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OpenCloudOS-Kernel/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;
clear_buffer_new(bh);
/*
* 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 (new)
set_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) &&
!buffer_new(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 {
block_end = block_start + bsize;
if (block_end <= from)
goto next_bh;
if (block_start >= to)
break;
zero_user_page(page, block_start, bh->b_size, 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;
}
#if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
#define OCFS2_MAX_CTXT_PAGES 1
#else
#define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
#endif
#define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
/*
* Describe the state of a single cluster to be written to.
*/
struct ocfs2_write_cluster_desc {
u32 c_cpos;
u32 c_phys;
/*
* Give this a unique field because c_phys eventually gets
* filled.
*/
unsigned c_new;
unsigned c_unwritten;
};
static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d)
{
return d->c_new || d->c_unwritten;
}
struct ocfs2_write_ctxt {
/* Logical cluster position / len of write */
u32 w_cpos;
u32 w_clen;
struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
/*
* This is true if page_size > cluster_size.
*
* It triggers a set of special cases during write which might
* have to deal with allocating writes to partial pages.
*/
unsigned int w_large_pages;
/*
* Pages involved in this write.
*
* w_target_page is the page being written to by the user.
*
* w_pages is an array of pages which always contains
* w_target_page, and in the case of an allocating write with
* page_size < cluster size, it will contain zero'd and mapped
* pages adjacent to w_target_page which need to be written
* out in so that future reads from that region will get
* zero's.
*/
struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
unsigned int w_num_pages;
struct page *w_target_page;
/*
* ocfs2_write_end() uses this to know what the real range to
* write in the target should be.
*/
unsigned int w_target_from;
unsigned int w_target_to;
/*
* We could use journal_current_handle() but this is cleaner,
* IMHO -Mark
*/
handle_t *w_handle;
struct buffer_head *w_di_bh;
struct ocfs2_cached_dealloc_ctxt w_dealloc;
};
static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
{
int i;
for(i = 0; i < wc->w_num_pages; i++) {
if (wc->w_pages[i] == NULL)
continue;
unlock_page(wc->w_pages[i]);
mark_page_accessed(wc->w_pages[i]);
page_cache_release(wc->w_pages[i]);
}
brelse(wc->w_di_bh);
kfree(wc);
}
static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
struct ocfs2_super *osb, loff_t pos,
unsigned len, struct buffer_head *di_bh)
{
struct ocfs2_write_ctxt *wc;
wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
if (!wc)
return -ENOMEM;
wc->w_cpos = pos >> osb->s_clustersize_bits;
wc->w_clen = ocfs2_clusters_for_bytes(osb->sb, len);
get_bh(di_bh);
wc->w_di_bh = di_bh;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
wc->w_large_pages = 1;
else
wc->w_large_pages = 0;
ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
*wcp = wc;
return 0;
}
/*
* If a page has any new buffers, zero them out here, and mark them uptodate
* and dirty so they'll be written out (in order to prevent uninitialised
* block data from leaking). And clear the new bit.
*/
static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
{
unsigned int block_start, block_end;
struct buffer_head *head, *bh;
BUG_ON(!PageLocked(page));
if (!page_has_buffers(page))
return;
bh = head = page_buffers(page);
block_start = 0;
do {
block_end = block_start + bh->b_size;
if (buffer_new(bh)) {
if (block_end > from && block_start < to) {
if (!PageUptodate(page)) {
unsigned start, end;
start = max(from, block_start);
end = min(to, block_end);
zero_user_page(page, start, end - start, KM_USER0);
set_buffer_uptodate(bh);
}
clear_buffer_new(bh);
mark_buffer_dirty(bh);
}
}
block_start = block_end;
bh = bh->b_this_page;
} while (bh != head);
}
/*
* Only called when we have a failure during allocating write to write
* zero's to the newly allocated region.
