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inode.c
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/*
* Copyright (C) 2005, 2006
* Avishay Traeger ([email protected])
* Copyright (C) 2008, 2009
* Boaz Harrosh <[email protected]>
*
* Copyrights for code taken from ext2:
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card ([email protected])
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
* from
* linux/fs/minix/inode.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* This file is part of exofs.
*
* exofs 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. Since it is based on ext2, and the only
* valid version of GPL for the Linux kernel is version 2, the only valid
* version of GPL for exofs is version 2.
*
* exofs 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 exofs; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/slab.h>
#include "exofs.h"
#define EXOFS_DBGMSG2(M...) do {} while (0)
unsigned exofs_max_io_pages(struct ore_layout *layout,
unsigned expected_pages)
{
unsigned pages = min_t(unsigned, expected_pages,
layout->max_io_length / PAGE_SIZE);
return pages;
}
struct page_collect {
struct exofs_sb_info *sbi;
struct inode *inode;
unsigned expected_pages;
struct ore_io_state *ios;
struct page **pages;
unsigned alloc_pages;
unsigned nr_pages;
unsigned long length;
loff_t pg_first; /* keep 64bit also in 32-arches */
bool read_4_write; /* This means two things: that the read is sync
* And the pages should not be unlocked.
*/
struct page *that_locked_page;
};
static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
struct inode *inode)
{
struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
pcol->sbi = sbi;
pcol->inode = inode;
pcol->expected_pages = expected_pages;
pcol->ios = NULL;
pcol->pages = NULL;
pcol->alloc_pages = 0;
pcol->nr_pages = 0;
pcol->length = 0;
pcol->pg_first = -1;
pcol->read_4_write = false;
pcol->that_locked_page = NULL;
}
static void _pcol_reset(struct page_collect *pcol)
{
pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
pcol->pages = NULL;
pcol->alloc_pages = 0;
pcol->nr_pages = 0;
pcol->length = 0;
pcol->pg_first = -1;
pcol->ios = NULL;
pcol->that_locked_page = NULL;
/* this is probably the end of the loop but in writes
* it might not end here. don't be left with nothing
*/
if (!pcol->expected_pages)
pcol->expected_pages =
exofs_max_io_pages(&pcol->sbi->layout, ~0);
}
static int pcol_try_alloc(struct page_collect *pcol)
{
unsigned pages;
/* TODO: easily support bio chaining */
pages = exofs_max_io_pages(&pcol->sbi->layout, pcol->expected_pages);
for (; pages; pages >>= 1) {
pcol->pages = kmalloc_array(pages, sizeof(struct page *),
GFP_KERNEL);
if (likely(pcol->pages)) {
pcol->alloc_pages = pages;
return 0;
}
}
EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
pcol->expected_pages);
return -ENOMEM;
}
static void pcol_free(struct page_collect *pcol)
{
kfree(pcol->pages);
pcol->pages = NULL;
if (pcol->ios) {
ore_put_io_state(pcol->ios);
pcol->ios = NULL;
}
}
static int pcol_add_page(struct page_collect *pcol, struct page *page,
unsigned len)
{
if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
return -ENOMEM;
pcol->pages[pcol->nr_pages++] = page;
pcol->length += len;
return 0;
}
enum {PAGE_WAS_NOT_IN_IO = 17};
static int update_read_page(struct page *page, int ret)
{
switch (ret) {
case 0:
/* Everything is OK */
SetPageUptodate(page);
if (PageError(page))
ClearPageError(page);
break;
case -EFAULT:
/* In this case we were trying to read something that wasn't on
* disk yet - return a page full of zeroes. This should be OK,
* because the object should be empty (if there was a write
* before this read, the read would be waiting with the page
* locked */
clear_highpage(page);
SetPageUptodate(page);
if (PageError(page))
ClearPageError(page);
EXOFS_DBGMSG("recovered read error\n");
/* fall through */
case PAGE_WAS_NOT_IN_IO:
ret = 0; /* recovered error */
break;
default:
SetPageError(page);
}
return ret;
}
static void update_write_page(struct page *page, int ret)
{
if (unlikely(ret == PAGE_WAS_NOT_IN_IO))
return; /* don't pass start don't collect $200 */
if (ret) {
mapping_set_error(page->mapping, ret);
SetPageError(page);
}
end_page_writeback(page);
}
/* Called at the end of reads, to optionally unlock pages and update their
* status.
