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linux/fs/ocfs2/aops.c

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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* Copyright (C) 2002, 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that 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.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <asm/byteorder.h>
#include <linux/swap.h>
#include <linux/pipe_fs_i.h>
#define MLOG_MASK_PREFIX ML_FILE_IO
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "aops.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "suballoc.h"
#include "super.h"
#include "symlink.h"
#include "buffer_head_io.h"
static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int err = -EIO;
int status;
struct ocfs2_dinode *fe = NULL;
struct buffer_head *bh = NULL;
struct buffer_head *buffer_cache_bh = NULL;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
void *kaddr;
mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
(unsigned long long)iblock, bh_result, create);
BUG_ON(ocfs2_inode_is_fast_symlink(inode));
if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
(unsigned long long)iblock);
goto bail;
}
status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
OCFS2_I(inode)->ip_blkno,
&bh, OCFS2_BH_CACHED, inode);
if (status < 0) {
mlog_errno(status);
goto bail;
}
fe = (struct ocfs2_dinode *) bh->b_data;
if (!OCFS2_IS_VALID_DINODE(fe)) {
mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
(unsigned long long)le64_to_cpu(fe->i_blkno), 7,
fe->i_signature);
goto bail;
}
if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
le32_to_cpu(fe->i_clusters))) {
mlog(ML_ERROR, "block offset is outside the allocated size: "
"%llu\n", (unsigned long long)iblock);
goto bail;
}
/* We don't use the page cache to create symlink data, so if
* need be, copy it over from the buffer cache. */
if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
iblock;
buffer_cache_bh = sb_getblk(osb->sb, blkno);
if (!buffer_cache_bh) {
mlog(ML_ERROR, "couldn't getblock for symlink!\n");
goto bail;
}
/* we haven't locked out transactions, so a commit
* could've happened. Since we've got a reference on
* the bh, even if it commits while we're doing the
* copy, the data is still good. */
if (buffer_jbd(buffer_cache_bh)
&& ocfs2_inode_is_new(inode)) {
kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
if (!kaddr) {
mlog(ML_ERROR, "couldn't kmap!\n");
goto bail;
}
memcpy(kaddr + (bh_result->b_size * iblock),
buffer_cache_bh->b_data,
bh_result->b_size);
kunmap_atomic(kaddr, KM_USER0);
set_buffer_uptodate(bh_result);
}
brelse(buffer_cache_bh);
}
map_bh(bh_result, inode->i_sb,
le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
err = 0;
bail:
if (bh)
brelse(bh);
mlog_exit(err);
return err;
}
static int ocfs2_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int err = 0;
unsigned int ext_flags;
u64 p_blkno, past_eof;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
(unsigned long long)iblock, bh_result, create);
if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
inode, inode->i_ino);
if (S_ISLNK(inode->i_mode)) {
/* this always does I/O for some reason. */
err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
goto bail;
}
err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL,
&ext_flags);
if (err) {
mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
"%llu, NULL)\n", err, inode, (unsigned long long)iblock,
(unsigned long long)p_blkno);
goto bail;
}
/*
* ocfs2 never allocates in this function - the only time we
* need to use BH_New is when we're extending i_size on a file
* system which doesn't support holes, in which case BH_New
* allows block_prepare_write() to zero.
*/
mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb),
"ino %lu, iblock %llu\n", inode->i_ino,
(unsigned long long)iblock);
/* Treat the unwritten extent as a hole for zeroing purposes. */
if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
map_bh(bh_result, inode->i_sb, p_blkno);
if (!ocfs2_sparse_alloc(osb)) {
if (p_blkno == 0) {
err = -EIO;
mlog(ML_ERROR,
"iblock = %llu p_blkno = %llu blkno=(%llu)\n",
(unsigned long long)iblock,
(unsigned long long)p_blkno,
(unsigned long long)OCFS2_I(inode)->ip_blkno);
mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
dump_stack();
}
past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
(unsigned long long)past_eof);
if (create && (iblock >= past_eof))
set_buffer_new(bh_result);
}
bail:
if (err < 0)
err = -EIO;
mlog_exit(err);
return err;
}
static int ocfs2_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
int ret, unlock = 1;
mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page);
if (ret != 0) {
if (ret == AOP_TRUNCATED_PAGE)
unlock = 0;
mlog_errno(ret);
goto out;
}
if (down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem) == 0) {
ret = AOP_TRUNCATED_PAGE;
goto out_meta_unlock;
}
/*
* i_size might have just been updated as we grabed the meta lock. We
* might now be discovering a truncate that hit on another node.
