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linuxdebug/fs/gfs2/log.c

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null pointer error
2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/crc32c.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/writeback.h>
#include <linux/list_sort.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "util.h"
#include "dir.h"
#include "trace_gfs2.h"
#include "trans.h"
static void gfs2_log_shutdown(struct gfs2_sbd *sdp);
/**
* gfs2_struct2blk - compute stuff
* @sdp: the filesystem
* @nstruct: the number of structures
*
* Compute the number of log descriptor blocks needed to hold a certain number
* of structures of a certain size.
*
* Returns: the number of blocks needed (minimum is always 1)
*/
unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct)
{
unsigned int blks;
unsigned int first, second;
/* The initial struct gfs2_log_descriptor block */
blks = 1;
first = sdp->sd_ldptrs;
if (nstruct > first) {
/* Subsequent struct gfs2_meta_header blocks */
second = sdp->sd_inptrs;
blks += DIV_ROUND_UP(nstruct - first, second);
}
return blks;
}
/**
* gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
* @bd: The gfs2_bufdata to remove
*
* The ail lock _must_ be held when calling this function
*
*/
void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
{
bd->bd_tr = NULL;
list_del_init(&bd->bd_ail_st_list);
list_del_init(&bd->bd_ail_gl_list);
atomic_dec(&bd->bd_gl->gl_ail_count);
brelse(bd->bd_bh);
}
static int __gfs2_writepage(struct page *page, struct writeback_control *wbc,
void *data)
{
struct address_space *mapping = data;
int ret = mapping->a_ops->writepage(page, wbc);
mapping_set_error(mapping, ret);
return ret;
}
/**
* gfs2_ail1_start_one - Start I/O on a transaction
* @sdp: The superblock
* @wbc: The writeback control structure
* @tr: The transaction to start I/O on
* @plug: The block plug currently active
*/
static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
struct writeback_control *wbc,
struct gfs2_trans *tr, struct blk_plug *plug)
__releases(&sdp->sd_ail_lock)
__acquires(&sdp->sd_ail_lock)
{
struct gfs2_glock *gl = NULL;
struct address_space *mapping;
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
int ret = 0;
list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
bh = bd->bd_bh;
gfs2_assert(sdp, bd->bd_tr == tr);
if (!buffer_busy(bh)) {
if (buffer_uptodate(bh)) {
list_move(&bd->bd_ail_st_list,
&tr->tr_ail2_list);
continue;
}
if (!cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
gfs2_io_error_bh(sdp, bh);
gfs2_withdraw_delayed(sdp);
}
}
if (gfs2_withdrawn(sdp)) {
gfs2_remove_from_ail(bd);
continue;
}
if (!buffer_dirty(bh))
continue;
if (gl == bd->bd_gl)
continue;
gl = bd->bd_gl;
list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
mapping = bh->b_page->mapping;
if (!mapping)
continue;
spin_unlock(&sdp->sd_ail_lock);
ret = write_cache_pages(mapping, wbc, __gfs2_writepage, mapping);
if (need_resched()) {
blk_finish_plug(plug);
cond_resched();
blk_start_plug(plug);
}
spin_lock(&sdp->sd_ail_lock);
if (ret == -ENODATA) /* if a jdata write into a new hole */
ret = 0; /* ignore it */
if (ret || wbc->nr_to_write <= 0)
break;
return -EBUSY;
}
return ret;
}
static void dump_ail_list(struct gfs2_sbd *sdp)
{
struct gfs2_trans *tr;
struct gfs2_bufdata *bd;
struct buffer_head *bh;
list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
list_for_each_entry_reverse(bd, &tr->tr_ail1_list,
bd_ail_st_list) {
bh = bd->bd_bh;
fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd,
(unsigned long long)bd->bd_blkno, bh);
if (!bh) {
fs_err(sdp, "\n");
continue;
}
fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d "
"map:%d new:%d ar:%d aw:%d delay:%d "
"io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n",
(unsigned long long)bh->b_blocknr,
buffer_uptodate(bh), buffer_dirty(bh),
buffer_locked(bh), buffer_req(bh),