*/
static int __readpages_done(struct page_collect *pcol)
{
int i;
u64 good_bytes;
u64 length = 0;
int ret = ore_check_io(pcol->ios, NULL);
if (likely(!ret)) {
good_bytes = pcol->length;
ret = PAGE_WAS_NOT_IN_IO;
} else {
good_bytes = 0;
}
EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
" length=0x%lx nr_pages=%u\n",
pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
pcol->nr_pages);
for (i = 0; i < pcol->nr_pages; i++) {
struct page *page = pcol->pages[i];
struct inode *inode = page->mapping->host;
int page_stat;
if (inode != pcol->inode)
continue; /* osd might add more pages at end */
if (likely(length < good_bytes))
page_stat = 0;
else
page_stat = ret;
EXOFS_DBGMSG2(" readpages_done(0x%lx, 0x%lx) %s\n",
inode->i_ino, page->index,
page_stat ? "bad_bytes" : "good_bytes");
ret = update_read_page(page, page_stat);
if (!pcol->read_4_write)
unlock_page(page);
length += PAGE_SIZE;
}
pcol_free(pcol);
EXOFS_DBGMSG2("readpages_done END\n");
return ret;
}
/* callback of async reads */
static void readpages_done(struct ore_io_state *ios, void *p)
{
struct page_collect *pcol = p;
__readpages_done(pcol);
atomic_dec(&pcol->sbi->s_curr_pending);
kfree(pcol);
}
static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
{
int i;
for (i = 0; i < pcol->nr_pages; i++) {
struct page *page = pcol->pages[i];
if (rw == READ)
update_read_page(page, ret);
else
update_write_page(page, ret);
unlock_page(page);
}
}
static int _maybe_not_all_in_one_io(struct ore_io_state *ios,
struct page_collect *pcol_src, struct page_collect *pcol)
{
/* length was wrong or offset was not page aligned */
BUG_ON(pcol_src->nr_pages < ios->nr_pages);
if (pcol_src->nr_pages > ios->nr_pages) {
struct page **src_page;
unsigned pages_less = pcol_src->nr_pages - ios->nr_pages;
unsigned long len_less = pcol_src->length - ios->length;
unsigned i;
int ret;
/* This IO was trimmed */
pcol_src->nr_pages = ios->nr_pages;
pcol_src->length = ios->length;
/* Left over pages are passed to the next io */
pcol->expected_pages += pages_less;
pcol->nr_pages = pages_less;
pcol->length = len_less;
src_page = pcol_src->pages + pcol_src->nr_pages;
pcol->pg_first = (*src_page)->index;
ret = pcol_try_alloc(pcol);
if (unlikely(ret))
return ret;
for (i = 0; i < pages_less; ++i)
pcol->pages[i] = *src_page++;
EXOFS_DBGMSG("Length was adjusted nr_pages=0x%x "
"pages_less=0x%x expected_pages=0x%x "
"next_offset=0x%llx next_len=0x%lx\n",
pcol_src->nr_pages, pages_less, pcol->expected_pages,
pcol->pg_first * PAGE_SIZE, pcol->length);
}
return 0;
}
static int read_exec(struct page_collect *pcol)
{
struct exofs_i_info *oi = exofs_i(pcol->inode);
struct ore_io_state *ios;
struct page_collect *pcol_copy = NULL;
int ret;
if (!pcol->pages)
return 0;
if (!pcol->ios) {
int ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, true,
pcol->pg_first << PAGE_SHIFT,
pcol->length, &pcol->ios);
if (ret)
return ret;
}
ios = pcol->ios;
ios->pages = pcol->pages;
if (pcol->read_4_write) {
ore_read(pcol->ios);
return __readpages_done(pcol);
}
pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
if (!pcol_copy) {
ret = -ENOMEM;
goto err;
}
*pcol_copy = *pcol;
ios->done = readpages_done;
ios->private = pcol_copy;
/* pages ownership was passed to pcol_copy */
_pcol_reset(pcol);
ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol);
if (unlikely(ret))
goto err;
EXOFS_DBGMSG2("read_exec(0x%lx) offset=0x%llx length=0x%llx\n",
pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length));
ret = ore_read(ios);
if (unlikely(ret))
goto err;
atomic_inc(&pcol->sbi->s_curr_pending);
return 0;
err:
if (!pcol_copy) /* Failed before ownership transfer */
pcol_copy = pcol;
_unlock_pcol_pages(pcol_copy, ret, READ);
pcol_free(pcol_copy);
kfree(pcol_copy);
return ret;
}
/* readpage_strip is called either directly from readpage() or by the VFS from
* within read_cache_pages(), to add one more page to be read. It will try to
* collect as many contiguous pages as posible. If a discontinuity is
* encountered, or it runs out of resources, it will submit the previous segment
* and will start a new collection. Eventually caller must submit the last
* segment if present.
