With the traditional page-based writes, blocks are allocated separately
for each page written to. With iomap writes, we can allocate a lot more
blocks at once, with a fraction of the allocation overhead for each
page.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/gfs2/aops.c | 7 +-
fs/gfs2/aops.h | 18 ++++++
fs/gfs2/bmap.c | 197 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--
fs/gfs2/file.c | 47 +++++++++++++-
4 files changed, 259 insertions(+), 10 deletions(-)
create mode 100644 fs/gfs2/aops.h
diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 42b56c06a97a..a4ce16b362bb 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -36,10 +36,11 @@
#include "super.h"
#include "util.h"
#include "glops.h"
+#include "aops.h"
-static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
- unsigned int from, unsigned int len)
+void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
+ unsigned int from, unsigned int len)
{
struct buffer_head *head = page_buffers(page);
unsigned int bsize = head->b_size;
@@ -773,7 +774,7 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping,
* adjust_fs_space - Adjusts the free space available due to gfs2_grow
* @inode: the rindex inode
*/
-static void adjust_fs_space(struct inode *inode)
+void adjust_fs_space(struct inode *inode)
{
struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
diff --git a/fs/gfs2/aops.h b/fs/gfs2/aops.h
new file mode 100644
index 000000000000..9a2fa61d8ca4
--- /dev/null
+++ b/fs/gfs2/aops.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2017 Red Hat, Inc. All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+#ifndef __AOPS_DOT_H__
+#define __AOPS_DOT_H__
+
+#include "incore.h"
+
+extern void adjust_fs_space(struct inode *inode);
+extern void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
+ unsigned int from, unsigned int len);
+
+#endif /* __AOPS_DOT_H__ */
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 0d6d81227477..382d5fb135c1 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -28,6 +28,7 @@
#include "trans.h"
#include "dir.h"
#include "util.h"
+#include "aops.h"
#include "trace_gfs2.h"
/* This doesn't need to be that large as max 64 bit pointers in a 4k
@@ -41,6 +42,8 @@ struct metapath {
int mp_aheight; /* actual height (lookup height) */
};
+static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length);
+
/**
* gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
* @ip: the inode
@@ -375,7 +378,7 @@ static int fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, int h)
return mp->mp_aheight - x - 1;
}
-static inline void release_metapath(struct metapath *mp)
+static void release_metapath(struct metapath *mp)
{
int i;
@@ -383,6 +386,7 @@ static inline void release_metapath(struct metapath *mp)
if (mp->mp_bh[i] == NULL)
break;
brelse(mp->mp_bh[i]);
+ mp->mp_bh[i] = NULL;
}
}
@@ -796,6 +800,172 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
goto out;
}
+static int gfs2_write_lock(struct inode *inode)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ int error;
+
+ gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
+ error = gfs2_glock_nq(&ip->i_gh);
+ if (error)
+ goto out_uninit;
+ if (&ip->i_inode == sdp->sd_rindex) {
+ struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
+
+ error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
+ GL_NOCACHE, &m_ip->i_gh);
+ if (error)
+ goto out_unlock;
+ }
+ return 0;
+
+out_unlock:
+ gfs2_glock_dq(&ip->i_gh);
+out_uninit:
+ gfs2_holder_uninit(&ip->i_gh);
+ return error;
+}
+
+static void gfs2_write_unlock(struct inode *inode)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+
+ if (&ip->i_inode == sdp->sd_rindex) {
+ struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
+
+ gfs2_glock_dq_uninit(&m_ip->i_gh);
+ }
+ gfs2_glock_dq_uninit(&ip->i_gh);
+}
+
+static int gfs2_iomap_write_begin(struct inode *inode, loff_t pos, loff_t length,
+ unsigned flags, struct iomap *iomap)
+{
+ struct metapath mp = { .mp_aheight = 1, };
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
+ int alloc_required;
+ int ret;
+
+ ret = gfs2_write_lock(inode);
+ if (ret)
+ return ret;
+
+ if (gfs2_is_stuffed(ip)) {
+ if (pos + length <= gfs2_max_stuffed_size(ip)) {
+ ret = -ENOTBLK;
+ goto out_unlock;
+ }
+ }
+
+ ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
+ if (ret)
+ goto out_release;
+ alloc_required = iomap->type != IOMAP_MAPPED;
+
+ if (alloc_required || gfs2_is_jdata(ip))
+ gfs2_write_calc_reserv(ip, iomap->length, &data_blocks, &ind_blocks);
+
+ if (alloc_required) {
+ struct gfs2_alloc_parms ap = { .target = data_blocks + ind_blocks };
+ ret = gfs2_quota_lock_check(ip, &ap);
+ if (ret)
+ goto out_release;
+
+ ret = gfs2_inplace_reserve(ip, &ap);
+ if (ret)
+ goto out_qunlock;
+ }
+
+ rblocks = RES_DINODE + ind_blocks;
+ if (gfs2_is_jdata(ip))
+ rblocks += data_blocks;
+ if (ind_blocks || data_blocks)
+ rblocks += RES_STATFS + RES_QUOTA;
+ if (inode == sdp->sd_rindex)
