfs_create_dir(dev_name(&btt->nd_btt->dev),
debugfs_root);
if (IS_ERR_OR_NULL(btt->debugfs_dir))
return;
list_for_each_entry(arena, &btt->arena_list, list) {
arena_debugfs_init(arena, btt->debugfs_dir, i);
i++;
}
}
static u32 log_seq(struct log_group *log, int log_idx)
{
return le32_to_cpu(log->ent[log_idx].seq);
}
/*
* This function accepts two log entries, and uses the
* sequence number to find the 'older' entry.
* It also updates the sequence number in this old entry to
* make it the 'new' one if the mark_flag is set.
* Finally, it returns which of the entries was the older one.
*
* TODO The logic feels a bit kludge-y. make it better..
*/
static int btt_log_get_old(struct arena_info *a, struct log_group *log)
{
int idx0 = a->log_index[0];
int idx1 = a->log_index[1];
int old;
/*
* the first ever time this is seen, the entry goes into [0]
* the next time, the following logic works out to put this
* (next) entry into [1]
*/
if (log_seq(log, idx0) == 0) {
log->ent[idx0].seq = cpu_to_le32(1);
return 0;
}
if (log_seq(log, idx0) == log_seq(log, idx1))
return -EINVAL;
if (log_seq(log, idx0) + log_seq(log, idx1) > 5)
return -EINVAL;
if (log_seq(log, idx0) < log_seq(log, idx1)) {
if ((log_seq(log, idx1) - log_seq(log, idx0)) == 1)
old = 0;
else
old = 1;
} else {
if ((log_seq(log, idx0) - log_seq(log, idx1)) == 1)
old = 1;
else
old = 0;
}
return old;
}
/*
* This function copies the desired (old/new) log entry into ent if
* it is not NULL. It returns the sub-slot number (0 or 1)
* where the desired log entry was found. Negative return values
* indicate errors.
*/
static int btt_log_read(struct arena_info *arena, u32 lane,
struct log_entry *ent, int old_flag)
{
int ret;
int old_ent, ret_ent;
struct log_group log;
ret = btt_log_group_read(arena, lane, &log);
if (ret)
return -EIO;
old_ent = btt_log_get_old(arena, &log);
if (old_ent < 0 || old_ent > 1) {
dev_err(to_dev(arena),
"log corruption (%d): lane %d seq [%d, %d]\n",
old_ent, lane, log.ent[arena->log_index[0]].seq,
log.ent[arena->log_index[1]].seq);
/* TODO set error state? */
return -EIO;
}
ret_ent = (old_flag ? old_ent : (1 - old_ent));
if (ent != NULL)
memcpy(ent, &log.ent[arena->log_index[ret_ent]], LOG_ENT_SIZE);
return ret_ent;
}
/*
* This function commits a log entry to media
* It does _not_ prepare the freelist entry for the next write
* btt_flog_write is the wrapper for updating the freelist elements
*/
static int __btt_log_write(struct arena_info *arena, u32 lane,
u32 sub, struct log_entry *ent, unsigned long flags)
{
int ret;
u32 group_slot = arena->log_index[sub];
unsigned int log_half = LOG_ENT_SIZE / 2;
void *src = ent;
u64 ns_off;
ns_off = arena->logoff + (lane * LOG_GRP_SIZE) +
(group_slot * LOG_ENT_SIZE);
/* split the 16B write into atomic, durable halves */
ret = arena_write_bytes(arena, ns_off, src, log_half, flags);
if (ret)
return ret;
ns_off += log_half;
src += log_half;
return arena_write_bytes(arena, ns_off, src, log_half, flags);
}
static int btt_flog_write(struct arena_info *arena, u32 lane, u32 sub,
struct log_entry *ent)
{
int ret;
ret = __btt_log_write(arena, lane, sub, ent, NVDIMM_IO_ATOMIC);
if (ret)
return ret;
/* prepare the next free entry */
arena->freelist[lane].sub = 1 - arena->freelist[lane].sub;
if (++(arena->freelist[lane].seq) == 4)
arena->freelist[lane].seq = 1;
if (ent_e_flag(ent->old_map))
arena->freelist[lane].has_err = 1;
arena->freelist[lane].block = le32_to_cpu(ent_lba(ent->old_map));
return ret;
}
/*
* This function initializes the BTT map to the initial state, which is
* all-zeroes, and indicates an identity mapping
*/
static int btt_map_init(struct arena_info *arena)
{
int ret = -EINVAL;
void *zerobuf;
size_t offset = 0;
size_t chunk_size = SZ_2M;
size_t mapsize = arena->logoff - arena->mapoff;
zerobuf = kzalloc(chunk_size, GFP_KERNEL);
if (!zerobuf)
return -ENOMEM;
/*
* mapoff should always be at least 512B aligned. We rely on that to
* make sure rw_bytes does error clearing correctly, so make sure that
* is the case.