*/
static int readpage_strip(void *data, struct page *page)
{
struct page_collect *pcol = data;
struct inode *inode = pcol->inode;
struct exofs_i_info *oi = exofs_i(inode);
loff_t i_size = i_size_read(inode);
pgoff_t end_index = i_size >> PAGE_SHIFT;
size_t len;
int ret;
BUG_ON(!PageLocked(page));
/* FIXME: Just for debugging, will be removed */
if (PageUptodate(page))
EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
page->index);
pcol->that_locked_page = page;
if (page->index < end_index)
len = PAGE_SIZE;
else if (page->index == end_index)
len = i_size & ~PAGE_MASK;
else
len = 0;
if (!len || !obj_created(oi)) {
/* this will be out of bounds, or doesn't exist yet.
* Current page is cleared and the request is split
*/
clear_highpage(page);
SetPageUptodate(page);
if (PageError(page))
ClearPageError(page);
if (!pcol->read_4_write)
unlock_page(page);
EXOFS_DBGMSG("readpage_strip(0x%lx) empty page len=%zx "
"read_4_write=%d index=0x%lx end_index=0x%lx "
"splitting\n", inode->i_ino, len,
pcol->read_4_write, page->index, end_index);
return read_exec(pcol);
}
try_again:
if (unlikely(pcol->pg_first == -1)) {
pcol->pg_first = page->index;
} else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
page->index)) {
/* Discontinuity detected, split the request */
ret = read_exec(pcol);
if (unlikely(ret))
goto fail;
goto try_again;
}
if (!pcol->pages) {
ret = pcol_try_alloc(pcol);
if (unlikely(ret))
goto fail;
}
if (len != PAGE_SIZE)
zero_user(page, len, PAGE_SIZE - len);
EXOFS_DBGMSG2(" readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
inode->i_ino, page->index, len);
ret = pcol_add_page(pcol, page, len);
if (ret) {
EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
"this_len=0x%zx nr_pages=%u length=0x%lx\n",
page, len, pcol->nr_pages, pcol->length);
/* split the request, and start again with current page */
ret = read_exec(pcol);
if (unlikely(ret))
goto fail;
goto try_again;
}
return 0;
fail:
/* SetPageError(page); ??? */
unlock_page(page);
return ret;
}
static int exofs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct page_collect pcol;
int ret;
_pcol_init(&pcol, nr_pages, mapping->host);
ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
if (ret) {
EXOFS_ERR("read_cache_pages => %d\n", ret);
return ret;
}
ret = read_exec(&pcol);
if (unlikely(ret))
return ret;
return read_exec(&pcol);
}
static int _readpage(struct page *page, bool read_4_write)
{
struct page_collect pcol;
int ret;
_pcol_init(&pcol, 1, page->mapping->host);
pcol.read_4_write = read_4_write;
ret = readpage_strip(&pcol, page);
if (ret) {
EXOFS_ERR("_readpage => %d\n", ret);
return ret;
}
return read_exec(&pcol);
}
/*
* We don't need the file
*/
static int exofs_readpage(struct file *file, struct page *page)
{
return _readpage(page, false);
}
/* Callback for osd_write. All writes are asynchronous */
static void writepages_done(struct ore_io_state *ios, void *p)
{
struct page_collect *pcol = p;
int i;
u64 good_bytes;
u64 length = 0;
int ret = ore_check_io(ios, NULL);
atomic_dec(&pcol->sbi->s_curr_pending);
if (likely(!ret)) {
good_bytes = pcol->length;
ret = PAGE_WAS_NOT_IN_IO;
} else {
good_bytes = 0;
}
EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
" length=0x%lx nr_pages=%u\n",
pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
pcol->nr_pages);