buffer_mapped(bh), buffer_new(bh),
buffer_async_read(bh), buffer_async_write(bh),
buffer_delay(bh), buffer_write_io_error(bh),
buffer_unwritten(bh),
buffer_defer_completion(bh),
buffer_pinned(bh), buffer_escaped(bh));
}
}
}
/**
* gfs2_ail1_flush - start writeback of some ail1 entries
* @sdp: The super block
* @wbc: The writeback control structure
*
* Writes back some ail1 entries, according to the limits in the
* writeback control structure
*/
void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
{
struct list_head *head = &sdp->sd_ail1_list;
struct gfs2_trans *tr;
struct blk_plug plug;
int ret;
unsigned long flush_start = jiffies;
trace_gfs2_ail_flush(sdp, wbc, 1);
blk_start_plug(&plug);
spin_lock(&sdp->sd_ail_lock);
restart:
ret = 0;
if (time_after(jiffies, flush_start + (HZ * 600))) {
fs_err(sdp, "Error: In %s for ten minutes! t=%d\n",
__func__, current->journal_info ? 1 : 0);
dump_ail_list(sdp);
goto out;
}
list_for_each_entry_reverse(tr, head, tr_list) {
if (wbc->nr_to_write <= 0)
break;
ret = gfs2_ail1_start_one(sdp, wbc, tr, &plug);
if (ret) {
if (ret == -EBUSY)
goto restart;
break;
}
}
out:
spin_unlock(&sdp->sd_ail_lock);
blk_finish_plug(&plug);
if (ret) {
gfs2_lm(sdp, "gfs2_ail1_start_one returned: %d\n", ret);
gfs2_withdraw(sdp);
}
trace_gfs2_ail_flush(sdp, wbc, 0);
}
/**
* gfs2_ail1_start - start writeback of all ail1 entries
* @sdp: The superblock
*/
static void gfs2_ail1_start(struct gfs2_sbd *sdp)
{
struct writeback_control wbc = {
.sync_mode = WB_SYNC_NONE,
.nr_to_write = LONG_MAX,
.range_start = 0,
.range_end = LLONG_MAX,
};
return gfs2_ail1_flush(sdp, &wbc);
}
static void gfs2_log_update_flush_tail(struct gfs2_sbd *sdp)
{
unsigned int new_flush_tail = sdp->sd_log_head;
struct gfs2_trans *tr;
if (!list_empty(&sdp->sd_ail1_list)) {
tr = list_last_entry(&sdp->sd_ail1_list,
struct gfs2_trans, tr_list);
new_flush_tail = tr->tr_first;
}
sdp->sd_log_flush_tail = new_flush_tail;
}
static void gfs2_log_update_head(struct gfs2_sbd *sdp)
{
unsigned int new_head = sdp->sd_log_flush_head;
if (sdp->sd_log_flush_tail == sdp->sd_log_head)
sdp->sd_log_flush_tail = new_head;
sdp->sd_log_head = new_head;
}
/*
* gfs2_ail_empty_tr - empty one of the ail lists of a transaction
*/
static void gfs2_ail_empty_tr(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
struct list_head *head)
{
struct gfs2_bufdata *bd;
while (!list_empty(head)) {
bd = list_first_entry(head, struct gfs2_bufdata,
bd_ail_st_list);
gfs2_assert(sdp, bd->bd_tr == tr);
gfs2_remove_from_ail(bd);
}
}
/**
* gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
* @sdp: the filesystem
* @tr: the transaction
* @max_revokes: If nonzero, issue revokes for the bd items for written buffers
*
* returns: the transaction's count of remaining active items
*/
static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
int *max_revokes)
{
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
int active_count = 0;
list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
bd_ail_st_list) {
bh = bd->bd_bh;
gfs2_assert(sdp, bd->bd_tr == tr);
/*
* If another process flagged an io error, e.g. writing to the
* journal, error all other bhs and move them off the ail1 to
* prevent a tight loop when unmount tries to flush ail1,
* regardless of whether they're still busy. If no outside
* errors were found and the buffer is busy, move to the next.
* If the ail buffer is not busy and caught an error, flag it
* for others.
*/
if (!sdp->sd_log_error && buffer_busy(bh)) {
active_count++;
continue;
}
if (!buffer_uptodate(bh) &&
!cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
gfs2_io_error_bh(sdp, bh);
gfs2_withdraw_delayed(sdp);
}
/*
* If we have space for revokes and the bd is no longer on any
* buf list, we can just add a revoke for it immediately and
* avoid having to put it on the ail2 list, where it would need
* to be revoked later.
