Commit 4667a0ec authored by Steven Whitehouse's avatar Steven Whitehouse

GFS2: Make writeback more responsive to system conditions

This patch adds writeback_control to writing back the AIL
list. This means that we can then take advantage of the
information we get in ->write_inode() in order to set off
some pre-emptive writeback.

In addition, the AIL code is cleaned up a bit to make it
a bit simpler to understand.

There is still more which can usefully be done in this area,
but this is a good start at least.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent f42ab085
......@@ -139,7 +139,7 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb,
struct gfs2_sbd *sdp = sb->s_fs_info;
struct inode *inode;
inode = gfs2_ilookup(sb, inum->no_addr);
inode = gfs2_ilookup(sb, inum->no_addr, 0);
if (inode) {
if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
iput(inode);
......
......@@ -649,7 +649,7 @@ static void delete_work_func(struct work_struct *work)
/* Note: Unsafe to dereference ip as we don't hold right refs/locks */
if (ip)
inode = gfs2_ilookup(sdp->sd_vfs, no_addr);
inode = gfs2_ilookup(sdp->sd_vfs, no_addr, 1);
else
inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
if (inode && !IS_ERR(inode)) {
......
......@@ -20,7 +20,6 @@
#define DIO_WAIT 0x00000010
#define DIO_METADATA 0x00000020
#define DIO_ALL 0x00000100
struct gfs2_log_operations;
struct gfs2_log_element;
......@@ -377,8 +376,6 @@ struct gfs2_ail {
unsigned int ai_first;
struct list_head ai_ail1_list;
struct list_head ai_ail2_list;
u64 ai_sync_gen;
};
struct gfs2_journal_extent {
......@@ -657,7 +654,6 @@ struct gfs2_sbd {
spinlock_t sd_ail_lock;
struct list_head sd_ail1_list;
struct list_head sd_ail2_list;
u64 sd_ail_sync_gen;
/* Replay stuff */
......
......@@ -74,14 +74,14 @@ static int iget_set(struct inode *inode, void *opaque)
return 0;
}
struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr)
struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr, int non_block)
{
unsigned long hash = (unsigned long)no_addr;
struct gfs2_skip_data data;
data.no_addr = no_addr;
data.skipped = 0;
data.non_block = 0;
data.non_block = non_block;
return ilookup5(sb, hash, iget_test, &data);
}
......
......@@ -102,7 +102,7 @@ extern struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned type,
extern struct inode *gfs2_lookup_by_inum(struct gfs2_sbd *sdp, u64 no_addr,
u64 *no_formal_ino,
unsigned int blktype);
extern struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr);
extern struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr, int nonblock);
extern int gfs2_inode_refresh(struct gfs2_inode *ip);
......
......@@ -18,6 +18,7 @@
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/bio.h>
#include <linux/writeback.h>
#include "gfs2.h"
#include "incore.h"
......@@ -83,50 +84,90 @@ void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
/**
* gfs2_ail1_start_one - Start I/O on a part of the AIL
* @sdp: the filesystem
* @tr: the part of the AIL
* @wbc: The writeback control structure
* @ai: The ail structure
*
*/
static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
static void gfs2_ail1_start_one(struct gfs2_sbd *sdp,
struct writeback_control *wbc,
struct gfs2_ail *ai)
__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 retry;
do {
retry = 0;
restart:
list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {
bh = bd->bd_bh;
list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
bd_ail_st_list) {
bh = bd->bd_bh;
gfs2_assert(sdp, bd->bd_ail == ai);
gfs2_assert(sdp, bd->bd_ail == ai);
if (!buffer_busy(bh)) {
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
continue;
}
if (!buffer_dirty(bh))
continue;
if (gl == bd->bd_gl)
continue;
gl = bd->bd_gl;
list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
mapping = bh->b_page->mapping;
spin_unlock(&sdp->sd_ail_lock);
generic_writepages(mapping, wbc);
spin_lock(&sdp->sd_ail_lock);
if (wbc->nr_to_write <= 0)
break;
goto restart;
}
}
if (!buffer_busy(bh)) {
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
continue;
}
if (!buffer_dirty(bh))
continue;
if (gl == bd->bd_gl)
continue;
gl = bd->bd_gl;
list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
/**
* 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
*/
spin_unlock(&sdp->sd_ail_lock);
filemap_fdatawrite(gfs2_glock2aspace(gl));
spin_lock(&sdp->sd_ail_lock);
void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
{
struct list_head *head = &sdp->sd_ail1_list;
struct gfs2_ail *ai;
retry = 1;
spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_reverse(ai, head, ai_list) {
