linux/fs/exofs/inode.c

846 lines
20 KiB
C
Raw Normal View History

/*
* Copyright (C) 2005, 2006
* Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
* Copyright (C) 2005, 2006
* International Business Machines
* 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/writeback.h>
#include <linux/buffer_head.h>
#include <scsi/scsi_device.h>
#include "exofs.h"
#ifdef CONFIG_EXOFS_DEBUG
# define EXOFS_DEBUG_OBJ_ISIZE 1
#endif
struct page_collect {
struct exofs_sb_info *sbi;
struct request_queue *req_q;
struct inode *inode;
unsigned expected_pages;
struct bio *bio;
unsigned nr_pages;
unsigned long length;
loff_t pg_first; /* keep 64bit also in 32-arches */
};
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;
struct request_queue *req_q = sbi->s_dev->scsi_device->request_queue;
pcol->sbi = sbi;
pcol->req_q = req_q;
pcol->inode = inode;
pcol->expected_pages = expected_pages;
pcol->bio = NULL;
pcol->nr_pages = 0;
pcol->length = 0;
pcol->pg_first = -1;
EXOFS_DBGMSG("_pcol_init ino=0x%lx expected_pages=%u\n", inode->i_ino,
expected_pages);
}
static void _pcol_reset(struct page_collect *pcol)
{
pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
pcol->bio = NULL;
pcol->nr_pages = 0;
pcol->length = 0;
pcol->pg_first = -1;
EXOFS_DBGMSG("_pcol_reset ino=0x%lx expected_pages=%u\n",
pcol->inode->i_ino, pcol->expected_pages);
/* 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 = 128;
}
static int pcol_try_alloc(struct page_collect *pcol)
{
int pages = min_t(unsigned, pcol->expected_pages, BIO_MAX_PAGES);
for (; pages; pages >>= 1) {
pcol->bio = bio_alloc(GFP_KERNEL, pages);
if (likely(pcol->bio))
return 0;
}
EXOFS_ERR("Failed to kcalloc expected_pages=%u\n",
pcol->expected_pages);
return -ENOMEM;
}
static void pcol_free(struct page_collect *pcol)
{
bio_put(pcol->bio);
pcol->bio = NULL;
}
static int pcol_add_page(struct page_collect *pcol, struct page *page,
unsigned len)
{
int added_len = bio_add_pc_page(pcol->req_q, pcol->bio, page, len, 0);
if (unlikely(len != added_len))
return -ENOMEM;
++pcol->nr_pages;
pcol->length += len;
return 0;
}
static int update_read_page(struct page *page, int ret)
{
if (ret == 0) {
/* Everything is OK */
SetPageUptodate(page);
if (PageError(page))
ClearPageError(page);
} else if (ret == -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);
ret = 0; /* recovered error */
EXOFS_DBGMSG("recovered read error\n");
} else /* Error */
SetPageError(page);
return ret;
}
static void update_write_page(struct page *page, int ret)
{
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 osd_request *or, struct page_collect *pcol,
bool do_unlock)
{
struct bio_vec *bvec;
int i;
u64 resid;
u64 good_bytes;
u64 length = 0;
int ret = exofs_check_ok_resid(or, &resid, NULL);
osd_end_request(or);
if (likely(!ret))
good_bytes = pcol->length;
else if (!resid)
good_bytes = 0;
else
good_bytes = pcol->length - resid;
EXOFS_DBGMSG("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);
__bio_for_each_segment(bvec, pcol->bio, i, 0) {
struct page *page = bvec->bv_page;
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_DBGMSG(" 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 (do_unlock)
unlock_page(page);
length += bvec->bv_len;
}
pcol_free(pcol);
EXOFS_DBGMSG("readpages_done END\n");
return ret;
}
/* callback of async reads */
static void readpages_done(struct osd_request *or, void *p)
{
struct page_collect *pcol = p;
__readpages_done(or, pcol, true);
atomic_dec(&pcol->sbi->s_curr_pending);
kfree(p);
}
static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
{
struct bio_vec *bvec;
int i;
__bio_for_each_segment(bvec, pcol->bio, i, 0) {
struct page *page = bvec->bv_page;
if (rw == READ)
update_read_page(page, ret);
else
update_write_page(page, ret);
unlock_page(page);
}
pcol_free(pcol);
}
static int read_exec(struct page_collect *pcol, bool is_sync)