*/
if (*max_revokes && list_empty(&bd->bd_list)) {
gfs2_add_revoke(sdp, bd);
(*max_revokes)--;
continue;
}
list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
}
return active_count;
}
/**
* gfs2_ail1_empty - Try to empty the ail1 lists
* @sdp: The superblock
* @max_revokes: If non-zero, add revokes where appropriate
*
* Tries to empty the ail1 lists, starting with the oldest first
*/
static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes)
{
struct gfs2_trans *tr, *s;
int oldest_tr = 1;
int ret;
spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
if (!gfs2_ail1_empty_one(sdp, tr, &max_revokes) && oldest_tr)
list_move(&tr->tr_list, &sdp->sd_ail2_list);
else
oldest_tr = 0;
}
gfs2_log_update_flush_tail(sdp);
ret = list_empty(&sdp->sd_ail1_list);
spin_unlock(&sdp->sd_ail_lock);
if (test_bit(SDF_WITHDRAWING, &sdp->sd_flags)) {
gfs2_lm(sdp, "fatal: I/O error(s)\n");
gfs2_withdraw(sdp);
}
return ret;
}
static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
{
struct gfs2_trans *tr;
struct gfs2_bufdata *bd;
struct buffer_head *bh;
spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
bh = bd->bd_bh;
if (!buffer_locked(bh))
continue;
get_bh(bh);
spin_unlock(&sdp->sd_ail_lock);
wait_on_buffer(bh);
brelse(bh);
return;
}
}
spin_unlock(&sdp->sd_ail_lock);
}
static void __ail2_empty(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
list_del(&tr->tr_list);
gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
gfs2_trans_free(sdp, tr);
}
static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
{
struct list_head *ail2_list = &sdp->sd_ail2_list;
unsigned int old_tail = sdp->sd_log_tail;
struct gfs2_trans *tr, *safe;
spin_lock(&sdp->sd_ail_lock);
if (old_tail <= new_tail) {
list_for_each_entry_safe(tr, safe, ail2_list, tr_list) {
if (old_tail <= tr->tr_first && tr->tr_first < new_tail)
__ail2_empty(sdp, tr);
}
} else {
list_for_each_entry_safe(tr, safe, ail2_list, tr_list) {
if (old_tail <= tr->tr_first || tr->tr_first < new_tail)
__ail2_empty(sdp, tr);
}
}
spin_unlock(&sdp->sd_ail_lock);
}
/**
* gfs2_log_is_empty - Check if the log is empty
* @sdp: The GFS2 superblock
*/
bool gfs2_log_is_empty(struct gfs2_sbd *sdp) {
return atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks;
}
static bool __gfs2_log_try_reserve_revokes(struct gfs2_sbd *sdp, unsigned int revokes)
{
unsigned int available;
available = atomic_read(&sdp->sd_log_revokes_available);
while (available >= revokes) {
if (atomic_try_cmpxchg(&sdp->sd_log_revokes_available,
&available, available - revokes))
return true;
}
return false;
}
/**
* gfs2_log_release_revokes - Release a given number of revokes
* @sdp: The GFS2 superblock
* @revokes: The number of revokes to release
*
* sdp->sd_log_flush_lock must be held.
*/
void gfs2_log_release_revokes(struct gfs2_sbd *sdp, unsigned int revokes)
{
if (revokes)
atomic_add(revokes, &sdp->sd_log_revokes_available);
}
/**
* gfs2_log_release - Release a given number of log blocks
* @sdp: The GFS2 superblock
* @blks: The number of blocks
*
*/
void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
{
atomic_add(blks, &sdp->sd_log_blks_free);
trace_gfs2_log_blocks(sdp, blks);
gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
sdp->sd_jdesc->jd_blocks);
if (atomic_read(&sdp->sd_log_blks_needed))
wake_up(&sdp->sd_log_waitq);
}
/**
* __gfs2_log_try_reserve - Try to make a log reservation
* @sdp: The GFS2 superblock
* @blks: The number of blocks to reserve
* @taboo_blks: The number of blocks to leave free
*
* Try to do the same as __gfs2_log_reserve(), but fail if no more log
* space is immediately available.
*/
static bool __gfs2_log_try_reserve(struct gfs2_sbd *sdp, unsigned int blks,
unsigned int taboo_blks)
{
unsigned wanted = blks + taboo_blks;
unsigned int free_blocks;
free_blocks = atomic_read(&sdp->sd_log_blks_free);
while (free_blocks >= wanted) {
if (atomic_try_cmpxchg(&sdp->sd_log_blks_free, &free_blocks,
free_blocks - blks)) {
trace_gfs2_log_blocks(sdp, -blks);
return true;
}
}
return false;
}
/**
* __gfs2_log_reserve - Make a log reservation
* @sdp: The GFS2 superblock
* @blks: The number of blocks to reserve
* @taboo_blks: The number of blocks to leave free
*
* @taboo_blks is set to 0 for logd, and to GFS2_LOG_FLUSH_MIN_BLOCKS
* for all other processes. This ensures that when the log is almost full,
* logd will still be able to call gfs2_log_flush one more time without
* blocking, which will advance the tail and make some more log space
* available.
*
* We no longer flush the log here, instead we wake up logd to do that
* for us. To avoid the thundering herd and to ensure that we deal fairly
* with queued waiters, we use an exclusive wait. This means that when we
* get woken with enough journal space to get our reservation, we need to
* wake the next waiter on the list.
*/
static void __gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks,
unsigned int taboo_blks)
{
unsigned wanted = blks + taboo_blks;
unsigned int free_blocks;
atomic_add(blks, &sdp->sd_log_blks_needed);
for (;;) {
if (current != sdp->sd_logd_process)
wake_up(&sdp->sd_logd_waitq);
io_wait_event(sdp->sd_log_waitq,
(free_blocks = atomic_read(&sdp->sd_log_blks_free),
free_blocks >= wanted));
do {
if (atomic_try_cmpxchg(&sdp->sd_log_blks_free,
&free_blocks,
free_blocks - blks))
goto reserved;
} while (free_blocks >= wanted);
}
reserved:
trace_gfs2_log_blocks(sdp, -blks);
if (atomic_sub_return(blks, &sdp->sd_log_blks_needed))
wake_up(&sdp->sd_log_waitq);
}
/**
* gfs2_log_try_reserve - Try to make a log reservation
* @sdp: The GFS2 superblock
* @tr: The transaction
* @extra_revokes: The number of additional revokes reserved (output)
*
* This is similar to gfs2_log_reserve, but sdp->sd_log_flush_lock must be
* held for correct revoke accounting.
