- 根目录:
- fs
- exofs
- inode.c
/*
* Copyright (C) 2005, 2006
* Avishay Traeger (avishay@gmail.com)
* Copyright (C) 2008, 2009
* Boaz Harrosh <bharrosh@panasas.com>
*
* Copyrights for code taken from ext2:
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* 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)
enum {MAX_PAGES_KMALLOC = PAGE_SIZE / sizeof(struct page *), };
unsigned exofs_max_io_pages(struct ore_layout *layout,
unsigned expected_pages)
{
unsigned pages = min_t(unsigned, expected_pages, MAX_PAGES_KMALLOC);
/* TODO: easily support bio chaining */
pages = min_t(unsigned, 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 = MAX_PAGES_KMALLOC;
}
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(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_CACHE_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->read_4_write)
_unlock_pcol_pages(pcol, ret, READ);
pcol_free(pcol);
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_CACHE_SHIFT;
size_t len;
int ret;
/* 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_CACHE_SIZE;
else if (page->index == end_index)
len = i_size & ~PAGE_CACHE_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_CACHE_SIZE)
zero_user(page, len, PAGE_CACHE_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 = 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);
}
if (PageDirty(page) || PageWriteback(page))
*uptodate = true;
else
*uptodate = PageUptodate(page);
EXOFS_DBGMSG("index=0x%lx uptodate=%d\n", index, *uptodate);
return page;
} else {
EXOFS_DBGMSG("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) {
EXOFS_DBGMSG("index=0x%lx\n", page->index);
page_cache_release(page);
return;
}
EXOFS_DBGMSG("that_locked_page index=0x%lx\n", 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_CACHE_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:
_unlock_pcol_pages(pcol, ret, WRITE);
pcol_free(pcol);
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_CACHE_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_CACHE_SIZE;
else {
len = i_size & ~PAGE_CACHE_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);
set_bit(AS_EIO, &page->mapping->flags);
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_CACHE_SHIFT;
end = (wbc->range_end == LLONG_MAX) ?
start + mapping->nrpages :
wbc->range_end >> PAGE_CACHE_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, to, 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) {
ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
fsdata);
if (ret) {
EXOFS_DBGMSG("simple_write_begin failed\n");
goto out;
}
page = *pagep;
}
/* read modify write */
if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
loff_t i_size = i_size_read(mapping->host);
pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
size_t rlen;
if (page->index < end_index)
rlen = PAGE_CACHE_SIZE;
else if (page->index == end_index)
rlen = i_size & ~PAGE_CACHE_MASK;
else
rlen = 0;
if (!rlen) {
clear_highpage(page);
SetPageUptodate(page);
goto out;
}
ret = _readpage(page, true);
if (ret) {
/*SetPageError was done by _readpage. Is it ok?*/
unlock_page(page);
EXOFS_DBGMSG("__readpage failed\n");
}
}
out:
if (unlikely(ret))
_write_failed(mapping->host, pos + len);
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;
/* According to comment in simple_write_end i_mutex is held */
loff_t i_size = inode->i_size;
int ret;
ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
if (unlikely(ret))
_write_failed(inode, pos + len);
/* TODO: once simple_write_end marks inode dirty remove */
if (i_size != inode->i_size)
mark_inode_dirty(inode);
return ret;
}
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 long offset)
{
EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
WARN_ON(1);
}
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 = NULL, /* TODO: Should be trivial to do */
/* With these NULL has special meaning or default is not exported */
.get_xip_mem = NULL,
.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;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
ret = ore_truncate(&sbi->layout, &oi->oc, (u64)newsize);
if (likely(!ret))
truncate_setsize(inode, newsize);
EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
inode->i_ino, newsize, ret);
return ret;
}
/*
* Set inode attributes - update size attribute on OSD if needed,
* otherwise just call generic functions.