+ rblocks += 2 * RES_STATFS;
+ if (alloc_required)
+ rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
+
+ ret = gfs2_trans_begin(sdp, rblocks, iomap->length >> inode->i_blkbits);
+ if (ret)
+ goto out_trans_fail;
+
+ if (gfs2_is_stuffed(ip)) {
+ ret = gfs2_unstuff_dinode(ip, NULL);
+ if (ret)
+ goto out_trans_end;
+ release_metapath(&mp);
+ ret = gfs2_iomap_get(inode, iomap->offset, iomap->length,
+ flags, iomap, &mp);
+ if (ret)
+ goto out_trans_end;
+ }
+
+ if (iomap->type != IOMAP_MAPPED) {
+ ret = gfs2_iomap_alloc(inode, iomap, flags, &mp);
+ if (ret) {
+ gfs2_trans_end(sdp);
+ punch_hole(ip, iomap->offset, iomap->length);
+ goto out_trans_fail;
+ }
+ }
+ release_metapath(&mp);
+ return 0;
+
+out_trans_end:
+ gfs2_trans_end(sdp);
+out_trans_fail:
+ if (alloc_required) {
+ gfs2_inplace_release(ip);
+out_qunlock:
+ gfs2_quota_unlock(ip);
+ }
+out_release:
+ release_metapath(&mp);
+out_unlock:
+ gfs2_write_unlock(inode);
+ return ret;
+}
+
+static int gfs2_iomap_write_end(struct inode *inode, loff_t pos, loff_t length,
+ ssize_t written, struct iomap *iomap)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_trans *tr = current->journal_info;
+
+ BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
+
+ gfs2_ordered_add_inode(ip);
+
+ if (tr->tr_num_buf_new)
+ __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+
+ if (inode == sdp->sd_rindex) {
+ adjust_fs_space(inode);
+ sdp->sd_rindex_uptodate = 0;
+ }
+
+ if (length != written && (iomap->flags & IOMAP_F_NEW)) {
+ /* Deallocate blocks that were just allocated. */
+ pos += written;
+ length -= written;
+ truncate_pagecache_range(inode, pos, length);
+ punch_hole(ip, pos, length);
+ }
+
+ gfs2_trans_end(sdp);
+ gfs2_inplace_release(ip);
+ if (ip->i_qadata && ip->i_qadata->qa_qd_num)
+ gfs2_quota_unlock(ip);
+ gfs2_write_unlock(inode);
+ return 0;
+}
+
static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -805,10 +975,7 @@ static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
trace_gfs2_iomap_start(ip, pos, length, flags);
if (flags & IOMAP_WRITE) {
- ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
- if (!ret && iomap->type == IOMAP_HOLE)
- ret = gfs2_iomap_alloc(inode, iomap, flags, &mp);
- release_metapath(&mp);
+ ret = gfs2_iomap_write_begin(inode, pos, length, flags, iomap);
} else {
ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
release_metapath(&mp);
@@ -817,8 +984,28 @@ static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
return ret;
}
+static void gfs2_iomap_written(struct inode *inode, struct page *page,
+ unsigned int offset, unsigned int length,
+ unsigned int written)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+
+ if (gfs2_is_jdata(ip))
+ gfs2_page_add_databufs(ip, page, offset, length);
+}
+
+static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length,
+ ssize_t written, unsigned flags, struct iomap *iomap)
+{
+ if (flags & IOMAP_WRITE)
+ return gfs2_iomap_write_end(inode, pos, length, written, iomap);
+ return 0;
+}
+
const struct iomap_ops gfs2_iomap_ops = {
.iomap_begin = gfs2_iomap_begin,
+ .iomap_written = gfs2_iomap_written,
+ .iomap_end = gfs2_iomap_end,
};
/**
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index bd60dc682676..94d44e30d188 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -26,6 +26,7 @@
#include <linux/dlm.h>
#include <linux/dlm_plock.h>
#include <linux/delay.h>
+#include <linux/backing-dev.h>
#include "gfs2.h"
#include "incore.h"
@@ -686,6 +687,43 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
return ret ? ret : ret1;
}
+static ssize_t gfs2_file_buffered_write(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t ret;
+
+ inode_lock(inode);
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out;
+
+ ret = file_remove_privs(file);
+ if (ret)
+ goto out;
+
+ ret = file_update_time(file);
+ if (ret)
+ goto out;
+
+ /* We can write back this queue in page reclaim */
+ current->backing_dev_info = inode_to_bdi(inode);
+
+ ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
+
+ current->backing_dev_info = NULL;
+
+out:
+ inode_unlock(inode);
+ if (likely(ret > 0)) {
+ iocb->ki_pos += ret;
+
+ /* Handle various SYNC-type writes */
+ ret = generic_write_sync(iocb, ret);
+ }
+ return ret;
+}
+
/**
* gfs2_file_write_iter - Perform a write to a file
* @iocb: The io context
@@ -704,7 +742,7 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct gfs2_inode *ip = GFS2_I(file_inode(file));
- int ret;
+ ssize_t ret;
ret = gfs2_rsqa_alloc(ip);
if (ret)
@@ -721,7 +759,12 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
gfs2_glock_dq_uninit(&gh);
}
- return generic_file_write_iter(iocb, from);
+ if (iocb->ki_flags & IOCB_DIRECT)
+ return generic_file_write_iter(iocb, from);
+ ret = gfs2_file_buffered_write(iocb, from);
+ if (ret == -ENOTBLK)
+ ret = generic_file_write_iter(iocb, from);
+ return ret;
}
static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
--
2.14.3