* block_read_full_page->get_block freaks out if it is asked to read
* beyond the end of a file, so we check here. Callers
* (generic_file_read, fault->nopage) are clever enough to check i_size
* and notice that the page they just read isn't needed.
*
* XXX sys_readahead() seems to get that wrong?
*/
if (start >= i_size_read(inode)) {
zero_user_page(page, 0, PAGE_SIZE, KM_USER0);
SetPageUptodate(page);
ret = 0;
goto out_alloc;
}
ret = ocfs2_data_lock_with_page(inode, 0, page);
if (ret != 0) {
if (ret == AOP_TRUNCATED_PAGE)
unlock = 0;
mlog_errno(ret);
goto out_alloc;
}
ret = block_read_full_page(page, ocfs2_get_block);
unlock = 0;
ocfs2_data_unlock(inode, 0);
out_alloc:
up_read(&OCFS2_I(inode)->ip_alloc_sem);
out_meta_unlock:
ocfs2_meta_unlock(inode, 0);
out:
if (unlock)
unlock_page(page);
mlog_exit(ret);
return ret;
}
/* Note: Because we don't support holes, our allocation has
* already happened (allocation writes zeros to the file data)
* so we don't have to worry about ordered writes in
* ocfs2_writepage.
*
* ->writepage is called during the process of invalidating the page cache
* during blocked lock processing. It can't block on any cluster locks
* to during block mapping. It's relying on the fact that the block
* mapping can't have disappeared under the dirty pages that it is
* being asked to write back.
*/
static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
{
int ret;
mlog_entry("(0x%p)\n", page);
ret = block_write_full_page(page, ocfs2_get_block, wbc);
mlog_exit(ret);
return ret;
}
/*
* This is called from ocfs2_write_zero_page() which has handled it's
* own cluster locking and has ensured allocation exists for those
* blocks to be written.
*/
int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
unsigned from, unsigned to)
{
int ret;
down_read(&OCFS2_I(inode)->ip_alloc_sem);
ret = block_prepare_write(page, from, to, ocfs2_get_block);
up_read(&OCFS2_I(inode)->ip_alloc_sem);
return ret;
}
/* Taken from ext3. We don't necessarily need the full blown
* functionality yet, but IMHO it's better to cut and paste the whole
* thing so we can avoid introducing our own bugs (and easily pick up
* their fixes when they happen) --Mark */
int walk_page_buffers( handle_t *handle,
struct buffer_head *head,
unsigned from,
unsigned to,
int *partial,
int (*fn)( handle_t *handle,
struct buffer_head *bh))
{
struct buffer_head *bh;
unsigned block_start, block_end;
unsigned blocksize = head->b_size;
int err, ret = 0;
struct buffer_head *next;
for ( bh = head, block_start = 0;
ret == 0 && (bh != head || !block_start);
block_start = block_end, bh = next)
{
next = bh->b_this_page;
block_end = block_start + blocksize;
if (block_end <= from || block_start >= to) {
if (partial && !buffer_uptodate(bh))
*partial = 1;
continue;
}
err = (*fn)(handle, bh);
if (!ret)
ret = err;
}
return ret;
}
handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
struct page *page,
unsigned from,
unsigned to)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
handle_t *handle = NULL;
int ret = 0;
handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
if (!handle) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
if (ocfs2_should_order_data(inode)) {
ret = walk_page_buffers(handle,
page_buffers(page),
from, to, NULL,
ocfs2_journal_dirty_data);
if (ret < 0)
mlog_errno(ret);
}
out:
if (ret) {
if (handle)
ocfs2_commit_trans(osb, handle);
handle = ERR_PTR(ret);
}
return handle;
}
static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
{
sector_t status;
u64 p_blkno = 0;
int err = 0;
struct inode *inode = mapping->host;
mlog_entry("(block = %llu)\n", (unsigned long long)block);
/* We don't need to lock journal system files, since they aren't
* accessed concurrently from multiple nodes.