*/
int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = dentry->d_inode;
int error;
/* if we are about to modify an object, and it hasn't been
* created yet, wait
*/
error = wait_obj_created(exofs_i(inode));
if (unlikely(error))
return error;
error = inode_change_ok(inode, iattr);
if (unlikely(error))
return error;
if ((iattr->ia_valid & ATTR_SIZE) &&
iattr->ia_size != i_size_read(inode)) {
error = _do_truncate(inode, iattr->ia_size);
if (unlikely(error))
return error;
}
setattr_copy(inode, iattr);
mark_inode_dirty(inode);
return 0;
}
static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
EXOFS_APAGE_FS_DATA,
EXOFS_ATTR_INODE_FILE_LAYOUT,
0);
static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
EXOFS_APAGE_FS_DATA,
EXOFS_ATTR_INODE_DIR_LAYOUT,
0);
/*
* Read the Linux inode info from the OSD, and return it as is. In exofs the
* inode info is in an application specific page/attribute of the osd-object.
*/
static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
struct exofs_fcb *inode)
{
struct exofs_sb_info *sbi = sb->s_fs_info;
struct osd_attr attrs[] = {
[0] = g_attr_inode_data,
[1] = g_attr_inode_file_layout,
[2] = g_attr_inode_dir_layout,
};
struct ore_io_state *ios;
struct exofs_on_disk_inode_layout *layout;
int ret;
ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
if (unlikely(ret)) {
EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
return ret;
}
attrs[1].len = exofs_on_disk_inode_layout_size(sbi->oc.numdevs);
attrs[2].len = exofs_on_disk_inode_layout_size(sbi->oc.numdevs);
ios->in_attr = attrs;
ios->in_attr_len = ARRAY_SIZE(attrs);
ret = ore_read(ios);
if (unlikely(ret)) {
EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
_LLU(oi->one_comp.obj.id), ret);
memset(inode, 0, sizeof(*inode));
inode->i_mode = 0040000 | (0777 & ~022);
/* If object is lost on target we might as well enable it's
* delete.
*/
if ((ret == -ENOENT) || (ret == -EINVAL))
ret = 0;
goto out;
}
ret = extract_attr_from_ios(ios, &attrs[0]);
if (ret) {
EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
goto out;
}
WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
ret = extract_attr_from_ios(ios, &attrs[1]);
if (ret) {
EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
goto out;
}
if (attrs[1].len) {
layout = attrs[1].val_ptr;
if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
EXOFS_ERR("%s: unsupported files layout %d\n",
__func__, layout->gen_func);
ret = -ENOTSUPP;
goto out;
}
}
ret = extract_attr_from_ios(ios, &attrs[2]);
if (ret) {
EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
goto out;
}
if (attrs[2].len) {
layout = attrs[2].val_ptr;
if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
EXOFS_ERR("%s: unsupported meta-data layout %d\n",
__func__, layout->gen_func);
ret = -ENOTSUPP;
goto out;
}
}
out:
ore_put_io_state(ios);
return ret;
}
static void __oi_init(struct exofs_i_info *oi)
{
init_waitqueue_head(&oi->i_wq);
oi->i_flags = 0;
}
/*
* Fill in an inode read from the OSD and set it up for use
*/
struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
{
struct exofs_i_info *oi;
struct exofs_fcb fcb;
struct inode *inode;
int ret;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
oi = exofs_i(inode);
__oi_init(oi);
exofs_init_comps(&oi->oc, &oi->one_comp, sb->s_fs_info,
exofs_oi_objno(oi));
/* read the inode from the osd */
ret = exofs_get_inode(sb, oi, &fcb);
if (ret)
goto bad_inode;
set_obj_created(oi);
/* copy stuff from on-disk struct to in-memory struct */
inode->i_mode = le16_to_cpu(fcb.i_mode);
inode->i_uid = le32_to_cpu(fcb.i_uid);
inode->i_gid = le32_to_cpu(fcb.i_gid);
set_nlink(inode, le16_to_cpu(fcb.i_links_count));
inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
inode->i_ctime.tv_nsec =
inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
oi->i_commit_size = le64_to_cpu(fcb.i_size);
i_size_write(inode, oi->i_commit_size);
inode->i_blkbits = EXOFS_BLKSHIFT;
inode->i_generation = le32_to_cpu(fcb.i_generation);