for (i = 0; i < pcol->nr_pages; i++) {
struct page *page = pcol->pages[i];
struct inode *inode = page->mapping->host;
int page_stat;
if (inode != pcol->inode)
continue; /* osd might add more pages to a bio */
if (likely(length < good_bytes))
page_stat = 0;
else
page_stat = ret;
update_write_page(page, page_stat);
unlock_page(page);
EXOFS_DBGMSG2(" writepages_done(0x%lx, 0x%lx) status=%d\n",
inode->i_ino, page->index, page_stat);
length += PAGE_SIZE;
}
pcol_free(pcol);
kfree(pcol);
EXOFS_DBGMSG2("writepages_done END\n");
}
static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
{
struct page_collect *pcol = priv;
pgoff_t index = offset / PAGE_SIZE;
if (!pcol->that_locked_page ||
(pcol->that_locked_page->index != index)) {
struct page *page;
loff_t i_size = i_size_read(pcol->inode);
if (offset >= i_size) {
*uptodate = true;
EXOFS_DBGMSG2("offset >= i_size index=0x%lx\n", index);
return ZERO_PAGE(0);
}
page = find_get_page(pcol->inode->i_mapping, index);
if (!page) {
page = find_or_create_page(pcol->inode->i_mapping,
index, GFP_NOFS);
if (unlikely(!page)) {
EXOFS_DBGMSG("grab_cache_page Failed "
"index=0x%llx\n", _LLU(index));
return NULL;
}
unlock_page(page);
}
*uptodate = PageUptodate(page);
EXOFS_DBGMSG2("index=0x%lx uptodate=%d\n", index, *uptodate);
return page;
} else {
EXOFS_DBGMSG2("YES that_locked_page index=0x%lx\n",
pcol->that_locked_page->index);
*uptodate = true;
return pcol->that_locked_page;
}
}
static void __r4w_put_page(void *priv, struct page *page)
{
struct page_collect *pcol = priv;
if ((pcol->that_locked_page != page) && (ZERO_PAGE(0) != page)) {
EXOFS_DBGMSG2("index=0x%lx\n", page->index);
put_page(page);
return;
}
EXOFS_DBGMSG2("that_locked_page index=0x%lx\n",
ZERO_PAGE(0) == page ? -1 : page->index);
}
static const struct _ore_r4w_op _r4w_op = {
.get_page = &__r4w_get_page,
.put_page = &__r4w_put_page,
};
static int write_exec(struct page_collect *pcol)
{
struct exofs_i_info *oi = exofs_i(pcol->inode);
struct ore_io_state *ios;
struct page_collect *pcol_copy = NULL;
int ret;
if (!pcol->pages)
return 0;
BUG_ON(pcol->ios);
ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, false,
pcol->pg_first << PAGE_SHIFT,
pcol->length, &pcol->ios);
if (unlikely(ret))
goto err;
pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
if (!pcol_copy) {
EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
ret = -ENOMEM;
goto err;
}
*pcol_copy = *pcol;
ios = pcol->ios;
ios->pages = pcol_copy->pages;
ios->done = writepages_done;
ios->r4w = &_r4w_op;
ios->private = pcol_copy;
/* pages ownership was passed to pcol_copy */
_pcol_reset(pcol);
ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol);
if (unlikely(ret))
goto err;
EXOFS_DBGMSG2("write_exec(0x%lx) offset=0x%llx length=0x%llx\n",
pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length));
ret = ore_write(ios);
if (unlikely(ret)) {
EXOFS_ERR("write_exec: ore_write() Failed\n");
goto err;
}
atomic_inc(&pcol->sbi->s_curr_pending);
return 0;
err:
if (!pcol_copy) /* Failed before ownership transfer */
pcol_copy = pcol;
_unlock_pcol_pages(pcol_copy, ret, WRITE);
pcol_free(pcol_copy);
kfree(pcol_copy);
return ret;
}
/* writepage_strip is called either directly from writepage() or by the VFS from
* within write_cache_pages(), to add one more page to be written to storage.