*/
if (!INODE_JOURNAL(inode)) {
err = ocfs2_meta_lock(inode, NULL, 0);
if (err) {
if (err != -ENOENT)
mlog_errno(err);
goto bail;
}
down_read(&OCFS2_I(inode)->ip_alloc_sem);
}
err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL);
if (!INODE_JOURNAL(inode)) {
up_read(&OCFS2_I(inode)->ip_alloc_sem);
ocfs2_meta_unlock(inode, 0);
}
if (err) {
mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
(unsigned long long)block);
mlog_errno(err);
goto bail;
}
bail:
status = err ? 0 : p_blkno;
mlog_exit((int)status);
return status;
}
/*
* TODO: Make this into a generic get_blocks function.
*
* From do_direct_io in direct-io.c:
* "So what we do is to permit the ->get_blocks function to populate
* bh.b_size with the size of IO which is permitted at this offset and
* this i_blkbits."
*
* This function is called directly from get_more_blocks in direct-io.c.
*
* called like this: dio->get_blocks(dio->inode, fs_startblk,
* fs_count, map_bh, dio->rw == WRITE);
*/
static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int ret;
u64 p_blkno, inode_blocks, contig_blocks;
unsigned int ext_flags;
unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
/* This function won't even be called if the request isn't all
* nicely aligned and of the right size, so there's no need
* for us to check any of that. */
inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
/*
* Any write past EOF is not allowed because we'd be extending.
*/
if (create && (iblock + max_blocks) > inode_blocks) {
ret = -EIO;
goto bail;
}
/* This figures out the size of the next contiguous block, and
* our logical offset */
ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
&contig_blocks, &ext_flags);
if (ret) {
mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
(unsigned long long)iblock);
ret = -EIO;
goto bail;
}
if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) {
ocfs2_error(inode->i_sb,
"Inode %llu has a hole at block %llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)iblock);
ret = -EROFS;
goto bail;
}
/*
* get_more_blocks() expects us to describe a hole by clearing
* the mapped bit on bh_result().
*
* Consider an unwritten extent as a hole.
*/
if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
map_bh(bh_result, inode->i_sb, p_blkno);
else {
/*
* ocfs2_prepare_inode_for_write() should have caught
* the case where we'd be filling a hole and triggered
* a buffered write instead.
*/
if (create) {
ret = -EIO;
mlog_errno(ret);
goto bail;
}
clear_buffer_mapped(bh_result);
}
/* make sure we don't map more than max_blocks blocks here as
that's all the kernel will handle at this point. */
if (max_blocks < contig_blocks)
contig_blocks = max_blocks;
bh_result->b_size = contig_blocks << blocksize_bits;
bail:
return ret;
}
/*
* ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
* particularly interested in the aio/dio case. Like the core uses
* i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
* truncation on another.
*/
static void ocfs2_dio_end_io(struct kiocb *iocb,
loff_t offset,
ssize_t bytes,
void *private)
{
struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
int level;
/* this io's submitter should not have unlocked this before we could */
BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
ocfs2_iocb_clear_rw_locked(iocb);
level = ocfs2_iocb_rw_locked_level(iocb);
if (!level)
up_read(&inode->i_alloc_sem);
ocfs2_rw_unlock(inode, level);
}
/*
* ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
* from ext3. PageChecked() bits have been removed as OCFS2 does not
* do journalled data.
*/
static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
{
journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
journal_invalidatepage(journal, page, offset);
}
static int ocfs2_releasepage(struct page *page, gfp_t wait)
{
journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
if (!page_has_buffers(page))
return 0;
return journal_try_to_free_buffers(journal, page, wait);
}
static ssize_t ocfs2_direct_IO(int rw,
struct kiocb *iocb,
const struct iovec *iov,
loff_t offset,
unsigned long nr_segs)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
int ret;
mlog_entry_void();
if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
/*
* We get PR data locks even for O_DIRECT. This
* allows concurrent O_DIRECT I/O but doesn't let
* O_DIRECT with extending and buffered zeroing writes
* race. If they did race then the buffered zeroing
* could be written back after the O_DIRECT I/O. It's
* one thing to tell people not to mix buffered and
* O_DIRECT writes, but expecting them to understand
* that file extension is also an implicit buffered
* write is too much. By getting the PR we force
* writeback of the buffered zeroing before
* proceeding.