*/
bool gfs2_log_try_reserve(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
unsigned int *extra_revokes)
{
unsigned int blks = tr->tr_reserved;
unsigned int revokes = tr->tr_revokes;
unsigned int revoke_blks = 0;
*extra_revokes = 0;
if (revokes && !__gfs2_log_try_reserve_revokes(sdp, revokes)) {
revoke_blks = DIV_ROUND_UP(revokes, sdp->sd_inptrs);
*extra_revokes = revoke_blks * sdp->sd_inptrs - revokes;
blks += revoke_blks;
}
if (!blks)
return true;
if (__gfs2_log_try_reserve(sdp, blks, GFS2_LOG_FLUSH_MIN_BLOCKS))
return true;
if (!revoke_blks)
gfs2_log_release_revokes(sdp, revokes);
return false;
}
/**
* gfs2_log_reserve - Make a log reservation
* @sdp: The GFS2 superblock
* @tr: The transaction
* @extra_revokes: The number of additional revokes reserved (output)
*
* sdp->sd_log_flush_lock must not be held.
*/
void gfs2_log_reserve(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
unsigned int *extra_revokes)
{
unsigned int blks = tr->tr_reserved;
unsigned int revokes = tr->tr_revokes;
unsigned int revoke_blks;
*extra_revokes = 0;
if (revokes) {
revoke_blks = DIV_ROUND_UP(revokes, sdp->sd_inptrs);
*extra_revokes = revoke_blks * sdp->sd_inptrs - revokes;
blks += revoke_blks;
}
__gfs2_log_reserve(sdp, blks, GFS2_LOG_FLUSH_MIN_BLOCKS);
}
/**
* log_distance - Compute distance between two journal blocks
* @sdp: The GFS2 superblock
* @newer: The most recent journal block of the pair
* @older: The older journal block of the pair
*
* Compute the distance (in the journal direction) between two
* blocks in the journal
*
* Returns: the distance in blocks
*/
static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
unsigned int older)
{
int dist;
dist = newer - older;
if (dist < 0)
dist += sdp->sd_jdesc->jd_blocks;
return dist;
}
/**
* calc_reserved - Calculate the number of blocks to keep reserved
* @sdp: The GFS2 superblock
*
* This is complex. We need to reserve room for all our currently used
* metadata blocks (e.g. normal file I/O rewriting file time stamps) and
* all our journaled data blocks for journaled files (e.g. files in the
* meta_fs like rindex, or files for which chattr +j was done.)
* If we don't reserve enough space, corruption will follow.
*
* We can have metadata blocks and jdata blocks in the same journal. Each
* type gets its own log descriptor, for which we need to reserve a block.
* In fact, each type has the potential for needing more than one log descriptor
* in cases where we have more blocks than will fit in a log descriptor.
* Metadata journal entries take up half the space of journaled buffer entries.
*
* Also, we need to reserve blocks for revoke journal entries and one for an
* overall header for the lot.
*
* Returns: the number of blocks reserved
*/
static unsigned int calc_reserved(struct gfs2_sbd *sdp)
{
unsigned int reserved = GFS2_LOG_FLUSH_MIN_BLOCKS;
unsigned int blocks;
struct gfs2_trans *tr = sdp->sd_log_tr;
if (tr) {
blocks = tr->tr_num_buf_new - tr->tr_num_buf_rm;
reserved += blocks + DIV_ROUND_UP(blocks, buf_limit(sdp));
blocks = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
reserved += blocks + DIV_ROUND_UP(blocks, databuf_limit(sdp));
}
return reserved;
}
static void log_pull_tail(struct gfs2_sbd *sdp)
{
unsigned int new_tail = sdp->sd_log_flush_tail;
unsigned int dist;
if (new_tail == sdp->sd_log_tail)
return;
dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
ail2_empty(sdp, new_tail);
gfs2_log_release(sdp, dist);
sdp->sd_log_tail = new_tail;
}
void log_flush_wait(struct gfs2_sbd *sdp)
{
DEFINE_WAIT(wait);
if (atomic_read(&sdp->sd_log_in_flight)) {
do {
prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (atomic_read(&sdp->sd_log_in_flight))
io_schedule();
} while(atomic_read(&sdp->sd_log_in_flight));
finish_wait(&sdp->sd_log_flush_wait, &wait);
}
}
static int ip_cmp(void *priv, const struct list_head *a, const struct list_head *b)
{
struct gfs2_inode *ipa, *ipb;
ipa = list_entry(a, struct gfs2_inode, i_ordered);
ipb = list_entry(b, struct gfs2_inode, i_ordered);
if (ipa->i_no_addr < ipb->i_no_addr)
return -1;