* It will try to collect as many contiguous pages as possible. If a
* discontinuity is encountered or it runs out of resources it will submit the
* previous segment and will start a new collection.
* Eventually caller must submit the last segment if present.
*/
static int writepage_strip(struct page *page,
struct writeback_control *wbc_unused, void *data)
{
struct page_collect *pcol = data;
struct inode *inode = pcol->inode;
struct exofs_i_info *oi = exofs_i(inode);
loff_t i_size = i_size_read(inode);
pgoff_t end_index = i_size >> PAGE_SHIFT;
size_t len;
int ret;
BUG_ON(!PageLocked(page));
ret = wait_obj_created(oi);
if (unlikely(ret))
goto fail;
if (page->index < end_index)
/* in this case, the page is within the limits of the file */
len = PAGE_SIZE;
else {
len = i_size & ~PAGE_MASK;
if (page->index > end_index || !len) {
/* in this case, the page is outside the limits
* (truncate in progress)
*/
ret = write_exec(pcol);
if (unlikely(ret))
goto fail;
if (PageError(page))
ClearPageError(page);
unlock_page(page);
EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
"outside the limits\n",
inode->i_ino, page->index);
return 0;
}
}
try_again:
if (unlikely(pcol->pg_first == -1)) {
pcol->pg_first = page->index;
} else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
page->index)) {
/* Discontinuity detected, split the request */
ret = write_exec(pcol);
if (unlikely(ret))
goto fail;
EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
inode->i_ino, page->index);
goto try_again;
}
if (!pcol->pages) {
ret = pcol_try_alloc(pcol);
if (unlikely(ret))
goto fail;
}
EXOFS_DBGMSG2(" writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
inode->i_ino, page->index, len);
ret = pcol_add_page(pcol, page, len);
if (unlikely(ret)) {
EXOFS_DBGMSG2("Failed pcol_add_page "
"nr_pages=%u total_length=0x%lx\n",
pcol->nr_pages, pcol->length);
/* split the request, next loop will start again */
ret = write_exec(pcol);
if (unlikely(ret)) {
EXOFS_DBGMSG("write_exec failed => %d", ret);
goto fail;
}
goto try_again;
}
BUG_ON(PageWriteback(page));
set_page_writeback(page);
return 0;
fail:
EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
inode->i_ino, page->index, ret);
mapping_set_error(page->mapping, -EIO);
unlock_page(page);
return ret;
}
static int exofs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct page_collect pcol;
long start, end, expected_pages;
int ret;
start = wbc->range_start >> PAGE_SHIFT;
end = (wbc->range_end == LLONG_MAX) ?