*/
ret = ocfs2_data_lock(inode, 0);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
ocfs2_data_unlock(inode, 0);
}
ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
inode->i_sb->s_bdev, iov, offset,
nr_segs,
ocfs2_direct_IO_get_blocks,
ocfs2_dio_end_io);
out:
mlog_exit(ret);
return ret;
}
static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
u32 cpos,
unsigned int *start,
unsigned int *end)
{
unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
unsigned int cpp;
cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
cluster_start = cpos % cpp;
cluster_start = cluster_start << osb->s_clustersize_bits;
cluster_end = cluster_start + osb->s_clustersize;
}
BUG_ON(cluster_start > PAGE_SIZE);
BUG_ON(cluster_end > PAGE_SIZE);
if (start)
*start = cluster_start;
if (end)
*end = cluster_end;
}
/*
* 'from' and 'to' are the region in the page to avoid zeroing.
*
* If pagesize > clustersize, this function will avoid zeroing outside
* of the cluster boundary.
*
* from == to == 0 is code for "zero the entire cluster region"
*/
static void ocfs2_clear_page_regions(struct page *page,
struct ocfs2_super *osb, u32 cpos,
unsigned from, unsigned to)
{
void *kaddr;
unsigned int cluster_start, cluster_end;
ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
kaddr = kmap_atomic(page, KM_USER0);
if (from || to) {
if (from > cluster_start)
memset(kaddr + cluster_start, 0, from - cluster_start);
if (to < cluster_end)
memset(kaddr + to, 0, cluster_end - to);
} else {
memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
}
kunmap_atomic(kaddr, KM_USER0);
}
/*
* Some of this taken from block_prepare_write(). We already have our
* mapping by now though, and the entire write will be allocating or
* it won't, so not much need to use BH_New.
*
* This will also skip zeroing, which is handled externally.
*/
int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
struct inode *inode, unsigned int from,
unsigned int to, int new)
{
int ret = 0;
struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
unsigned int block_end, block_start;
unsigned int bsize = 1 << inode->i_blkbits;
if (!page_has_buffers(page))
create_empty_buffers(page, bsize, 0);
head = page_buffers(page);
for (bh = head, block_start = 0; bh != head || !block_start;
bh = bh->b_this_page, block_start += bsize) {
block_end = block_start + bsize;
/*
* Ignore blocks outside of our i/o range -
* they may belong to unallocated clusters.
*/
if (block_start >= to || block_end <= from) {
if (PageUptodate(page))
set_buffer_uptodate(bh);
continue;
}
/*
* For an allocating write with cluster size >= page
* size, we always write the entire page.
*/
if (buffer_new(bh))
clear_buffer_new(bh);
if (!buffer_mapped(bh)) {
map_bh(bh, inode->i_sb, *p_blkno);
unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
}
if (PageUptodate(page)) {
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
(block_start < from || block_end > to)) {
ll_rw_block(READ, 1, &bh);
*wait_bh++=bh;
}
*p_blkno = *p_blkno + 1;
}
/*
* If we issued read requests - let them complete.
*/
while(wait_bh > wait) {
wait_on_buffer(*--wait_bh);
if (!buffer_uptodate(*wait_bh))
ret = -EIO;
}
if (ret == 0 || !new)
return ret;
/*
* If we get -EIO above, zero out any newly allocated blocks
* to avoid exposing stale data.
*/
bh = head;
block_start = 0;
do {
void *kaddr;
block_end = block_start + bsize;
if (block_end <= from)
goto next_bh;
if (block_start >= to)
break;
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr+block_start, 0, bh->b_size);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
next_bh:
block_start = block_end;
bh = bh->b_this_page;
} while (bh != head);
return ret;
}
/*
* This will copy user data from the buffer page in the splice
* context.
*
* For now, we ignore SPLICE_F_MOVE as that would require some extra
* communication out all the way to ocfs2_write().
*/
int ocfs2_map_and_write_splice_data(struct inode *inode,
struct ocfs2_write_ctxt *wc, u64 *p_blkno,
unsigned int *ret_from, unsigned int *ret_to)
{
int ret;
unsigned int to, from, cluster_start, cluster_end;
char *src, *dst;
struct ocfs2_splice_write_priv *sp = wc->w_private;
struct pipe_buffer *buf = sp->s_buf;
unsigned long bytes, src_from;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start,
&cluster_end);
from = sp->s_offset;
src_from = sp->s_buf_offset;
bytes = wc->w_count;
if (wc->w_large_pages) {
/*
* For cluster size < page size, we have to
* calculate pos within the cluster and obey
* the rightmost boundary.