if (ipa->i_no_addr > ipb->i_no_addr)
return 1;
return 0;
}
static void __ordered_del_inode(struct gfs2_inode *ip)
{
if (!list_empty(&ip->i_ordered))
list_del_init(&ip->i_ordered);
}
static void gfs2_ordered_write(struct gfs2_sbd *sdp)
{
struct gfs2_inode *ip;
LIST_HEAD(written);
spin_lock(&sdp->sd_ordered_lock);
list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp);
while (!list_empty(&sdp->sd_log_ordered)) {
ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
if (ip->i_inode.i_mapping->nrpages == 0) {
__ordered_del_inode(ip);
continue;
}
list_move(&ip->i_ordered, &written);
spin_unlock(&sdp->sd_ordered_lock);
filemap_fdatawrite(ip->i_inode.i_mapping);
spin_lock(&sdp->sd_ordered_lock);
}
list_splice(&written, &sdp->sd_log_ordered);
spin_unlock(&sdp->sd_ordered_lock);
}
static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
{
struct gfs2_inode *ip;
spin_lock(&sdp->sd_ordered_lock);
while (!list_empty(&sdp->sd_log_ordered)) {
ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
__ordered_del_inode(ip);
if (ip->i_inode.i_mapping->nrpages == 0)
continue;
spin_unlock(&sdp->sd_ordered_lock);
filemap_fdatawait(ip->i_inode.i_mapping);
spin_lock(&sdp->sd_ordered_lock);
}
spin_unlock(&sdp->sd_ordered_lock);
}
void gfs2_ordered_del_inode(struct gfs2_inode *ip)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
spin_lock(&sdp->sd_ordered_lock);
__ordered_del_inode(ip);
spin_unlock(&sdp->sd_ordered_lock);
}
void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
{
struct buffer_head *bh = bd->bd_bh;
struct gfs2_glock *gl = bd->bd_gl;
sdp->sd_log_num_revoke++;
if (atomic_inc_return(&gl->gl_revokes) == 1)
gfs2_glock_hold(gl);
bh->b_private = NULL;
bd->bd_blkno = bh->b_blocknr;
gfs2_remove_from_ail(bd); /* drops ref on bh */
bd->bd_bh = NULL;
set_bit(GLF_LFLUSH, &gl->gl_flags);
list_add(&bd->bd_list, &sdp->sd_log_revokes);
}
void gfs2_glock_remove_revoke(struct gfs2_glock *gl)
{
if (atomic_dec_return(&gl->gl_revokes) == 0) {
clear_bit(GLF_LFLUSH, &gl->gl_flags);
gfs2_glock_queue_put(gl);
}
}
/**
* gfs2_flush_revokes - Add as many revokes to the system transaction as we can
* @sdp: The GFS2 superblock
*
* Our usual strategy is to defer writing revokes as much as we can in the hope
* that we'll eventually overwrite the journal, which will make those revokes
* go away. This changes when we flush the log: at that point, there will
* likely be some left-over space in the last revoke block of that transaction.
* We can fill that space with additional revokes for blocks that have already
* been written back. This will basically come at no cost now, and will save
* us from having to keep track of those blocks on the AIL2 list later.
*/
void gfs2_flush_revokes(struct gfs2_sbd *sdp)
{
/* number of revokes we still have room for */
unsigned int max_revokes = atomic_read(&sdp->sd_log_revokes_available);
gfs2_log_lock(sdp);
gfs2_ail1_empty(sdp, max_revokes);
gfs2_log_unlock(sdp);
}
/**
* gfs2_write_log_header - Write a journal log header buffer at lblock
* @sdp: The GFS2 superblock
* @jd: journal descriptor of the journal to which we are writing
* @seq: sequence number
* @tail: tail of the log
* @lblock: value for lh_blkno (block number relative to start of journal)
* @flags: log header flags GFS2_LOG_HEAD_*
* @op_flags: flags to pass to the bio
*
* Returns: the initialized log buffer descriptor
*/
void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
u64 seq, u32 tail, u32 lblock, u32 flags,
blk_opf_t op_flags)
{
struct gfs2_log_header *lh;
u32 hash, crc;
struct page *page;
struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
struct timespec64 tv;
struct super_block *sb = sdp->sd_vfs;
u64 dblock;
if (gfs2_withdrawn(sdp))
return;
page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
lh = page_address(page);
clear_page(lh);
lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
lh->lh_header.__pad0 = cpu_to_be64(0);
lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
lh->lh_sequence = cpu_to_be64(seq);
lh->lh_flags = cpu_to_be32(flags);
lh->lh_tail = cpu_to_be32(tail);