if (wbc->nr_to_write <= 0)
break;
}
} while (retry);
gfs2_ail1_start_one(sdp, wbc, ai); /* This may drop ail lock */
}
spin_unlock(&sdp->sd_ail_lock);
}
/**
* 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);
}
/**
......@@ -136,7 +177,7 @@ __acquires(&sdp->sd_ail_lock)
*
*/
static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
{
struct gfs2_bufdata *bd, *s;
struct buffer_head *bh;
......@@ -144,71 +185,37 @@ static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int fl
list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
bd_ail_st_list) {
bh = bd->bd_bh;
gfs2_assert(sdp, bd->bd_ail == ai);
if (buffer_busy(bh)) {
if (flags & DIO_ALL)
continue;
else
break;
}
if (buffer_busy(bh))
continue;
if (!buffer_uptodate(bh))
gfs2_io_error_bh(sdp, bh);
list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
}
return list_empty(&ai->ai_ail1_list);
}
static void gfs2_ail1_start(struct gfs2_sbd *sdp)
{
struct list_head *head;
u64 sync_gen;
struct gfs2_ail *ai;
int done = 0;
spin_lock(&sdp->sd_ail_lock);
head = &sdp->sd_ail1_list;
if (list_empty(head)) {
spin_unlock(&sdp->sd_ail_lock);
return;
}
sync_gen = sdp->sd_ail_sync_gen++;
while(!done) {
done = 1;
list_for_each_entry_reverse(ai, head, ai_list) {
if (ai->ai_sync_gen >= sync_gen)
continue;
ai->ai_sync_gen = sync_gen;
gfs2_ail1_start_one(sdp, ai); /* This may drop ail lock */
done = 0;
break;
}
}
spin_unlock(&sdp->sd_ail_lock);
}
/**
* gfs2_ail1_empty - Try to empty the ail1 lists
* @sdp: The superblock
*
* Tries to empty the ail1 lists, starting with the oldest first
*/
static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
{
struct gfs2_ail *ai, *s;
int ret;
spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
if (gfs2_ail1_empty_one(sdp, ai, flags))
gfs2_ail1_empty_one(sdp, ai);
if (list_empty(&ai->ai_ail1_list))
list_move(&ai->ai_list, &sdp->sd_ail2_list);
else if (!(flags & DIO_ALL))
else
break;
}
ret = list_empty(&sdp->sd_ail1_list);
spin_unlock(&sdp->sd_ail_lock);
return ret;
......@@ -569,7 +576,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
set_buffer_uptodate(bh);
clear_buffer_dirty(bh);
gfs2_ail1_empty(sdp, 0);
gfs2_ail1_empty(sdp);
tail = current_tail(sdp);
lh = (struct gfs2_log_header *)bh->b_data;
......@@ -864,7 +871,7 @@ void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
gfs2_log_flush(sdp, NULL);
for (;;) {
gfs2_ail1_start(sdp);
if (gfs2_ail1_empty(sdp, DIO_ALL))
if (gfs2_ail1_empty(sdp))
break;
msleep(10);
}
......@@ -900,17 +907,15 @@ int gfs2_logd(void *data)
preflush = atomic_read(&sdp->sd_log_pinned);
if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
gfs2_ail1_empty(sdp, DIO_ALL);
gfs2_ail1_empty(sdp);
gfs2_log_flush(sdp, NULL);
gfs2_ail1_empty(sdp, DIO_ALL);
}
if (gfs2_ail_flush_reqd(sdp)) {
gfs2_ail1_start(sdp);
io_schedule();
gfs2_ail1_empty(sdp, 0);
gfs2_ail1_empty(sdp);
gfs2_log_flush(sdp, NULL);
gfs2_ail1_empty(sdp, DIO_ALL);
}
wake_up(&sdp->sd_log_waitq);
......
......@@ -12,6 +12,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/writeback.h>
#include "incore.h"
/**
......@@ -59,6 +60,7 @@ extern struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
extern void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl);
extern void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
extern void gfs2_remove_from_ail(struct gfs2_bufdata *bd);
extern void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc);
extern void gfs2_log_shutdown(struct gfs2_sbd *sdp);
extern void gfs2_meta_syncfs(struct gfs2_sbd *sdp);
......
......@@ -23,6 +23,7 @@
#include <linux/time.h>
#include <linux/wait.h>
#include <linux/writeback.h>
#include <linux/backing-dev.h>
#include "gfs2.h"
#include "incore.h"
......@@ -714,6 +715,7 @@ static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
struct backing_dev_info *bdi = metamapping->backing_dev_info;
struct gfs2_holder gh;
struct buffer_head *bh;
struct timespec atime;
......@@ -747,6 +749,8 @@ do_flush:
if (wbc->sync_mode == WB_SYNC_ALL)
gfs2_log_flush(GFS2_SB(inode), ip->i_gl);
filemap_fdatawrite(metamapping);
if (bdi->dirty_exceeded)
gfs2_ail1_flush(sdp, wbc);
if (!ret && (wbc->sync_mode == WB_SYNC_ALL))
ret = filemap_fdatawait(metamapping);
if (ret)
......@@ -1366,7 +1370,8 @@ static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
if (error)
goto out_rindex_relse;
error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA, 1);
error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
sdp->sd_jdesc->jd_blocks);
if (error)
goto out_rg_gunlock;
......
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