*/
dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->mapoff, 512),
"arena->mapoff: %#llx is unaligned\n", arena->mapoff);
while (mapsize) {
size_t size = min(mapsize, chunk_size);
dev_WARN_ONCE(to_dev(arena), size < 512,
"chunk size: %#zx is unaligned\n", size);
ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf,
size, 0);
if (ret)
goto free;
offset += size;
mapsize -= size;
cond_resched();
}
free:
kfree(zerobuf);
return ret;
}
/*
* This function initializes the BTT log with 'fake' entries pointing
* to the initial reserved set of blocks as being free
*/
static int btt_log_init(struct arena_info *arena)
{
size_t logsize = arena->info2off - arena->logoff;
size_t chunk_size = SZ_4K, offset = 0;
struct log_entry ent;
void *zerobuf;
int ret;
u32 i;
zerobuf = kzalloc(chunk_size, GFP_KERNEL);
if (!zerobuf)
return -ENOMEM;
/*
* logoff should always be at least 512B aligned. We rely on that to
* make sure rw_bytes does error clearing correctly, so make sure that
* is the case.
*/
dev_WARN_ONCE(to_dev(arena), !IS_ALIGNED(arena->logoff, 512),
"arena->logoff: %#llx is unaligned\n", arena->logoff);
while (logsize) {
size_t size = min(logsize, chunk_size);
dev_WARN_ONCE(to_dev(arena), size < 512,
"chunk size: %#zx is unaligned\n", size);
ret = arena_write_bytes(arena, arena->logoff + offset, zerobuf,
size, 0);
if (ret)
goto free;
offset += size;
logsize -= size;
cond_resched();
}
for (i = 0; i < arena->nfree; i++) {
ent.lba = cpu_to_le32(i);
ent.old_map = cpu_to_le32(arena->external_nlba + i);
ent.new_map = cpu_to_le32(arena->external_nlba + i);
ent.seq = cpu_to_le32(LOG_SEQ_INIT);
ret = __btt_log_write(arena, i, 0, &ent, 0);
if (ret)
goto free;
}
free:
kfree(zerobuf);
return ret;
}
static u64 to_namespace_offset(struct arena_info *arena, u64 lba)
{
return arena->dataoff + ((u64)lba * arena->internal_lbasize);
}
static int arena_clear_freelist_error(struct arena_info *arena, u32 lane)
{
int ret = 0;
if (arena->freelist[lane].has_err) {
void *zero_page = page_address(ZERO_PAGE(0));
u32 lba = arena->freelist[lane].block;
u64 nsoff = to_namespace_offset(arena, lba);
unsigned long len = arena->sector_size;
mutex_lock(&arena->err_lock);
while (len) {
unsigned long chunk = min(len, PAGE_SIZE);
ret = arena_write_bytes(arena, nsoff, zero_page,
chunk, 0);
if (ret)
break;
len -= chunk;
nsoff += chunk;
if (len == 0)
arena->freelist[lane].has_err = 0;
}
mutex_unlock(&arena->err_lock);
}
return ret;
}
static int btt_freelist_init(struct arena_info *arena)
{
int new, ret;
struct log_entry log_new;
u32 i, map_entry, log_oldmap, log_newmap;
arena->freelist = kcalloc(arena->nfree, sizeof(struct free_entry),
GFP_KERNEL);
if (!arena->freelist)
return -ENOMEM;
for (i = 0; i < arena->nfree; i++) {
new = btt_log_read(arena, i, &log_new, LOG_NEW_ENT);
if (new < 0)
return new;
/* old and new map entries with any flags stripped out */
log_oldmap = ent_lba(le32_to_cpu(log_new.old_map));
log_newmap = ent_lba(le32_to_cpu(log_new.new_map));
/* sub points to the next one to be overwritten */
arena->freelist[i].sub = 1 - new;
arena->freelist[i].seq = nd_inc_seq(le32_to_cpu(log_new.seq));
arena->freelist[i].block = log_oldmap;
/*
* FIXME: if error clearing fails during init, we want to make
* the BTT read-only
*/
if (ent_e_flag(log_new.old_map) &&
!ent_normal(log_new.old_map)) {
arena->freelist[i].has_err = 1;
ret = arena_clear_freelist_error(arena, i);
if (ret)
dev_err_ratelimited(to_dev(arena),
"Unable to clear known errors\n");
}
/* This implies a newly created or untouched flog entry */
if (log_oldmap == log_newmap)
continue;
/* Check if map recovery is needed */
ret = btt_map_read(arena, le32_to_cpu(log_new.lba), &map_entry,
NULL, NULL, 0);
if (ret)
return ret;
/*
* The map_entry from btt_read_map is stripped of any flag bits,
* so use the stripped out versions from the log as well for
* testing whether recovery is needed. For restoration, use the
* 'raw' version of the log entries as that captured what we
* were going to write originally.
*/
if ((log_newmap != map_entry) && (log_oldmap == map_entry)) {
/*
* Last transaction wrote the flog, but wasn't able
* to complete the map write. So fix up the map.
*/
ret = btt_map_write(arena, le32_to_cpu(log_new.lba),
le32_to_cpu(log_new.new_map), 0, 0, 0);
if (ret)
return ret;
}
}
return 0;
}
static bool ent_is_padding(struct log_entry *ent)
{
return (ent->lba == 0) && (ent->old_map == 0) && (ent->new_map == 0)
&& (ent->seq == 0);
}
/*
* Detecting valid log indices: We read a log group (see the comments in btt.h
* for a description of a 'log_group' and its 'slots'), and iterate over its
* four slots. We expect that a padding slot will be all-zeroes, and use this
* to detect a padding slot vs. an actual entry.