*/
static void ocfs2_write_failure(struct inode *inode,
struct ocfs2_write_ctxt *wc,
loff_t user_pos, unsigned user_len)
{
int i;
unsigned from, to;
struct page *tmppage;
ocfs2_zero_new_buffers(wc->w_target_page, user_pos, user_len);
if (wc->w_large_pages) {
from = wc->w_target_from;
to = wc->w_target_to;
} else {
from = 0;
to = PAGE_CACHE_SIZE;
}
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
if (ocfs2_should_order_data(inode))
walk_page_buffers(wc->w_handle, page_buffers(tmppage),
from, to, NULL,
ocfs2_journal_dirty_data);
block_commit_write(tmppage, from, to);
}
}
static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
struct ocfs2_write_ctxt *wc,
struct page *page, u32 cpos,
loff_t user_pos, unsigned user_len,
int new)
{
int ret;
unsigned int map_from = 0, map_to = 0;
unsigned int cluster_start, cluster_end;
unsigned int user_data_from = 0, user_data_to = 0;
ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
&cluster_start, &cluster_end);
if (page == wc->w_target_page) {
map_from = user_pos & (PAGE_CACHE_SIZE - 1);
map_to = map_from + user_len;
if (new)
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
cluster_start, cluster_end,
new);
else
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
map_from, map_to, new);
if (ret) {
mlog_errno(ret);
goto out;
}
user_data_from = map_from;
user_data_to = map_to;
if (new) {
map_from = cluster_start;
map_to = cluster_end;
}
wc->w_target_from = map_from;
wc->w_target_to = map_to;
} 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);
map_from = cluster_start;
map_to = cluster_end;
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
cluster_start, cluster_end, new);
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),
cpos, user_data_from, user_data_to);
flush_dcache_page(page);
out:
return ret;
}
/*
* This function will only grab one clusters worth of pages.
*/
static int ocfs2_grab_pages_for_write(struct address_space *mapping,
struct ocfs2_write_ctxt *wc,
u32 cpos, loff_t user_pos, int new,
struct page *mmap_page)
{
int ret = 0, i;
unsigned long start, target_index, index;
struct inode *inode = mapping->host;
target_index = user_pos >> PAGE_CACHE_SHIFT;
/*
* 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) {
wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
} else {
wc->w_num_pages = 1;
start = target_index;
}
for(i = 0; i < wc->w_num_pages; i++) {
index = start + i;
if (index == target_index && mmap_page) {
/*
* ocfs2_pagemkwrite() is a little different
* and wants us to directly use the page
* passed in.
*/
lock_page(mmap_page);
if (mmap_page->mapping != mapping) {
unlock_page(mmap_page);
/*
* Sanity check - the locking in
* ocfs2_pagemkwrite() should ensure
* that this code doesn't trigger.
*/
ret = -EINVAL;
mlog_errno(ret);
goto out;
}
page_cache_get(mmap_page);
wc->w_pages[i] = mmap_page;
} else {
wc->w_pages[i] = find_or_create_page(mapping, index,
GFP_NOFS);
if (!wc->w_pages[i]) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
}
if (index == target_index)
wc->w_target_page = wc->w_pages[i];
}
out:
return ret;
}
/*
* Prepare a single cluster for write one cluster into the file.
*/
static int ocfs2_write_cluster(struct address_space *mapping,
u32 phys, unsigned int unwritten,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_write_ctxt *wc, u32 cpos,
loff_t user_pos, unsigned user_len)
{
int ret, i, new, should_zero = 0;
u64 v_blkno, p_blkno;
struct inode *inode = mapping->host;
new = phys == 0 ? 1 : 0;
if (new || unwritten)
should_zero = 1;
if (new) {
u32 tmp_pos;
/*
* This is safe to call with the page locks - it won't take
* any additional semaphores or cluster locks.
*/
tmp_pos = cpos;
ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode,
&tmp_pos, 1, 0, wc->w_di_bh,
wc->w_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;
}
} else if (unwritten) {
ret = ocfs2_mark_extent_written(inode, wc->w_di_bh,
wc->w_handle, cpos, 1, phys,
meta_ac, &wc->w_dealloc);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
if (should_zero)
v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
else
v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
/*
* The only reason this should fail is due to an inability to
* find the extent added.
*/
ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
NULL);
if (ret < 0) {
ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
"at logical block %llu",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)v_blkno);
goto out;
}
BUG_ON(p_blkno == 0);
for(i = 0; i < wc->w_num_pages; i++) {
int tmpret;
tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
wc->w_pages[i], cpos,
user_pos, user_len,
should_zero);
if (tmpret) {
mlog_errno(tmpret);
if (ret == 0)
tmpret = ret;
}
}
/*
* We only have cleanup to do in case of allocating write.