oi->i_dir_start_lookup = 0;
if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
ret = -ESTALE;
goto bad_inode;
}
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
if (fcb.i_data[0])
inode->i_rdev =
old_decode_dev(le32_to_cpu(fcb.i_data[0]));
else
inode->i_rdev =
new_decode_dev(le32_to_cpu(fcb.i_data[1]));
} else {
memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
}
inode->i_mapping->backing_dev_info = sb->s_bdi;
if (S_ISREG(inode->i_mode)) {
inode->i_op = &exofs_file_inode_operations;
inode->i_fop = &exofs_file_operations;
inode->i_mapping->a_ops = &exofs_aops;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &exofs_dir_inode_operations;
inode->i_fop = &exofs_dir_operations;
inode->i_mapping->a_ops = &exofs_aops;
} else if (S_ISLNK(inode->i_mode)) {
if (exofs_inode_is_fast_symlink(inode))
inode->i_op = &exofs_fast_symlink_inode_operations;
else {
inode->i_op = &exofs_symlink_inode_operations;
inode->i_mapping->a_ops = &exofs_aops;
}
} else {
inode->i_op = &exofs_special_inode_operations;
if (fcb.i_data[0])
init_special_inode(inode, inode->i_mode,
old_decode_dev(le32_to_cpu(fcb.i_data[0])));
else
init_special_inode(inode, inode->i_mode,
new_decode_dev(le32_to_cpu(fcb.i_data[1])));
}
unlock_new_inode(inode);
return inode;
bad_inode:
iget_failed(inode);
return ERR_PTR(ret);
}
int __exofs_wait_obj_created(struct exofs_i_info *oi)
{
if (!obj_created(oi)) {
EXOFS_DBGMSG("!obj_created\n");
BUG_ON(!obj_2bcreated(oi));
wait_event(oi->i_wq, obj_created(oi));
EXOFS_DBGMSG("wait_event done\n");
}
return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
}
/*
* Callback function from exofs_new_inode(). The important thing is that we
* set the obj_created flag so that other methods know that the object exists on
* the OSD.
*/
static void create_done(struct ore_io_state *ios, void *p)
{
struct inode *inode = p;
struct exofs_i_info *oi = exofs_i(inode);
struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
int ret;
ret = ore_check_io(ios, NULL);
ore_put_io_state(ios);
atomic_dec(&sbi->s_curr_pending);
if (unlikely(ret)) {
EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
_LLU(exofs_oi_objno(oi)),
_LLU(oi->one_comp.obj.partition));
/*TODO: When FS is corrupted creation can fail, object already
* exist. Get rid of this asynchronous creation, if exist
* increment the obj counter and try the next object. Until we
* succeed. All these dangling objects will be made into lost
* files by chkfs.exofs
*/
}
set_obj_created(oi);
wake_up(&oi->i_wq);
}
/*
* Set up a new inode and create an object for it on the OSD
*/
struct inode *exofs_new_inode(struct inode *dir, umode_t mode)
{
struct super_block *sb = dir->i_sb;
struct exofs_sb_info *sbi = sb->s_fs_info;
struct inode *inode;
struct exofs_i_info *oi;
struct ore_io_state *ios;
int ret;
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
oi = exofs_i(inode);
__oi_init(oi);
set_obj_2bcreated(oi);
inode->i_mapping->backing_dev_info = sb->s_bdi;
inode_init_owner(inode, dir, mode);
inode->i_ino = sbi->s_nextid++;
inode->i_blkbits = EXOFS_BLKSHIFT;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
oi->i_commit_size = inode->i_size = 0;
spin_lock(&sbi->s_next_gen_lock);
inode->i_generation = sbi->s_next_generation++;
spin_unlock(&sbi->s_next_gen_lock);
insert_inode_hash(inode);
exofs_init_comps(&oi->oc, &oi->one_comp, sb->s_fs_info,
exofs_oi_objno(oi));
exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
mark_inode_dirty(inode);
ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
if (unlikely(ret)) {
EXOFS_ERR("exofs_new_inode: ore_get_io_state failed\n");
return ERR_PTR(ret);
}
ios->done = create_done;
ios->private = inode;
ret = ore_create(ios);
if (ret) {
ore_put_io_state(ios);
return ERR_PTR(ret);
}
atomic_inc(&sbi->s_curr_pending);
return inode;
}
/*
* struct to pass two arguments to update_inode's callback
*/
struct updatei_args {
struct exofs_sb_info *sbi;
struct exofs_fcb fcb;
};
/*
* Callback function from exofs_update_inode().