lh->lh_blkno = cpu_to_be32(lblock);
hash = ~crc32(~0, lh, LH_V1_SIZE);
lh->lh_hash = cpu_to_be32(hash);
ktime_get_coarse_real_ts64(&tv);
lh->lh_nsec = cpu_to_be32(tv.tv_nsec);
lh->lh_sec = cpu_to_be64(tv.tv_sec);
if (!list_empty(&jd->extent_list))
dblock = gfs2_log_bmap(jd, lblock);
else {
unsigned int extlen;
int ret;
extlen = 1;
ret = gfs2_get_extent(jd->jd_inode, lblock, &dblock, &extlen);
if (gfs2_assert_withdraw(sdp, ret == 0))
return;
}
lh->lh_addr = cpu_to_be64(dblock);
lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr);
/* We may only write local statfs, quota, etc., when writing to our
own journal. The values are left 0 when recovering a journal
different from our own. */
if (!(flags & GFS2_LOG_HEAD_RECOVERY)) {
lh->lh_statfs_addr =
cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
lh->lh_quota_addr =
cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
spin_lock(&sdp->sd_statfs_spin);
lh->lh_local_total = cpu_to_be64(l_sc->sc_total);
lh->lh_local_free = cpu_to_be64(l_sc->sc_free);
lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes);
spin_unlock(&sdp->sd_statfs_spin);
}
BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE);
crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
sb->s_blocksize - LH_V1_SIZE - 4);
lh->lh_crc = cpu_to_be32(crc);
gfs2_log_write(sdp, jd, page, sb->s_blocksize, 0, dblock);
gfs2_log_submit_bio(&jd->jd_log_bio, REQ_OP_WRITE | op_flags);
}
/**
* log_write_header - Get and initialize a journal header buffer
* @sdp: The GFS2 superblock
* @flags: The log header flags, including log header origin
*
* Returns: the initialized log buffer descriptor
*/
static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
{
blk_opf_t op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC;
enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
gfs2_ordered_wait(sdp);
log_flush_wait(sdp);
op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
}
sdp->sd_log_idle = (sdp->sd_log_flush_tail == sdp->sd_log_flush_head);
gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++,
sdp->sd_log_flush_tail, sdp->sd_log_flush_head,
flags, op_flags);
gfs2_log_incr_head(sdp);
log_flush_wait(sdp);
log_pull_tail(sdp);
gfs2_log_update_head(sdp);
}
/**
* gfs2_ail_drain - drain the ail lists after a withdraw
* @sdp: Pointer to GFS2 superblock
*/
void gfs2_ail_drain(struct gfs2_sbd *sdp)
{
struct gfs2_trans *tr;
spin_lock(&sdp->sd_ail_lock);
/*
* For transactions on the sd_ail1_list we need to drain both the
* ail1 and ail2 lists. That's because function gfs2_ail1_start_one
* (temporarily) moves items from its tr_ail1 list to tr_ail2 list
* before revokes are sent for that block. Items on the sd_ail2_list
* should have already gotten beyond that point, so no need.
*/
while (!list_empty(&sdp->sd_ail1_list)) {
tr = list_first_entry(&sdp->sd_ail1_list, struct gfs2_trans,
tr_list);
gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail1_list);
gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
list_del(&tr->tr_list);
gfs2_trans_free(sdp, tr);
}
while (!list_empty(&sdp->sd_ail2_list)) {
tr = list_first_entry(&sdp->sd_ail2_list, struct gfs2_trans,
tr_list);
gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
list_del(&tr->tr_list);
gfs2_trans_free(sdp, tr);
}
gfs2_drain_revokes(sdp);
spin_unlock(&sdp->sd_ail_lock);
}
/**
* empty_ail1_list - try to start IO and empty the ail1 list
* @sdp: Pointer to GFS2 superblock
*/
static void empty_ail1_list(struct gfs2_sbd *sdp)
{
unsigned long start = jiffies;
for (;;) {
if (time_after(jiffies, start + (HZ * 600))) {
fs_err(sdp, "Error: In %s for 10 minutes! t=%d\n",
__func__, current->journal_info ? 1 : 0);
dump_ail_list(sdp);
return;
}
gfs2_ail1_start(sdp);
gfs2_ail1_wait(sdp);
if (gfs2_ail1_empty(sdp, 0))
return;
}
}
/**
* trans_drain - drain the buf and databuf queue for a failed transaction
* @tr: the transaction to drain
*
* When this is called, we're taking an error exit for a log write that failed
* but since we bypassed the after_commit functions, we need to remove the
* items from the buf and databuf queue.