*
* If a log_group is in the initial state, i.e. hasn't been used since the
* creation of this BTT layout, it will have three of the four slots with
* zeroes. We skip over these log_groups for the detection of log_index. If
* all log_groups are in the initial state (i.e. the BTT has never been
* written to), it is safe to assume the 'new format' of log entries in slots
* (0, 1).
*/
static int log_set_indices(struct arena_info *arena)
{
bool idx_set = false, initial_state = true;
int ret, log_index[2] = {-1, -1};
u32 i, j, next_idx = 0;
struct log_group log;
u32 pad_count = 0;
for (i = 0; i < arena->nfree; i++) {
ret = btt_log_group_read(arena, i, &log);
if (ret < 0)
return ret;
for (j = 0; j < 4; j++) {
if (!idx_set) {
if (ent_is_padding(&log.ent[j])) {
pad_count++;
continue;
} else {
/* Skip if index has been recorded */
if ((next_idx == 1) &&
(j == log_index[0]))
continue;
/* valid entry, record index */
log_index[next_idx] = j;
next_idx++;
}
if (next_idx == 2) {
/* two valid entries found */
idx_set = true;
} else if (next_idx > 2) {
/* too many valid indices */
return -ENXIO;
}
} else {
/*
* once the indices have been set, just verify
* that all subsequent log groups are either in
* their initial state or follow the same
* indices.
*/
if (j == log_index[0]) {
/* entry must be 'valid' */
if (ent_is_padding(&log.ent[j]))
return -ENXIO;
} else if (j == log_index[1]) {
;
/*
* log_index[1] can be padding if the
* lane never got used and it is still
* in the initial state (three 'padding'
* entries)
*/
} else {
/* entry must be invalid (padding) */
if (!ent_is_padding(&log.ent[j]))
return -ENXIO;
}
}
}
/*
* If any of the log_groups have more than one valid,
* non-padding entry, then the we are no longer in the
* initial_state
*/
if (pad_count < 3)
initial_state = false;
pad_count = 0;
}
if (!initial_state && !idx_set)
return -ENXIO;
/*
* If all the entries in the log were in the initial state,
* assume new padding scheme
*/
if (initial_state)
log_index[1] = 1;
/*
* Only allow the known permutations of log/padding indices,
* i.e. (0, 1), and (0, 2)
*/
if ((log_index[0] == 0) && ((log_index[1] == 1) || (log_index[1] == 2)))
; /* known index possibilities */
else {
dev_err(to_dev(arena), "Found an unknown padding scheme\n");
return -ENXIO;
}
arena->log_index[0] = log_index[0];
arena->log_index[1] = log_index[1];
dev_dbg(to_dev(arena), "log_index_0 = %d\n", log_index[0]);
dev_dbg(to_dev(arena), "log_index_1 = %d\n", log_index[1]);
return 0;
}
static int btt_rtt_init(struct arena_info *arena)
{
arena->rtt = kcalloc(arena->nfree, sizeof(u32), GFP_KERNEL);
if (arena->rtt == NULL)
return -ENOMEM;
return 0;
}
static int btt_maplocks_init(struct arena_info *arena)
{
u32 i;
arena->map_locks = kcalloc(arena->nfree, sizeof(struct aligned_lock),
GFP_KERNEL);
if (!arena->map_locks)
return -ENOMEM;
for (i = 0; i < arena->nfree; i++)
spin_lock_init(&arena->map_locks[i].lock);
return 0;
}
static struct arena_info *alloc_arena(struct btt *btt, size_t size,
size_t start, size_t arena_off)
{
struct arena_info *arena;
u64 logsize, mapsize, datasize;
u64 available = size;
arena = kzalloc(sizeof(struct arena_info), GFP_KERNEL);
if (!arena)
return NULL;
arena->nd_btt = btt->nd_btt;
arena->sector_size = btt->sector_size;
mutex_init(&arena->err_lock);
if (!size)
return arena;
arena->size = size;
arena->external_lba_start = start;
arena->external_lbasize = btt->lbasize;
arena->internal_lbasize = roundup(arena->external_lbasize,
INT_LBASIZE_ALIGNMENT);
arena->nfree = BTT_DEFAULT_NFREE;
arena->version_major = btt->nd_btt->version_major;
arena->version_minor = btt->nd_btt->version_minor;
if (available % BTT_PG_SIZE)
available -= (available % BTT_PG_SIZE);
/* Two pages are reserved for the super block and its copy */
available -= 2 * BTT_PG_SIZE;
/* The log takes a fixed amount of space based on nfree */
logsize = roundup(arena->nfree * LOG_GRP_SIZE, BTT_PG_SIZE);
available -= logsize;
/* Calculate optimal split between map and data area */
arena->internal_nlba = div_u64(available - BTT_PG_SIZE,
arena->internal_lbasize + MAP_ENT_SIZE);
arena->external_nlba = arena->internal_nlba - arena->nfree;