*/
bytes = min(bytes, (unsigned long)(osb->s_clustersize
- (wc->w_pos & (osb->s_clustersize - 1))));
}
to = from + bytes;
BUG_ON(from > PAGE_CACHE_SIZE);
BUG_ON(to > PAGE_CACHE_SIZE);
BUG_ON(from < cluster_start);
BUG_ON(to > cluster_end);
if (wc->w_this_page_new)
ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
cluster_start, cluster_end, 1);
else
ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
from, to, 0);
if (ret) {
mlog_errno(ret);
goto out;
}
src = buf->ops->map(sp->s_pipe, buf, 1);
dst = kmap_atomic(wc->w_this_page, KM_USER1);
memcpy(dst + from, src + src_from, bytes);
kunmap_atomic(wc->w_this_page, KM_USER1);
buf->ops->unmap(sp->s_pipe, buf, src);
wc->w_finished_copy = 1;
*ret_from = from;
*ret_to = to;
out:
return bytes ? (unsigned int)bytes : ret;
}
/*
* This will copy user data from the iovec in the buffered write
* context.
*/
int ocfs2_map_and_write_user_data(struct inode *inode,
struct ocfs2_write_ctxt *wc, u64 *p_blkno,
unsigned int *ret_from, unsigned int *ret_to)
{
int ret;
unsigned int to, from, cluster_start, cluster_end;
unsigned long bytes, src_from;
char *dst;
struct ocfs2_buffered_write_priv *bp = wc->w_private;
const struct iovec *cur_iov = bp->b_cur_iov;
char __user *buf;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start,
&cluster_end);
buf = cur_iov->iov_base + bp->b_cur_off;
src_from = (unsigned long)buf & ~PAGE_CACHE_MASK;
from = wc->w_pos & (PAGE_CACHE_SIZE - 1);
/*
* This is a lot of comparisons, but it reads quite
* easily, which is important here.
*/
/* Stay within the src page */
bytes = PAGE_SIZE - src_from;
/* Stay within the vector */
bytes = min(bytes,
(unsigned long)(cur_iov->iov_len - bp->b_cur_off));
/* Stay within count */
bytes = min(bytes, (unsigned long)wc->w_count);
/*
* For clustersize > page size, just stay within
* target page, otherwise we have to calculate pos
* within the cluster and obey the rightmost
* boundary.
*/
if (wc->w_large_pages) {
/*
* For cluster size < page size, we have to
* calculate pos within the cluster and obey
* the rightmost boundary.
*/
bytes = min(bytes, (unsigned long)(osb->s_clustersize
- (wc->w_pos & (osb->s_clustersize - 1))));
} else {
/*
* cluster size > page size is the most common
* case - we just stay within the target page
* boundary.
*/
bytes = min(bytes, PAGE_CACHE_SIZE - from);
}
to = from + bytes;
BUG_ON(from > PAGE_CACHE_SIZE);
BUG_ON(to > PAGE_CACHE_SIZE);
BUG_ON(from < cluster_start);
BUG_ON(to > cluster_end);
if (wc->w_this_page_new)
ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
cluster_start, cluster_end, 1);
else
ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
from, to, 0);
if (ret) {
mlog_errno(ret);
goto out;
}
dst = kmap(wc->w_this_page);
memcpy(dst + from, bp->b_src_buf + src_from, bytes);
kunmap(wc->w_this_page);
/*
* XXX: This is slow, but simple. The caller of
* ocfs2_buffered_write_cluster() is responsible for
* passing through the iovecs, so it's difficult to
* predict what our next step is in here after our
* initial write. A future version should be pushing
* that iovec manipulation further down.
*
* By setting this, we indicate that a copy from user
* data was done, and subsequent calls for this
* cluster will skip copying more data.
*/
wc->w_finished_copy = 1;
*ret_from = from;
*ret_to = to;
out:
return bytes ? (unsigned int)bytes : ret;
}
/*
* Map, fill and write a page to disk.
*
* The work of copying data is done via callback. Newly allocated
* pages which don't take user data will be zero'd (set 'new' to
* indicate an allocating write)
*
* Returns a negative error code or the number of bytes copied into
* the page.