*/
if (ret && new)
ocfs2_write_failure(inode, wc, user_pos, user_len);
out:
return ret;
}
static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_write_ctxt *wc,
loff_t pos, unsigned len)
{
int ret, i;
struct ocfs2_write_cluster_desc *desc;
for (i = 0; i < wc->w_clen; i++) {
desc = &wc->w_desc[i];
ret = ocfs2_write_cluster(mapping, desc->c_phys,
desc->c_unwritten, data_ac, meta_ac,
wc, desc->c_cpos, pos, len);
if (ret) {
mlog_errno(ret);
goto out;
}
}
ret = 0;
out:
return ret;
}
/*
* ocfs2_write_end() wants to know which parts of the target page it
* should complete the write on. It's easiest to compute them ahead of
* time when a more complete view of the write is available.
*/
static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
struct ocfs2_write_ctxt *wc,
loff_t pos, unsigned len, int alloc)
{
struct ocfs2_write_cluster_desc *desc;
wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
wc->w_target_to = wc->w_target_from + len;
if (alloc == 0)
return;
/*
* Allocating write - we may have different boundaries based
* on page size and cluster size.
*
* NOTE: We can no longer compute one value from the other as
* the actual write length and user provided length may be
* different.
*/
if (wc->w_large_pages) {
/*
* We only care about the 1st and last cluster within
* our range and whether they should be zero'd or not. Either
* value may be extended out to the start/end of a
* newly allocated cluster.
*/
desc = &wc->w_desc[0];
if (ocfs2_should_zero_cluster(desc))
ocfs2_figure_cluster_boundaries(osb,
desc->c_cpos,
&wc->w_target_from,
NULL);
desc = &wc->w_desc[wc->w_clen - 1];
if (ocfs2_should_zero_cluster(desc))
ocfs2_figure_cluster_boundaries(osb,
desc->c_cpos,
NULL,
&wc->w_target_to);
} else {
wc->w_target_from = 0;
wc->w_target_to = PAGE_CACHE_SIZE;
}
}
/*
* Populate each single-cluster write descriptor in the write context
* with information about the i/o to be done.
*
* Returns the number of clusters that will have to be allocated, as
* well as a worst case estimate of the number of extent records that
* would have to be created during a write to an unwritten region.
*/
static int ocfs2_populate_write_desc(struct inode *inode,
struct ocfs2_write_ctxt *wc,
unsigned int *clusters_to_alloc,
unsigned int *extents_to_split)
{
int ret;
struct ocfs2_write_cluster_desc *desc;
unsigned int num_clusters = 0;
unsigned int ext_flags = 0;
u32 phys = 0;
int i;
*clusters_to_alloc = 0;
*extents_to_split = 0;
for (i = 0; i < wc->w_clen; i++) {
desc = &wc->w_desc[i];
desc->c_cpos = wc->w_cpos + i;
if (num_clusters == 0) {
/*
* Need to look up the next extent record.
*/
ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
&num_clusters, &ext_flags);
if (ret) {
mlog_errno(ret);
goto out;
}
/*
* Assume worst case - that we're writing in
* the middle of the extent.
*
* We can assume that the write proceeds from
* left to right, in which case the extent
* insert code is smart enough to coalesce the
* next splits into the previous records created.
*/
if (ext_flags & OCFS2_EXT_UNWRITTEN)
*extents_to_split = *extents_to_split + 2;
} else if (phys) {
/*
* Only increment phys if it doesn't describe
* a hole.