mapsize = roundup((arena->external_nlba * MAP_ENT_SIZE), BTT_PG_SIZE);
datasize = available - mapsize;
/* 'Absolute' values, relative to start of storage space */
arena->infooff = arena_off;
arena->dataoff = arena->infooff + BTT_PG_SIZE;
arena->mapoff = arena->dataoff + datasize;
arena->logoff = arena->mapoff + mapsize;
arena->info2off = arena->logoff + logsize;
/* Default log indices are (0,1) */
arena->log_index[0] = 0;
arena->log_index[1] = 1;
return arena;
}
static void free_arenas(struct btt *btt)
{
struct arena_info *arena, *next;
list_for_each_entry_safe(arena, next, &btt->arena_list, list) {
list_del(&arena->list);
kfree(arena->rtt);
kfree(arena->map_locks);
kfree(arena->freelist);
debugfs_remove_recursive(arena->debugfs_dir);
kfree(arena);
}
}
/*
* This function reads an existing valid btt superblock and
* populates the corresponding arena_info struct
*/
static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super,
u64 arena_off)
{
arena->internal_nlba = le32_to_cpu(super->internal_nlba);
arena->internal_lbasize = le32_to_cpu(super->internal_lbasize);
arena->external_nlba = le32_to_cpu(super->external_nlba);
arena->external_lbasize = le32_to_cpu(super->external_lbasize);
arena->nfree = le32_to_cpu(super->nfree);
arena->version_major = le16_to_cpu(super->version_major);
arena->version_minor = le16_to_cpu(super->version_minor);
arena->nextoff = (super->nextoff == 0) ? 0 : (arena_off +
le64_to_cpu(super->nextoff));
arena->infooff = arena_off;
arena->dataoff = arena_off + le64_to_cpu(super->dataoff);
arena->mapoff = arena_off + le64_to_cpu(super->mapoff);
arena->logoff = arena_off + le64_to_cpu(super->logoff);
arena->info2off = arena_off + le64_to_cpu(super->info2off);
arena->size = (le64_to_cpu(super->nextoff) > 0)
? (le64_to_cpu(super->nextoff))
: (arena->info2off - arena->infooff + BTT_PG_SIZE);
arena->flags = le32_to_cpu(super->flags);
}
static int discover_arenas(struct btt *btt)
{
int ret = 0;
struct arena_info *arena;
struct btt_sb *super;
size_t remaining = btt->rawsize;
u64 cur_nlba = 0;
size_t cur_off = 0;
int num_arenas = 0;
super = kzalloc(sizeof(*super), GFP_KERNEL);
if (!super)
return -ENOMEM;
while (remaining) {
/* Alloc memory for arena */
arena = alloc_arena(btt, 0, 0, 0);
if (!arena) {
ret = -ENOMEM;
goto out_super;
}
arena->infooff = cur_off;
ret = btt_info_read(arena, super);
if (ret)
goto out;
if (!nd_btt_arena_is_valid(btt->nd_btt, super)) {
if (remaining == btt->rawsize) {
btt->init_state = INIT_NOTFOUND;
dev_info(to_dev(arena), "No existing arenas\n");
goto out;
} else {
dev_err(to_dev(arena),
"Found corrupted metadata!\n");
ret = -ENODEV;
goto out;
}
}
arena->external_lba_start = cur_nlba;
parse_arena_meta(arena, super, cur_off);
ret = log_set_indices(arena);
if (ret) {
dev_err(to_dev(arena),
"Unable to deduce log/padding indices\n");
goto out;
}
ret = btt_freelist_init(arena);
if (ret)
goto out;
ret = btt_rtt_init(arena);
if (ret)
goto out;
ret = btt_maplocks_init(arena);
if (ret)
goto out;
list_add_tail(&arena->list, &btt->arena_list);
remaining -= arena->size;
cur_off += arena->size;
cur_nlba += arena->external_nlba;
num_arenas++;
if (arena->nextoff == 0)
break;
}
btt->num_arenas = num_arenas;
btt->nlba = cur_nlba;
btt->init_state = INIT_READY;
kfree(super);
return ret;
out:
kfree(arena);
free_arenas(btt);
out_super:
kfree(super);
return ret;
}
static int create_arenas(struct btt *btt)
{
size_t remaining = btt->rawsize;
size_t cur_off = 0;
while (remaining) {
struct arena_info *arena;
size_t arena_size = min_t(u64, ARENA_MAX_SIZE, remaining);
remaining -= arena_size;
if (arena_size < ARENA_MIN_SIZE)
break;
arena = alloc_arena(btt, arena_size, btt->nlba, cur_off);
if (!arena) {
free_arenas(btt);
return -ENOMEM;
}
btt->nlba += arena->external_nlba;
if (remaining >= ARENA_MIN_SIZE)
arena->nextoff = arena->size;
else
arena->nextoff = 0;
cur_off += arena_size;
list_add_tail(&arena->list, &btt->arena_list);
}
return 0;
}
/*
* This function completes arena initialization by writing
* all the metadata.
* It is only called for an uninitialized arena when a write
* to that arena occurs for the first time.