*/
static int ocfs2_write_data_page(struct inode *inode, handle_t *handle,
u64 *p_blkno, struct page *page,
struct ocfs2_write_ctxt *wc, int new)
{
int ret, copied = 0;
unsigned int from = 0, to = 0;
unsigned int cluster_start, cluster_end;
unsigned int zero_from = 0, zero_to = 0;
ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), wc->w_cpos,
&cluster_start, &cluster_end);
if ((wc->w_pos >> PAGE_CACHE_SHIFT) == page->index
&& !wc->w_finished_copy) {
wc->w_this_page = page;
wc->w_this_page_new = new;
ret = wc->w_write_data_page(inode, wc, p_blkno, &from, &to);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
copied = ret;
zero_from = from;
zero_to = to;
if (new) {
from = cluster_start;
to = cluster_end;
}
} else {
/*
* If we haven't allocated the new page yet, we
* shouldn't be writing it out without copying user
* data. This is likely a math error from the caller.
*/
BUG_ON(!new);
from = cluster_start;
to = cluster_end;
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
cluster_start, cluster_end, 1);
if (ret) {
mlog_errno(ret);
goto out;
}
}
/*
* Parts of newly allocated pages need to be zero'd.
*
* Above, we have also rewritten 'to' and 'from' - as far as
* the rest of the function is concerned, the entire cluster
* range inside of a page needs to be written.
*
* We can skip this if the page is up to date - it's already
* been zero'd from being read in as a hole.
*/
if (new && !PageUptodate(page))
ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
wc->w_cpos, zero_from, zero_to);
flush_dcache_page(page);
if (ocfs2_should_order_data(inode)) {
ret = walk_page_buffers(handle,
page_buffers(page),
from, to, NULL,
ocfs2_journal_dirty_data);
if (ret < 0)
mlog_errno(ret);
}
/*
* We don't use generic_commit_write() because we need to
* handle our own i_size update.
*/
ret = block_commit_write(page, from, to);
if (ret)
mlog_errno(ret);
out:
return copied ? copied : ret;
}
/*
* Do the actual write of some data into an inode. Optionally allocate
* in order to fulfill the write.
*
* cpos is the logical cluster offset within the file to write at
*
* 'phys' is the physical mapping of that offset. a 'phys' value of
* zero indicates that allocation is required. In this case, data_ac
* and meta_ac should be valid (meta_ac can be null if metadata
* allocation isn't required).
*/
static ssize_t ocfs2_write(struct file *file, u32 phys, handle_t *handle,
struct buffer_head *di_bh,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_write_ctxt *wc)
{
int ret, i, numpages = 1, new;
unsigned int copied = 0;
u32 tmp_pos;
u64 v_blkno, p_blkno;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
unsigned long index, start;
struct page **cpages;
new = phys == 0 ? 1 : 0;
/*
* Figure out how many pages we'll be manipulating here. For
* non allocating write, we just change the one
* page. Otherwise, we'll need a whole clusters worth.
*/
if (new)
numpages = ocfs2_pages_per_cluster(inode->i_sb);
cpages = kzalloc(sizeof(*cpages) * numpages, GFP_NOFS);
if (!cpages) {
ret = -ENOMEM;
mlog_errno(ret);
return ret;
}
/*
* Fill our page array first. That way we've grabbed enough so
* that we can zero and flush if we error after adding the
* extent.
*/
if (new) {
start = ocfs2_align_clusters_to_page_index(inode->i_sb,
wc->w_cpos);
v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, wc->w_cpos);
} else {
start = wc->w_pos >> PAGE_CACHE_SHIFT;
v_blkno = wc->w_pos >> inode->i_sb->s_blocksize_bits;
}
for(i = 0; i < numpages; i++) {
index = start + i;
cpages[i] = find_or_create_page(mapping, index, GFP_NOFS);
if (!cpages[i]) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
}
if (new) {
/*
* This is safe to call with the page locks - it won't take
* any additional semaphores or cluster locks.
*/
tmp_pos = wc->w_cpos;
ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode,
&tmp_pos, 1, di_bh, handle,
data_ac, meta_ac, NULL);
/*
* This shouldn't happen because we must have already
* calculated the correct meta data allocation required. The
* internal tree allocation code should know how to increase
* transaction credits itself.
*
* If need be, we could handle -EAGAIN for a
* RESTART_TRANS here.
*/
mlog_bug_on_msg(ret == -EAGAIN,
"Inode %llu: EAGAIN return during allocation.\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
NULL);
if (ret < 0) {
/*
* XXX: Should we go readonly here?