*/
static void trans_drain(struct gfs2_trans *tr)
{
struct gfs2_bufdata *bd;
struct list_head *head;
if (!tr)
return;
head = &tr->tr_buf;
while (!list_empty(head)) {
bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
list_del_init(&bd->bd_list);
if (!list_empty(&bd->bd_ail_st_list))
gfs2_remove_from_ail(bd);
kmem_cache_free(gfs2_bufdata_cachep, bd);
}
head = &tr->tr_databuf;
while (!list_empty(head)) {
bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
list_del_init(&bd->bd_list);
if (!list_empty(&bd->bd_ail_st_list))
gfs2_remove_from_ail(bd);
kmem_cache_free(gfs2_bufdata_cachep, bd);
}
}
/**
* gfs2_log_flush - flush incore transaction(s)
* @sdp: The filesystem
* @gl: The glock structure to flush. If NULL, flush the whole incore log
* @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags
*
*/
void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
{
struct gfs2_trans *tr = NULL;
unsigned int reserved_blocks = 0, used_blocks = 0;
enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
unsigned int first_log_head;
unsigned int reserved_revokes = 0;
down_write(&sdp->sd_log_flush_lock);
trace_gfs2_log_flush(sdp, 1, flags);
repeat:
/*
* Do this check while holding the log_flush_lock to prevent new
* buffers from being added to the ail via gfs2_pin()
*/
if (gfs2_withdrawn(sdp) || !test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
goto out;
/* Log might have been flushed while we waited for the flush lock */
if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags))
goto out;
first_log_head = sdp->sd_log_head;
sdp->sd_log_flush_head = first_log_head;
tr = sdp->sd_log_tr;
if (tr || sdp->sd_log_num_revoke) {
if (reserved_blocks)
gfs2_log_release(sdp, reserved_blocks);
reserved_blocks = sdp->sd_log_blks_reserved;
reserved_revokes = sdp->sd_log_num_revoke;
if (tr) {
sdp->sd_log_tr = NULL;
tr->tr_first = first_log_head;
if (unlikely (state == SFS_FROZEN)) {
if (gfs2_assert_withdraw_delayed(sdp,
!tr->tr_num_buf_new && !tr->tr_num_databuf_new))
goto out_withdraw;
}
}
} else if (!reserved_blocks) {
unsigned int taboo_blocks = GFS2_LOG_FLUSH_MIN_BLOCKS;
reserved_blocks = GFS2_LOG_FLUSH_MIN_BLOCKS;
if (current == sdp->sd_logd_process)
taboo_blocks = 0;
if (!__gfs2_log_try_reserve(sdp, reserved_blocks, taboo_blocks)) {
up_write(&sdp->sd_log_flush_lock);
__gfs2_log_reserve(sdp, reserved_blocks, taboo_blocks);
down_write(&sdp->sd_log_flush_lock);
goto repeat;
}
BUG_ON(sdp->sd_log_num_revoke);
}
if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN)
clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
if (unlikely(state == SFS_FROZEN))
if (gfs2_assert_withdraw_delayed(sdp, !reserved_revokes))
goto out_withdraw;
gfs2_ordered_write(sdp);
if (gfs2_withdrawn(sdp))
goto out_withdraw;
lops_before_commit(sdp, tr);
if (gfs2_withdrawn(sdp))
goto out_withdraw;
gfs2_log_submit_bio(&sdp->sd_jdesc->jd_log_bio, REQ_OP_WRITE);
if (gfs2_withdrawn(sdp))
goto out_withdraw;
if (sdp->sd_log_head != sdp->sd_log_flush_head) {
log_write_header(sdp, flags);
} else if (sdp->sd_log_tail != sdp->sd_log_flush_tail && !sdp->sd_log_idle) {
log_write_header(sdp, flags);
}
if (gfs2_withdrawn(sdp))
goto out_withdraw;
lops_after_commit(sdp, tr);
gfs2_log_lock(sdp);
sdp->sd_log_blks_reserved = 0;
spin_lock(&sdp->sd_ail_lock);
if (tr && !list_empty(&tr->tr_ail1_list)) {
list_add(&tr->tr_list, &sdp->sd_ail1_list);
tr = NULL;
}
spin_unlock(&sdp->sd_ail_lock);
gfs2_log_unlock(sdp);
if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) {
if (!sdp->sd_log_idle) {
empty_ail1_list(sdp);
if (gfs2_withdrawn(sdp))
goto out_withdraw;
log_write_header(sdp, flags);
}
if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
GFS2_LOG_HEAD_FLUSH_FREEZE))
gfs2_log_shutdown(sdp);
if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE)
atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
}
out_end:
used_blocks = log_distance(sdp, sdp->sd_log_flush_head, first_log_head);
reserved_revokes += atomic_read(&sdp->sd_log_revokes_available);
atomic_set(&sdp->sd_log_revokes_available, sdp->sd_ldptrs);
gfs2_assert_withdraw(sdp, reserved_revokes % sdp->sd_inptrs == sdp->sd_ldptrs);
if (reserved_revokes > sdp->sd_ldptrs)
reserved_blocks += (reserved_revokes - sdp->sd_ldptrs) / sdp->sd_inptrs;
out:
if (used_blocks != reserved_blocks) {
gfs2_assert_withdraw_delayed(sdp, used_blocks < reserved_blocks);
gfs2_log_release(sdp, reserved_blocks - used_blocks);
}
up_write(&sdp->sd_log_flush_lock);
gfs2_trans_free(sdp, tr);
if (gfs2_withdrawing(sdp))
gfs2_withdraw(sdp);
trace_gfs2_log_flush(sdp, 0, flags);
return;
out_withdraw:
trans_drain(tr);
/**
* If the tr_list is empty, we're withdrawing during a log
* flush that targets a transaction, but the transaction was
* never queued onto any of the ail lists. Here we add it to
* ail1 just so that ail_drain() will find and free it.