*/
static int btt_arena_write_layout(struct arena_info *arena)
{
int ret;
u64 sum;
struct btt_sb *super;
struct nd_btt *nd_btt = arena->nd_btt;
const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
ret = btt_map_init(arena);
if (ret)
return ret;
ret = btt_log_init(arena);
if (ret)
return ret;
super = kzalloc(sizeof(struct btt_sb), GFP_NOIO);
if (!super)
return -ENOMEM;
strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
memcpy(super->uuid, nd_btt->uuid, 16);
memcpy(super->parent_uuid, parent_uuid, 16);
super->flags = cpu_to_le32(arena->flags);
super->version_major = cpu_to_le16(arena->version_major);
super->version_minor = cpu_to_le16(arena->version_minor);
super->external_lbasize = cpu_to_le32(arena->external_lbasize);
super->external_nlba = cpu_to_le32(arena->external_nlba);
super->internal_lbasize = cpu_to_le32(arena->internal_lbasize);
super->internal_nlba = cpu_to_le32(arena->internal_nlba);
super->nfree = cpu_to_le32(arena->nfree);
super->infosize = cpu_to_le32(sizeof(struct btt_sb));
super->nextoff = cpu_to_le64(arena->nextoff);
/*
* Subtract arena->infooff (arena start) so numbers are relative
* to 'this' arena
*/
super->dataoff = cpu_to_le64(arena->dataoff - arena->infooff);
super->mapoff = cpu_to_le64(arena->mapoff - arena->infooff);
super->logoff = cpu_to_le64(arena->logoff - arena->infooff);
super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
super->flags = 0;
sum = nd_sb_checksum((struct nd_gen_sb *) super);
super->checksum = cpu_to_le64(sum);
ret = btt_info_write(arena, super);
kfree(super);
return ret;
}
/*
* This function completes the initialization for the BTT namespace
* such that it is ready to accept IOs
*/
static int btt_meta_init(struct btt *btt)
{
int ret = 0;
struct arena_info *arena;
mutex_lock(&btt->init_lock);
list_for_each_entry(arena, &btt->arena_list, list) {
ret = btt_arena_write_layout(arena);
if (ret)
goto unlock;
ret = btt_freelist_init(arena);
if (ret)
goto unlock;
ret = btt_rtt_init(arena);
if (ret)
goto unlock;
ret = btt_maplocks_init(arena);
if (ret)
goto unlock;
}
btt->init_state = INIT_READY;
unlock:
mutex_unlock(&btt->init_lock);
return ret;
}
static u32 btt_meta_size(struct btt *btt)
{
return btt->lbasize - btt->sector_size;
}
/*
* This function calculates the arena in which the given LBA lies
* by doing a linear walk. This is acceptable since we expect only
* a few arenas. If we have backing devices that get much larger,
* we can construct a balanced binary tree of arenas at init time
* so that this range search becomes faster.
*/
static int lba_to_arena(struct btt *btt, sector_t sector, __u32 *premap,
struct arena_info **arena)
{
struct arena_info *arena_list;
__u64 lba = div_u64(sector << SECTOR_SHIFT, btt->sector_size);
list_for_each_entry(arena_list, &btt->arena_list, list) {
if (lba < arena_list->external_nlba) {
*arena = arena_list;
*premap = lba;
return 0;
}
lba -= arena_list->external_nlba;
}
return -EIO;
}
/*
* The following (lock_map, unlock_map) are mostly just to improve
* readability, since they index into an array of locks
*/
static void lock_map(struct arena_info *arena, u32 premap)
__acquires(&arena->map_locks[idx].lock)
{
u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
spin_lock(&arena->map_locks[idx].lock);
}
static void unlock_map(struct arena_info *arena, u32 premap)
__releases(&arena->map_locks[idx].lock)
{
u32 idx = (premap * MAP_ENT_SIZE / L1_CACHE_BYTES) % arena->nfree;
spin_unlock(&arena->map_locks[idx].lock);
}
static int btt_data_read(struct arena_info *arena, struct page *page,
unsigned int off, u32 lba, u32 len)
{
int ret;
u64 nsoff = to_namespace_offset(arena, lba);
void *mem = kmap_atomic(page);
ret = arena_read_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
kunmap_atomic(mem);
return ret;
}
static int btt_data_write(struct arena_info *arena, u32 lba,
struct page *page, unsigned int off, u32 len)
{
int ret;
u64 nsoff = to_namespace_offset(arena, lba);
void *mem = kmap_atomic(page);
ret = arena_write_bytes(arena, nsoff, mem + off, len, NVDIMM_IO_ATOMIC);
kunmap_atomic(mem);
return ret;
}
static void zero_fill_data(struct page *page, unsigned int off, u32 len)
{
void *mem = kmap_atomic(page);
memset(mem + off, 0, len);
kunmap_atomic(mem);
}
#ifdef CONFIG_BLK_DEV_INTEGRITY
static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
struct arena_info *arena, u32 postmap, int rw)
{
unsigned int len = btt_meta_size(btt);
u64 meta_nsoff;
int ret = 0;
if (bip == NULL)
return 0;
meta_nsoff = to_namespace_offset(arena, postmap) + btt->sector_size;
while (len) {
unsigned int cur_len;
struct bio_vec bv;
void *mem;
bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
/*
* The 'bv' obtained from bvec_iter_bvec has its .bv_len and
* .bv_offset already adjusted for iter->bi_bvec_done, and we
* can use those directly
*/
cur_len = min(len, bv.bv_len);
mem = kmap_atomic(bv.bv_page);
if (rw)
ret = arena_write_bytes(arena, meta_nsoff,
mem + bv.bv_offset, cur_len,
NVDIMM_IO_ATOMIC);
else
ret = arena_read_bytes(arena, meta_nsoff,
mem + bv.bv_offset, cur_len,
NVDIMM_IO_ATOMIC);
kunmap_atomic(mem);
if (ret)
return ret;
len -= cur_len;
meta_nsoff += cur_len;
if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len))
return -EIO;
}
return ret;
}
#else /* CONFIG_BLK_DEV_INTEGRITY */
static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
struct arena_info *arena, u32 postmap, int rw)
{
return 0;
}
#endif
static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip,
struct page *page, unsigned int off, sector_t sector,
unsigned int len)
{
int ret = 0;
int t_flag, e_flag;
struct arena_info *arena = NULL;
u32 lane = 0, premap, postmap;
while (len) {
u32 cur_len;
lane = nd_region_acquire_lane(btt->nd_region);
ret = lba_to_arena(btt, sector, &premap, &arena);
if (ret)
goto out_lane;
cur_len = min(btt->sector_size, len);
ret = btt_map_read(arena, premap, &postmap, &t_flag, &e_flag,
NVDIMM_IO_ATOMIC);
if (ret)
goto out_lane;
/*
* We loop to make sure that the post map LBA didn't change
* from under us between writing the RTT and doing the actual
* read.