start + mapping->nrpages :
wbc->range_end >> PAGE_SHIFT;
if (start || end)
expected_pages = end - start + 1;
else
expected_pages = mapping->nrpages;
if (expected_pages < 32L)
expected_pages = 32L;
EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
"nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
mapping->host->i_ino, wbc->range_start, wbc->range_end,
mapping->nrpages, start, end, expected_pages);
_pcol_init(&pcol, expected_pages, mapping->host);
ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
if (unlikely(ret)) {
EXOFS_ERR("write_cache_pages => %d\n", ret);
return ret;
}
ret = write_exec(&pcol);
if (unlikely(ret))
return ret;
if (wbc->sync_mode == WB_SYNC_ALL) {
return write_exec(&pcol); /* pump the last reminder */
} else if (pcol.nr_pages) {
/* not SYNC let the reminder join the next writeout */
unsigned i;
for (i = 0; i < pcol.nr_pages; i++) {
struct page *page = pcol.pages[i];
end_page_writeback(page);
set_page_dirty(page);
unlock_page(page);
}
}
return 0;
}
/*
static int exofs_writepage(struct page *page, struct writeback_control *wbc)
{
struct page_collect pcol;
int ret;
_pcol_init(&pcol, 1, page->mapping->host);
ret = writepage_strip(page, NULL, &pcol);
if (ret) {
EXOFS_ERR("exofs_writepage => %d\n", ret);
return ret;
}
return write_exec(&pcol);
}
*/
/* i_mutex held using inode->i_size directly */
static void _write_failed(struct inode *inode, loff_t to)
{
if (to > inode->i_size)
truncate_pagecache(inode, inode->i_size);
}
int exofs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret = 0;
struct page *page;
page = *pagep;
if (page == NULL) {
page = grab_cache_page_write_begin(mapping, pos >> PAGE_SHIFT,
flags);
if (!page) {
EXOFS_DBGMSG("grab_cache_page_write_begin failed\n");
return -ENOMEM;
}
*pagep = page;
}
/* read modify write */
if (!PageUptodate(page) && (len != PAGE_SIZE)) {
loff_t i_size = i_size_read(mapping->host);
pgoff_t end_index = i_size >> PAGE_SHIFT;
if (page->index > end_index) {
clear_highpage(page);
SetPageUptodate(page);
} else {
ret = _readpage(page, true);
if (ret) {
unlock_page(page);
EXOFS_DBGMSG("__readpage failed\n");
}
}
}
return ret;
}
static int exofs_write_begin_export(struct file *file,
struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
*pagep = NULL;
return exofs_write_begin(file, mapping, pos, len, flags, pagep,
fsdata);
}
static int exofs_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
struct inode *inode = mapping->host;
loff_t last_pos = pos + copied;
if (!PageUptodate(page)) {
if (copied < len) {
_write_failed(inode, pos + len);
copied = 0;
goto out;
}
SetPageUptodate(page);
}
if (last_pos > inode->i_size) {
i_size_write(inode, last_pos);
mark_inode_dirty(inode);
}
set_page_dirty(page);
out:
unlock_page(page);
put_page(page);
return copied;
}
static int exofs_releasepage(struct page *page, gfp_t gfp)
{
EXOFS_DBGMSG("page 0x%lx\n", page->index);
WARN_ON(1);
return 0;
}
static void exofs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
EXOFS_DBGMSG("page 0x%lx offset 0x%x length 0x%x\n",
page->index, offset, length);
WARN_ON(1);
}
/* TODO: Should be easy enough to do proprly */
static ssize_t exofs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
return 0;
}
const struct address_space_operations exofs_aops = {
.readpage = exofs_readpage,
.readpages = exofs_readpages,
.writepage = NULL,
.writepages = exofs_writepages,
.write_begin = exofs_write_begin_export,
.write_end = exofs_write_end,
.releasepage = exofs_releasepage,
.set_page_dirty = __set_page_dirty_nobuffers,
.invalidatepage = exofs_invalidatepage,
/* Not implemented Yet */
.bmap = NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
.direct_IO = exofs_direct_IO,
/* With these NULL has special meaning or default is not exported */
.migratepage = NULL,
.launder_page = NULL,
.is_partially_uptodate = NULL,
.error_remove_page = NULL,
};
/******************************************************************************
* INODE OPERATIONS
*****************************************************************************/
/*
* Test whether an inode is a fast symlink.
*/
static inline int exofs_inode_is_fast_symlink(struct inode *inode)
{
struct exofs_i_info *oi = exofs_i(inode);
return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
}
static int _do_truncate(struct inode *inode, loff_t newsize)
{
struct exofs_i_info *oi = exofs_i(inode);
struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
int ret;