*/
spin_lock(&sdp->sd_ail_lock);
if (tr && list_empty(&tr->tr_list))
list_add(&tr->tr_list, &sdp->sd_ail1_list);
spin_unlock(&sdp->sd_ail_lock);
tr = NULL;
goto out_end;
}
/**
* gfs2_merge_trans - Merge a new transaction into a cached transaction
* @sdp: the filesystem
* @new: New transaction to be merged
*/
static void gfs2_merge_trans(struct gfs2_sbd *sdp, struct gfs2_trans *new)
{
struct gfs2_trans *old = sdp->sd_log_tr;
WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
old->tr_num_buf_new += new->tr_num_buf_new;
old->tr_num_databuf_new += new->tr_num_databuf_new;
old->tr_num_buf_rm += new->tr_num_buf_rm;
old->tr_num_databuf_rm += new->tr_num_databuf_rm;
old->tr_revokes += new->tr_revokes;
old->tr_num_revoke += new->tr_num_revoke;
list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
list_splice_tail_init(&new->tr_buf, &old->tr_buf);
spin_lock(&sdp->sd_ail_lock);
list_splice_tail_init(&new->tr_ail1_list, &old->tr_ail1_list);
list_splice_tail_init(&new->tr_ail2_list, &old->tr_ail2_list);
spin_unlock(&sdp->sd_ail_lock);
}
static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
unsigned int reserved;
unsigned int unused;
unsigned int maxres;
gfs2_log_lock(sdp);
if (sdp->sd_log_tr) {
gfs2_merge_trans(sdp, tr);
} else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
gfs2_assert_withdraw(sdp, !test_bit(TR_ONSTACK, &tr->tr_flags));
sdp->sd_log_tr = tr;
set_bit(TR_ATTACHED, &tr->tr_flags);
}
reserved = calc_reserved(sdp);
maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
gfs2_assert_withdraw(sdp, maxres >= reserved);
unused = maxres - reserved;
if (unused)
gfs2_log_release(sdp, unused);
sdp->sd_log_blks_reserved = reserved;
gfs2_log_unlock(sdp);
}
/**
* gfs2_log_commit - Commit a transaction to the log
* @sdp: the filesystem
* @tr: the transaction
*
* We wake up gfs2_logd if the number of pinned blocks exceed thresh1
* or the total number of used blocks (pinned blocks plus AIL blocks)
* is greater than thresh2.
*
* At mount time thresh1 is 2/5ths of journal size, thresh2 is 4/5ths of
* journal size.
*
* Returns: errno
*/
void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
log_refund(sdp, tr);
if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
atomic_read(&sdp->sd_log_thresh2)))
wake_up(&sdp->sd_logd_waitq);
}
/**
* gfs2_log_shutdown - write a shutdown header into a journal
* @sdp: the filesystem
*
*/
static void gfs2_log_shutdown(struct gfs2_sbd *sdp)
{
gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN);
log_pull_tail(sdp);
gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
}
static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
{
return (atomic_read(&sdp->sd_log_pinned) +
atomic_read(&sdp->sd_log_blks_needed) >=
atomic_read(&sdp->sd_log_thresh1));
}
static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
{
unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
atomic_read(&sdp->sd_log_thresh2);
}
/**
* gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
* @data: Pointer to GFS2 superblock
*
* Also, periodically check to make sure that we're using the most recent
* journal index.
*/
int gfs2_logd(void *data)
{
struct gfs2_sbd *sdp = data;
unsigned long t = 1;
while (!kthread_should_stop()) {
if (gfs2_withdrawn(sdp)) {
msleep_interruptible(HZ);
continue;
}
/* Check for errors writing to the journal */
if (sdp->sd_log_error) {
gfs2_lm(sdp,
"GFS2: fsid=%s: error %d: "
"withdrawing the file system to "
"prevent further damage.\n",
sdp->sd_fsname, sdp->sd_log_error);
gfs2_withdraw(sdp);
continue;
}
if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
gfs2_ail1_empty(sdp, 0);
gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
GFS2_LFC_LOGD_JFLUSH_REQD);
}
if (test_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags) ||
gfs2_ail_flush_reqd(sdp)) {
clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
gfs2_ail1_start(sdp);
gfs2_ail1_wait(sdp);
gfs2_ail1_empty(sdp, 0);
gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
GFS2_LFC_LOGD_AIL_FLUSH_REQD);
}
t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
try_to_freeze();
t = wait_event_interruptible_timeout(sdp->sd_logd_waitq,
test_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags) ||
gfs2_ail_flush_reqd(sdp) ||
gfs2_jrnl_flush_reqd(sdp) ||
kthread_should_stop(),
t);
}
return 0;
}