linux/fs/exofs/inode.c
Lukas Czerner d47992f86b mm: change invalidatepage prototype to accept length
Currently there is no way to truncate partial page where the end
truncate point is not at the end of the page. This is because it was not
needed and the functionality was enough for file system truncate
operation to work properly. However more file systems now support punch
hole feature and it can benefit from mm supporting truncating page just
up to the certain point.

Specifically, with this functionality truncate_inode_pages_range() can
be changed so it supports truncating partial page at the end of the
range (currently it will BUG_ON() if 'end' is not at the end of the
page).

This commit changes the invalidatepage() address space operation
prototype to accept range to be invalidated and update all the instances
for it.

We also change the block_invalidatepage() in the same way and actually
make a use of the new length argument implementing range invalidation.

Actual file system implementations will follow except the file systems
where the changes are really simple and should not change the behaviour
in any way .Implementation for truncate_page_range() which will be able
to accept page unaligned ranges will follow as well.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
2013-05-21 23:17:23 -04:00

1521 lines
37 KiB
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)
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(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_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_CACHE_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_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;
loff_t i_size = i_size_read(pcol->inode);
if (offset >= i_size) {
*uptodate = true;
EXOFS_DBGMSG("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);
}
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) && (ZERO_PAGE(0) != page)) {
EXOFS_DBGMSG("index=0x%lx\n", page->index);
page_cache_release(page);
return;
}
EXOFS_DBGMSG("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_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:
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_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 int offset,
unsigned int length)
{
EXOFS_DBGMSG("page 0x%lx offset 0x%x length 0x%x\n",
page->index, offset, length);
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);
i_uid_write(inode, le32_to_cpu(fcb.i_uid));
i_gid_write(inode, 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(i_uid_read(inode));
fcb->i_gid = cpu_to_le32(i_gid_read(inode));
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;
clear_inode(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:
clear_inode(inode);
}