{
struct exofs_i_info *oi = exofs_i(pcol->inode);
struct osd_obj_id obj = {pcol->sbi->s_pid,
pcol->inode->i_ino + EXOFS_OBJ_OFF};
struct osd_request *or = NULL;
struct page_collect *pcol_copy = NULL;
loff_t i_start = pcol->pg_first << PAGE_CACHE_SHIFT;
int ret;
if (!pcol->bio)
return 0;
/* see comment in _readpage() about sync reads */
WARN_ON(is_sync && (pcol->nr_pages != 1));
or = osd_start_request(pcol->sbi->s_dev, GFP_KERNEL);
if (unlikely(!or)) {
ret = -ENOMEM;
goto err;
}
osd_req_read(or, &obj, pcol->bio, i_start);
if (is_sync) {
exofs_sync_op(or, pcol->sbi->s_timeout, oi->i_cred);
return __readpages_done(or, pcol, false);
}
pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
if (!pcol_copy) {
ret = -ENOMEM;
goto err;
}
*pcol_copy = *pcol;
ret = exofs_async_op(or, readpages_done, pcol_copy, oi->i_cred);
if (unlikely(ret))
goto err;
atomic_inc(&pcol->sbi->s_curr_pending);
EXOFS_DBGMSG("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
obj.id, _LLU(i_start), pcol->length);
/* pages ownership was passed to pcol_copy */
_pcol_reset(pcol);
return 0;
err:
if (!is_sync)
_unlock_pcol_pages(pcol, ret, READ);
kfree(pcol_copy);
if (or)
osd_end_request(or);
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);
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);
unlock_page(page);
EXOFS_DBGMSG("readpage_strip(0x%lx, 0x%lx) empty page,"
" splitting\n", inode->i_ino, page->index);
return read_exec(pcol, false);
}
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, false);
if (unlikely(ret))
goto fail;
goto try_again;
}
if (!pcol->bio) {
ret = pcol_try_alloc(pcol);
if (unlikely(ret))
goto fail;
}
if (len != PAGE_CACHE_SIZE)
zero_user(page, len, PAGE_CACHE_SIZE - len);
EXOFS_DBGMSG(" 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_DBGMSG("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, false);
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;
}
return read_exec(&pcol, false);
}
static int _readpage(struct page *page, bool is_sync)
{
struct page_collect pcol;
int ret;
_pcol_init(&pcol, 1, page->mapping->host);
/* readpage_strip might call read_exec(,async) inside at several places
* but this is safe for is_async=0 since read_exec will not do anything
* when we have a single page.
*/
ret = readpage_strip(&pcol, page);
if (ret) {
EXOFS_ERR("_readpage => %d\n", ret);
return ret;
}
return read_exec(&pcol, is_sync);
}
/*
* 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 asynchronouse */
static void writepages_done(struct osd_request *or, void *p)
{
struct page_collect *pcol = p;
struct bio_vec *bvec;
int i;
u64 resid;
u64 good_bytes;
u64 length = 0;
int ret = exofs_check_ok_resid(or, NULL, &resid);
osd_end_request(or);
atomic_dec(&pcol->sbi->s_curr_pending);
if (likely(!ret))
good_bytes = pcol->length;
else if (!resid)
good_bytes = 0;
else
good_bytes = pcol->length - resid;
EXOFS_DBGMSG("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);
__bio_for_each_segment(bvec, pcol->bio, i, 0) {
struct page *page = bvec->bv_page;
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_DBGMSG(" writepages_done(0x%lx, 0x%lx) status=%d\n",
inode->i_ino, page->index, page_stat);
length += bvec->bv_len;
}
pcol_free(pcol);
kfree(pcol);
EXOFS_DBGMSG("writepages_done END\n");
}
static int write_exec(struct page_collect *pcol)
{
struct exofs_i_info *oi = exofs_i(pcol->inode);
struct osd_obj_id obj = {pcol->sbi->s_pid,
pcol->inode->i_ino + EXOFS_OBJ_OFF};
struct osd_request *or = NULL;
struct page_collect *pcol_copy = NULL;
loff_t i_start = pcol->pg_first << PAGE_CACHE_SHIFT;
int ret;
if (!pcol->bio)
return 0;
or = osd_start_request(pcol->sbi->s_dev, GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("write_exec: Faild to osd_start_request()\n");
ret = -ENOMEM;
goto err;
}
pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