*/
while (1) {
u32 new_map;
int new_t, new_e;
if (t_flag) {
zero_fill_data(page, off, cur_len);
goto out_lane;
}
if (e_flag) {
ret = -EIO;
goto out_lane;
}
arena->rtt[lane] = RTT_VALID | postmap;
/*
* Barrier to make sure this write is not reordered
* to do the verification map_read before the RTT store
*/
barrier();
ret = btt_map_read(arena, premap, &new_map, &new_t,
&new_e, NVDIMM_IO_ATOMIC);
if (ret)
goto out_rtt;
if ((postmap == new_map) && (t_flag == new_t) &&
(e_flag == new_e))
break;
postmap = new_map;
t_flag = new_t;
e_flag = new_e;
}
ret = btt_data_read(arena, page, off, postmap, cur_len);
if (ret) {
int rc;
/* Media error - set the e_flag */
rc = btt_map_write(arena, premap, postmap, 0, 1,
NVDIMM_IO_ATOMIC);
goto out_rtt;
}
if (bip) {
ret = btt_rw_integrity(btt, bip, arena, postmap, READ);
if (ret)
goto out_rtt;
}
arena->rtt[lane] = RTT_INVALID;
nd_region_release_lane(btt->nd_region, lane);
len -= cur_len;
off += cur_len;
sector += btt->sector_size >> SECTOR_SHIFT;
}
return 0;
out_rtt:
arena->rtt[lane] = RTT_INVALID;
out_lane:
nd_region_release_lane(btt->nd_region, lane);
return ret;
}
/*
* Normally, arena_{read,write}_bytes will take care of the initial offset
* adjustment, but in the case of btt_is_badblock, where we query is_bad_pmem,
* we need the final, raw namespace offset here
*/
static bool btt_is_badblock(struct btt *btt, struct arena_info *arena,
u32 postmap)
{
u64 nsoff = adjust_initial_offset(arena->nd_btt,
to_namespace_offset(arena, postmap));
sector_t phys_sector = nsoff >> 9;
return is_bad_pmem(btt->phys_bb, phys_sector, arena->internal_lbasize);
}
static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
sector_t sector, struct page *page, unsigned int off,
unsigned int len)
{
int ret = 0;
struct arena_info *arena = NULL;
u32 premap = 0, old_postmap, new_postmap, lane = 0, i;
struct log_entry log;
int sub;
while (len) {
u32 cur_len;
int e_flag;
retry:
lane = nd_region_acquire_lane(btt->nd_region);
ret = lba_to_arena(btt, sector, &premap, &arena);
if (ret)
goto out_lane;
cur_len = min(btt->sector_size, len);
if ((arena->flags & IB_FLAG_ERROR_MASK) != 0) {
ret = -EIO;
goto out_lane;
}
if (btt_is_badblock(btt, arena, arena->freelist[lane].block))
arena->freelist[lane].has_err = 1;
if (mutex_is_locked(&arena->err_lock)
|| arena->freelist[lane].has_err) {
nd_region_release_lane(btt->nd_region, lane);
ret = arena_clear_freelist_error(arena, lane);
if (ret)
return ret;
/* OK to acquire a different lane/free block */
goto retry;
}
new_postmap = arena->freelist[lane].block;
/* Wait if the new block is being read from */
for (i = 0; i < arena->nfree; i++)
while (arena->rtt[i] == (RTT_VALID | new_postmap))
cpu_relax();
if (new_postmap >= arena->internal_nlba) {
ret = -EIO;
goto out_lane;
}
ret = btt_data_write(arena, new_postmap, page, off, cur_len);
if (ret)
goto out_lane;
if (bip) {
ret = btt_rw_integrity(btt, bip, arena, new_postmap,
WRITE);
if (ret)
goto out_lane;
}
lock_map(arena, premap);
ret = btt_map_read(arena, premap, &old_postmap, NULL, &e_flag,
NVDIMM_IO_ATOMIC);
if (ret)
goto out_map;
if (old_postmap >= arena->internal_nlba) {
ret = -EIO;
goto out_map;
}
if (e_flag)
set_e_flag(old_postmap);
log.lba = cpu_to_le32(premap);
log.old_map = cpu_to_le32(old_postmap);
log.new_map = cpu_to_le32(new_postmap);
log.seq = cpu_to_le32(arena->freelist[lane].seq);
sub = arena->freelist[lane].sub;
ret = btt_flog_write(arena, lane, sub, &log);
if (ret)
goto out_map;
ret = btt_map_write(arena, premap, new_postmap, 0, 0,
NVDIMM_IO_ATOMIC);
if (ret)
goto out_map;
unlock_map(arena, premap);
nd_region_release_lane(btt->nd_region, lane);
if (e_flag) {
ret = arena_clear_freelist_error(arena, lane);
if (ret)
return ret;
}
len -= cur_len;
off += cur_len;
sector += btt->sector_size >> SECTOR_SHIFT;
}
return 0;
out_map:
unlock_map(arena, premap);
out_lane:
nd_region_release_lane(btt->nd_region, lane);
return ret;
}
