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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>
#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 "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)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;
u64 p_blkno, past_eof;
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;
}
/* this can happen if another node truncs after our extend! */
spin_lock(&OCFS2_I(inode)->ip_lock);
if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
OCFS2_I(inode)->ip_clusters))
err = -EIO;
spin_unlock(&OCFS2_I(inode)->ip_lock);
if (err)
goto bail;
err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
NULL);
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;
}
map_bh(bh_result, inode->i_sb, p_blkno);
if (bh_result->b_blocknr == 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);
}
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, NULL, 0, page);
if (ret != 0) {
if (ret == AOP_TRUNCATED_PAGE)
unlock = 0;
mlog_errno(ret);
goto out;
}
down_read(&OCFS2_I(inode)->ip_alloc_sem);
/*
* 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)) {
char *addr = kmap(page);
memset(addr, 0, PAGE_SIZE);
flush_dcache_page(page);
kunmap(page);
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);
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 can also be called from ocfs2_write_zero_page() which has done
* it's own cluster locking. */
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;
}
/*
* ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
* from loopback. It must be able to perform its own locking around
* ocfs2_get_block().
*/
static int ocfs2_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
struct inode *inode = page->mapping->host;
int ret;
mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
if (ret != 0) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_prepare_write_nolock(inode, page, from, to);
ocfs2_meta_unlock(inode, 0);
out:
mlog_exit(ret);
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 */
static 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;
}
struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
struct page *page,
unsigned from,
unsigned to)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_journal_handle *handle = NULL;
int ret = 0;
handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS);
if (!handle) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
if (ocfs2_should_order_data(inode)) {
ret = walk_page_buffers(handle->k_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(handle);
handle = ERR_PTR(ret);
}
return handle;
}
static int ocfs2_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
int ret;
struct buffer_head *di_bh = NULL;
struct inode *inode = page->mapping->host;
struct ocfs2_journal_handle *handle = NULL;
struct ocfs2_dinode *di;
mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
/* NOTE: ocfs2_file_aio_write has ensured that it's safe for
* us to continue here without rechecking the I/O against
* changed inode values.
*
* 1) We're currently holding the inode alloc lock, so no
* nodes can change it underneath us.
*
* 2) We've had to take the metadata lock at least once
* already to check for extending writes, suid removal, etc.
* The meta data update code then ensures that we don't get a
* stale inode allocation image (i_size, i_clusters, etc).
*/
ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, 1, page);
if (ret != 0) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_data_lock_with_page(inode, 1, page);
if (ret != 0) {
mlog_errno(ret);
goto out_unlock_meta;
}
handle = ocfs2_start_walk_page_trans(inode, page, from, to);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
goto out_unlock_data;
}
/* Mark our buffer early. We'd rather catch this error up here
* as opposed to after a successful commit_write which would
* require us to set back inode->i_size. */
ret = ocfs2_journal_access(handle, inode, di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret < 0) {
mlog_errno(ret);
goto out_commit;
}
/* might update i_size */
ret = generic_commit_write(file, page, from, to);
if (ret < 0) {
mlog_errno(ret);
goto out_commit;
}
di = (struct ocfs2_dinode *)di_bh->b_data;
/* ocfs2_mark_inode_dirty() is too heavy to use here. */
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);
inode->i_blocks = ocfs2_align_bytes_to_sectors((u64)(i_size_read(inode)));
di->i_size = cpu_to_le64((u64)i_size_read(inode));
ret = ocfs2_journal_dirty(handle, di_bh);
if (ret < 0) {
mlog_errno(ret);
goto out_commit;
}
out_commit:
ocfs2_commit_trans(handle);
out_unlock_data:
ocfs2_data_unlock(inode, 1);
out_unlock_meta:
ocfs2_meta_unlock(inode, 1);
out:
if (di_bh)
brelse(di_bh);
mlog_exit(ret);
return ret;
}
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, 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, 1, &p_blkno,
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 vbo_max; /* file offset, max_blocks from iblock */
u64 p_blkno;
int contig_blocks;
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. */
vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;
spin_lock(&OCFS2_I(inode)->ip_lock);
if ((iblock + max_blocks) >
ocfs2_clusters_to_blocks(inode->i_sb,
OCFS2_I(inode)->ip_clusters)) {
spin_unlock(&OCFS2_I(inode)->ip_lock);
ret = -EIO;
goto bail;
}
spin_unlock(&OCFS2_I(inode)->ip_lock);
/* This figures out the size of the next contiguous block, and
* our logical offset */
ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
&contig_blocks);
if (ret) {
mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
(unsigned long long)iblock);
ret = -EIO;
goto bail;
}
map_bh(bh_result, inode->i_sb, p_blkno);
/* 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_dentry->d_inode;
/* 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);
up_read(&inode->i_alloc_sem);
ocfs2_rw_unlock(inode, 0);
}
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_dentry->d_inode->i_mapping->host;
int ret;
mlog_entry_void();
/*
* 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;
}
const struct address_space_operations ocfs2_aops = {
.readpage = ocfs2_readpage,
.writepage = ocfs2_writepage,
.prepare_write = ocfs2_prepare_write,
.commit_write = ocfs2_commit_write,
.bmap = ocfs2_bmap,
.sync_page = block_sync_page,
.direct_IO = ocfs2_direct_IO
};
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