*/
phys++;
}
desc->c_phys = phys;
if (phys == 0) {
desc->c_new = 1;
*clusters_to_alloc = *clusters_to_alloc + 1;
}
if (ext_flags & OCFS2_EXT_UNWRITTEN)
desc->c_unwritten = 1;
num_clusters--;
}
ret = 0;
out:
return ret;
}
int ocfs2_write_begin_nolock(struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata,
struct buffer_head *di_bh, struct page *mmap_page)
{
int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
unsigned int clusters_to_alloc, extents_to_split;
struct ocfs2_write_ctxt *wc;
struct inode *inode = mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_dinode *di;
struct ocfs2_alloc_context *data_ac = NULL;
struct ocfs2_alloc_context *meta_ac = NULL;
handle_t *handle;
ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
if (ret) {
mlog_errno(ret);
return ret;
}
ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
&extents_to_split);
if (ret) {
mlog_errno(ret);
goto out;
}
di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
/*
* We set w_target_from, w_target_to here so that
* ocfs2_write_end() knows which range in the target page to
* write out. An allocation requires that we write the entire
* cluster range.
*/
if (clusters_to_alloc || extents_to_split) {
/*
* XXX: We are stretching the limits of
* ocfs2_lock_allocators(). It greatly over-estimates
* the work to be done.
*/
ret = ocfs2_lock_allocators(inode, di, clusters_to_alloc,
extents_to_split, &data_ac, &meta_ac);
if (ret) {
mlog_errno(ret);
goto out;
}
credits = ocfs2_calc_extend_credits(inode->i_sb, di,
clusters_to_alloc);
}
ocfs2_set_target_boundaries(osb, wc, pos, len,
clusters_to_alloc + extents_to_split);
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out;
}
wc->w_handle = handle;
/*
* We don't want this to fail in ocfs2_write_end(), so do it
* here.
*/
ret = ocfs2_journal_access(handle, inode, wc->w_di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
/*
* 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.
*/
ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
clusters_to_alloc + extents_to_split,
mmap_page);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
len);
if (ret) {
mlog_errno(ret);
goto out_commit;
}
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
*pagep = wc->w_target_page;
*fsdata = wc;
return 0;
out_commit:
ocfs2_commit_trans(osb, handle);
out:
ocfs2_free_write_ctxt(wc);
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
return ret;
}
int ocfs2_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
struct buffer_head *di_bh = NULL;
struct inode *inode = mapping->host;
ret = ocfs2_meta_lock(inode, &di_bh, 1);
if (ret) {
mlog_errno(ret);
return ret;
}
/*
* 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_data_lock(inode, 1);
if (ret) {
mlog_errno(ret);
goto out_fail;
}
ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
fsdata, di_bh, NULL);
if (ret) {
mlog_errno(ret);
goto out_fail_data;
}
brelse(di_bh);
return 0;
out_fail_data:
ocfs2_data_unlock(inode, 1);
out_fail:
up_write(&OCFS2_I(inode)->ip_alloc_sem);
brelse(di_bh);
ocfs2_meta_unlock(inode, 1);
return ret;
}
int ocfs2_write_end_nolock(struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
int i;
unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
struct inode *inode = mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_write_ctxt *wc = fsdata;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
handle_t *handle = wc->w_handle;
struct page *tmppage;
if (unlikely(copied < len)) {
if (!PageUptodate(wc->w_target_page))
copied = 0;
ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
start+len);
}
flush_dcache_page(wc->w_target_page);
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
if (tmppage == wc->w_target_page) {
from = wc->w_target_from;
to = wc->w_target_to;
BUG_ON(from > PAGE_CACHE_SIZE ||
to > PAGE_CACHE_SIZE ||
to < from);
} else {
/*
* Pages adjacent to the target (if any) imply
* a hole-filling write in which case we want
* to flush their entire range.
*/
from = 0;
to = PAGE_CACHE_SIZE;
}
if (ocfs2_should_order_data(inode))
walk_page_buffers(wc->w_handle, page_buffers(tmppage),
from, to, NULL,
ocfs2_journal_dirty_data);
block_commit_write(tmppage, from, to);
}
pos += copied;
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);
ocfs2_journal_dirty(handle, wc->w_di_bh);
ocfs2_commit_trans(osb, handle);
ocfs2_run_deallocs(osb, &wc->w_dealloc);
ocfs2_free_write_ctxt(wc);
return copied;
}
int ocfs2_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
int ret;
struct inode *inode = mapping->host;
ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
ocfs2_data_unlock(inode, 1);
up_write(&OCFS2_I(inode)->ip_alloc_sem);
ocfs2_meta_unlock(inode, 1);
return 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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