*/
mlog_errno(ret);
goto out;
}
BUG_ON(p_blkno == 0);
for(i = 0; i < numpages; i++) {
ret = ocfs2_write_data_page(inode, handle, &p_blkno, cpages[i],
wc, new);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
copied += ret;
}
out:
for(i = 0; i < numpages; i++) {
unlock_page(cpages[i]);
mark_page_accessed(cpages[i]);
page_cache_release(cpages[i]);
}
kfree(cpages);
return copied ? copied : ret;
}
static void ocfs2_write_ctxt_init(struct ocfs2_write_ctxt *wc,
struct ocfs2_super *osb, loff_t pos,
size_t count, ocfs2_page_writer *cb,
void *cb_priv)
{
wc->w_count = count;
wc->w_pos = pos;
wc->w_cpos = wc->w_pos >> osb->s_clustersize_bits;
wc->w_finished_copy = 0;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
wc->w_large_pages = 1;
else
wc->w_large_pages = 0;
wc->w_write_data_page = cb;
wc->w_private = cb_priv;
}
/*
* Write a cluster to an inode. The cluster may not be allocated yet,
* in which case it will be. This only exists for buffered writes -
* O_DIRECT takes a more "traditional" path through the kernel.
*
* The caller is responsible for incrementing pos, written counts, etc
*
* For file systems that don't support sparse files, pre-allocation
* and page zeroing up until cpos should be done prior to this
* function call.
*
* Callers should be holding i_sem, and the rw cluster lock.
*
* Returns the number of user bytes written, or less than zero for
* error.
*/
ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos,
size_t count, ocfs2_page_writer *actor,
void *priv)
{
int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
ssize_t written = 0;
u32 phys;
struct inode *inode = file->f_mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct buffer_head *di_bh = NULL;
struct ocfs2_dinode *di;
struct ocfs2_alloc_context *data_ac = NULL;
struct ocfs2_alloc_context *meta_ac = NULL;
handle_t *handle;
struct ocfs2_write_ctxt wc;
ocfs2_write_ctxt_init(&wc, osb, pos, count, actor, priv);
ret = ocfs2_meta_lock(inode, &di_bh, 1);
if (ret) {
mlog_errno(ret);
goto out;
}
di = (struct ocfs2_dinode *)di_bh->b_data;
/*
* Take alloc sem here to prevent concurrent lookups. That way
* the mapping, zeroing and tree manipulation within
* ocfs2_write() will be safe against ->readpage(). This
* should also serve to lock out allocation from a shared
* writeable region.
*/
down_write(&OCFS2_I(inode)->ip_alloc_sem);
ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL, NULL);
if (ret) {
mlog_errno(ret);
goto out_meta;
}
/* phys == 0 means that allocation is required. */
if (phys == 0) {
ret = ocfs2_lock_allocators(inode, di, 1, &data_ac, &meta_ac);
if (ret) {
mlog_errno(ret);
goto out_meta;
}
credits = ocfs2_calc_extend_credits(inode->i_sb, di, 1);
}
ret = ocfs2_data_lock(inode, 1);
if (ret) {
mlog_errno(ret);
goto out_meta;
}
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out_data;
}
written = ocfs2_write(file, phys, handle, di_bh, data_ac,
meta_ac, &wc);
if (written < 0) {
ret = written;
mlog_errno(ret);
goto out_commit;
}
ret = ocfs2_journal_access(handle, inode, di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
pos += written;
if (pos > inode->i_size) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
}
inode->i_blocks = ocfs2_inode_sector_count(inode);
di->i_size = cpu_to_le64((u64)i_size_read(inode));
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
ret = ocfs2_journal_dirty(handle, di_bh);
if (ret)
mlog_errno(ret);
out_commit:
ocfs2_commit_trans(osb, handle);
out_data:
ocfs2_data_unlock(inode, 1);
out_meta:
up_write(&OCFS2_I(inode)->ip_alloc_sem);
ocfs2_meta_unlock(inode, 1);
out:
brelse(di_bh);
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
return written ? written : ret;
}
const struct address_space_operations ocfs2_aops = {
.readpage = ocfs2_readpage,
.writepage = ocfs2_writepage,
.bmap = ocfs2_bmap,
.sync_page = block_sync_page,
.direct_IO = ocfs2_direct_IO,
.invalidatepage = ocfs2_invalidatepage,
.releasepage = ocfs2_releasepage,
.migratepage = buffer_migrate_page,
};
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