static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
struct page *page, unsigned int len, unsigned int off,
unsigned int op, sector_t sector)
{
int ret;
if (!op_is_write(op)) {
ret = btt_read_pg(btt, bip, page, off, sector, len);
flush_dcache_page(page);
} else {
flush_dcache_page(page);
ret = btt_write_pg(btt, bip, sector, page, off, len);
}
return ret;
}
static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct btt *btt = q->queuedata;
struct bvec_iter iter;
unsigned long start;
struct bio_vec bvec;
int err = 0;
bool do_acct;
if (!bio_integrity_prep(bio))
return BLK_QC_T_NONE;
do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
unsigned int len = bvec.bv_len;
if (len > PAGE_SIZE || len < btt->sector_size ||
len % btt->sector_size) {
dev_err_ratelimited(&btt->nd_btt->dev,
"unaligned bio segment (len: %d)\n", len);
bio->bi_status = BLK_STS_IOERR;
break;
}
err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
bio_op(bio), iter.bi_sector);
if (err) {
dev_err(&btt->nd_btt->dev,
"io error in %s sector %lld, len %d,\n",
(op_is_write(bio_op(bio))) ? "WRITE" :
"READ",
(unsigned long long) iter.bi_sector, len);
bio->bi_status = errno_to_blk_status(err);
break;
}
}
if (do_acct)
nd_iostat_end(bio, start);
bio_endio(bio);
return BLK_QC_T_NONE;
}
static int btt_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, unsigned int op)
{
struct btt *btt = bdev->bd_disk->private_data;
int rc;
unsigned int len;
len = hpage_nr_pages(page) * PAGE_SIZE;
rc = btt_do_bvec(btt, NULL, page, len, 0, op, sector);
if (rc == 0)
page_endio(page, op_is_write(op), 0);
return rc;
}
static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo)
{
/* some standard values */
geo->heads = 1 << 6;
geo->sectors = 1 << 5;
geo->cylinders = get_capacity(bd->bd_disk) >> 11;
return 0;
}
static const struct block_device_operations btt_fops = {
.owner = THIS_MODULE,
.rw_page = btt_rw_page,
.getgeo = btt_getgeo,
.revalidate_disk = nvdimm_revalidate_disk,
};
static int btt_blk_init(struct btt *btt)
{
struct nd_btt *nd_btt = btt->nd_btt;
struct nd_namespace_common *ndns = nd_btt->ndns;
/* create a new disk and request queue for btt */
btt->btt_queue = blk_alloc_queue(GFP_KERNEL);
if (!btt->btt_queue)
return -ENOMEM;
btt->btt_disk = alloc_disk(0);
if (!btt->btt_disk) {
blk_cleanup_queue(btt->btt_queue);
return -ENOMEM;
}
nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name);
btt->btt_disk->first_minor = 0;
btt->btt_disk->fops = &btt_fops;
btt->btt_disk->private_data = btt;
btt->btt_disk->queue = btt->btt_queue;
btt->btt_disk->flags = GENHD_FL_EXT_DEVT;
btt->btt_disk->queue->backing_dev_info->capabilities |=
BDI_CAP_SYNCHRONOUS_IO;
blk_queue_make_request(btt->btt_queue, btt_make_request);
blk_queue_logical_block_size(btt->btt_queue, btt->sector_size);
blk_queue_max_hw_sectors(btt->btt_queue, UINT_MAX);
blk_queue_flag_set(QUEUE_FLAG_NONROT, btt->btt_queue);
btt->btt_queue->queuedata = btt;
if (btt_meta_size(btt)) {
int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
if (rc) {
del_gendisk(btt->btt_disk);
put_disk(btt->btt_disk);
blk_cleanup_queue(btt->btt_queue);
return rc;
}
}
set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
device_add_disk(&btt->nd_btt->dev, btt->btt_disk, NULL);
btt->nd_btt->size = btt->nlba * (u64)btt->sector_size;
revalidate_disk(btt->btt_disk);
return 0;
}
static void btt_blk_cleanup(struct btt *btt)
{
del_gendisk(btt->btt_disk);
put_disk(btt->btt_disk);
blk_cleanup_queue(btt->btt_queue);
}
/**
* btt_init - initialize a block translation table for the given device
* @nd_btt: device with BTT geometry and backing device info
* @rawsize: raw size in bytes of the backing device
* @lbasize: lba size of the backing device
* @uuid: A uuid for the backing device - this is stored on media
* @maxlane: maximum number of parallel requests the device can handle
*
* Initialize a Block Translation Table on a backing device to provide
* single sector power fail atomicity.