*/
static void updatei_done(struct ore_io_state *ios, void *p)
{
struct updatei_args *args = p;
ore_put_io_state(ios);
atomic_dec(&args->sbi->s_curr_pending);
kfree(args);
}
/*
* Write the inode to the OSD. Just fill up the struct, and set the attribute
* synchronously or asynchronously depending on the do_sync flag.
*/
static int exofs_update_inode(struct inode *inode, int do_sync)
{
struct exofs_i_info *oi = exofs_i(inode);
struct super_block *sb = inode->i_sb;
struct exofs_sb_info *sbi = sb->s_fs_info;
struct ore_io_state *ios;
struct osd_attr attr;
struct exofs_fcb *fcb;
struct updatei_args *args;
int ret;
args = kzalloc(sizeof(*args), GFP_KERNEL);
if (!args) {
EXOFS_DBGMSG("Failed kzalloc of args\n");
return -ENOMEM;
}
fcb = &args->fcb;
fcb->i_mode = cpu_to_le16(inode->i_mode);
fcb->i_uid = cpu_to_le32(inode->i_uid);
fcb->i_gid = cpu_to_le32(inode->i_gid);
fcb->i_links_count = cpu_to_le16(inode->i_nlink);
fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
oi->i_commit_size = i_size_read(inode);
fcb->i_size = cpu_to_le64(oi->i_commit_size);
fcb->i_generation = cpu_to_le32(inode->i_generation);
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
if (old_valid_dev(inode->i_rdev)) {
fcb->i_data[0] =
cpu_to_le32(old_encode_dev(inode->i_rdev));
fcb->i_data[1] = 0;
} else {
fcb->i_data[0] = 0;
fcb->i_data[1] =
cpu_to_le32(new_encode_dev(inode->i_rdev));
fcb->i_data[2] = 0;
}
} else
memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
if (unlikely(ret)) {
EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
goto free_args;
}
attr = g_attr_inode_data;
attr.val_ptr = fcb;
ios->out_attr_len = 1;
ios->out_attr = &attr;
wait_obj_created(oi);
if (!do_sync) {
args->sbi = sbi;
ios->done = updatei_done;
ios->private = args;
}
ret = ore_write(ios);
if (!do_sync && !ret) {
atomic_inc(&sbi->s_curr_pending);
goto out; /* deallocation in updatei_done */
}
ore_put_io_state(ios);
free_args:
kfree(args);
out:
EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
inode->i_ino, do_sync, ret);
return ret;
}
int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
/* FIXME: fix fsync and use wbc->sync_mode == WB_SYNC_ALL */
return exofs_update_inode(inode, 1);
}
/*
* Callback function from exofs_delete_inode() - don't have much cleaning up to
* do.
*/
static void delete_done(struct ore_io_state *ios, void *p)
{
struct exofs_sb_info *sbi = p;
ore_put_io_state(ios);
atomic_dec(&sbi->s_curr_pending);
}
/*
* Called when the refcount of an inode reaches zero. We remove the object
* from the OSD here. We make sure the object was created before we try and
* delete it.
*/
void exofs_evict_inode(struct inode *inode)
{
struct exofs_i_info *oi = exofs_i(inode);
struct super_block *sb = inode->i_sb;
struct exofs_sb_info *sbi = sb->s_fs_info;
struct ore_io_state *ios;
int ret;
truncate_inode_pages(&inode->i_data, 0);
/* TODO: should do better here */
if (inode->i_nlink || is_bad_inode(inode))
goto no_delete;
inode->i_size = 0;
end_writeback(inode);
/* if we are deleting an obj that hasn't been created yet, wait.
* This also makes sure that create_done cannot be called with an
* already evicted inode.
*/
wait_obj_created(oi);
/* ignore the error, attempt a remove anyway */
/* Now Remove the OSD objects */
ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
if (unlikely(ret)) {
EXOFS_ERR("%s: ore_get_io_state failed\n", __func__);
return;
}
ios->done = delete_done;
ios->private = sbi;
ret = ore_remove(ios);
if (ret) {
EXOFS_ERR("%s: ore_remove failed\n", __func__);
ore_put_io_state(ios);
return;
}
atomic_inc(&sbi->s_curr_pending);
return;
no_delete:
end_writeback(inode);
}