*
* Context:
* Might sleep.
*
* Returns:
* Pointer to a new struct btt on success, NULL on failure.
*/
static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
u32 lbasize, u8 *uuid, struct nd_region *nd_region)
{
int ret;
struct btt *btt;
struct nd_namespace_io *nsio;
struct device *dev = &nd_btt->dev;
btt = devm_kzalloc(dev, sizeof(struct btt), GFP_KERNEL);
if (!btt)
return NULL;
btt->nd_btt = nd_btt;
btt->rawsize = rawsize;
btt->lbasize = lbasize;
btt->sector_size = ((lbasize >= 4096) ? 4096 : 512);
INIT_LIST_HEAD(&btt->arena_list);
mutex_init(&btt->init_lock);
btt->nd_region = nd_region;
nsio = to_nd_namespace_io(&nd_btt->ndns->dev);
btt->phys_bb = &nsio->bb;
ret = discover_arenas(btt);
if (ret) {
dev_err(dev, "init: error in arena_discover: %d\n", ret);
return NULL;
}
if (btt->init_state != INIT_READY && nd_region->ro) {
dev_warn(dev, "%s is read-only, unable to init btt metadata\n",
dev_name(&nd_region->dev));
return NULL;
} else if (btt->init_state != INIT_READY) {
btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
dev_dbg(dev, "init: %d arenas for %llu rawsize\n",
btt->num_arenas, rawsize);
ret = create_arenas(btt);
if (ret) {
dev_info(dev, "init: create_arenas: %d\n", ret);
return NULL;
}
ret = btt_meta_init(btt);
if (ret) {
dev_err(dev, "init: error in meta_init: %d\n", ret);
return NULL;
}
}
ret = btt_blk_init(btt);
if (ret) {
dev_err(dev, "init: error in blk_init: %d\n", ret);
return NULL;
}
btt_debugfs_init(btt);
return btt;
}
/**
* btt_fini - de-initialize a BTT
* @btt: the BTT handle that was generated by btt_init
*
* De-initialize a Block Translation Table on device removal
*
* Context:
* Might sleep.
*/
static void btt_fini(struct btt *btt)
{
if (btt) {
btt_blk_cleanup(btt);
free_arenas(btt);
debugfs_remove_recursive(btt->debugfs_dir);
}
}
int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
{
struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
struct nd_region *nd_region;
struct btt_sb *btt_sb;
struct btt *btt;
size_t rawsize;
if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) {
dev_dbg(&nd_btt->dev, "incomplete btt configuration\n");
return -ENODEV;
}
btt_sb = devm_kzalloc(&nd_btt->dev, sizeof(*btt_sb), GFP_KERNEL);
if (!btt_sb)
return -ENOMEM;
/*
* If this returns < 0, that is ok as it just means there wasn't
* an existing BTT, and we're creating a new one. We still need to
* call this as we need the version dependent fields in nd_btt to be
* set correctly based on the holder class
*/
nd_btt_version(nd_btt, ndns, btt_sb);
rawsize = nvdimm_namespace_capacity(ndns) - nd_btt->initial_offset;
if (rawsize < ARENA_MIN_SIZE) {
dev_dbg(&nd_btt->dev, "%s must be at least %ld bytes\n",
dev_name(&ndns->dev),
ARENA_MIN_SIZE + nd_btt->initial_offset);
return -ENXIO;
}
nd_region = to_nd_region(nd_btt->dev.parent);
btt = btt_init(nd_btt, rawsize, nd_btt->lbasize, nd_btt->uuid,
nd_region);
if (!btt)
return -ENOMEM;
nd_btt->btt = btt;
return 0;
}
EXPORT_SYMBOL(nvdimm_namespace_attach_btt);
int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt)
{
struct btt *btt = nd_btt->btt;
btt_fini(btt);
nd_btt->btt = NULL;
return 0;
}
EXPORT_SYMBOL(nvdimm_namespace_detach_btt);
static int __init nd_btt_init(void)
{
int rc = 0;
debugfs_root = debugfs_create_dir("btt", NULL);
if (IS_ERR_OR_NULL(debugfs_root))
rc = -ENXIO;
return rc;
}
static void __exit nd_btt_exit(void)
{
debugfs_remove_recursive(debugfs_root);
}
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT);
MODULE_AUTHOR("Vishal Verma <vishal.l.verma@linux.intel.com>");
MODULE_LICENSE("GPL v2");
module_init(nd_btt_init);
module_exit(nd_btt_exit);