if (!pcol_copy) {
EXOFS_ERR("write_exec: Faild to kmalloc(pcol)\n");
ret = -ENOMEM;
goto err;
}
*pcol_copy = *pcol;
osd_req_write(or, &obj, pcol_copy->bio, i_start);
ret = exofs_async_op(or, writepages_done, pcol_copy, oi->i_cred);
if (unlikely(ret)) {
EXOFS_ERR("write_exec: exofs_async_op() Faild\n");
goto err;
}
atomic_inc(&pcol->sbi->s_curr_pending);
EXOFS_DBGMSG("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
pcol->inode->i_ino, pcol->pg_first, _LLU(i_start),
pcol->length);
/* pages ownership was passed to pcol_copy */
_pcol_reset(pcol);
return 0;
err:
_unlock_pcol_pages(pcol, ret, WRITE);
kfree(pcol_copy);
if (or)
osd_end_request(or);
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);
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;
goto try_again;
}
if (!pcol->bio) {
ret = pcol_try_alloc(pcol);
if (unlikely(ret))
goto fail;
}
EXOFS_DBGMSG(" 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_DBGMSG("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 faild => %d", ret);
goto fail;
}
goto try_again;
}
BUG_ON(PageWriteback(page));
set_page_writeback(page);
return 0;
fail:
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 = min(end - start + 1, 32L);
else
expected_pages = mapping->nrpages;
EXOFS_DBGMSG("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx"
" m->nrpages=%lu start=0x%lx end=0x%lx\n",
mapping->host->i_ino, wbc->range_start, wbc->range_end,
mapping->nrpages, start, end);
_pcol_init(&pcol, expected_pages, mapping->host);
ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
if (ret) {
EXOFS_ERR("write_cache_pages => %d\n", ret);
return ret;
}
return write_exec(&pcol);
}
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);
}
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 faild\n");
return ret;
}
page = *pagep;
}
/* read modify write */
if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
ret = _readpage(page, true);
if (ret) {
/*SetPageError was done by _readpage. Is it ok?*/
unlock_page(page);
EXOFS_DBGMSG("__readpage_filler faild\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);
}
const struct address_space_operations exofs_aops = {
.readpage = exofs_readpage,
.readpages = exofs_readpages,
.writepage = exofs_writepage,
.writepages = exofs_writepages,
.write_begin = exofs_write_begin_export,
.write_end = simple_write_end,
};
/******************************************************************************
* 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);
}
/*
* get_block_t - Fill in a buffer_head
* An OSD takes care of block allocation so we just fake an allocation by
* putting in the inode's sector_t in the buffer_head.
* TODO: What about the case of create==0 and @iblock does not exist in the
* object?
*/
static int exofs_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
map_bh(bh_result, inode->i_sb, iblock);
return 0;
}
const struct osd_attr g_attr_logical_length = ATTR_DEF(
OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
/*
* Truncate a file to the specified size - all we have to do is set the size
* attribute. We make sure the object exists first.
*/
void exofs_truncate(struct inode *inode)
{
struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
struct exofs_i_info *oi = exofs_i(inode);
struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
struct osd_request *or;
struct osd_attr attr;
loff_t isize = i_size_read(inode);
__be64 newsize;
int ret;
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
|| S_ISLNK(inode->i_mode)))
return;
if (exofs_inode_is_fast_symlink(inode))
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
nobh_truncate_page(inode->i_mapping, isize, exofs_get_block);
or = osd_start_request(sbi->s_dev, GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("ERROR: exofs_truncate: osd_start_request failed\n");
goto fail;
}
osd_req_set_attributes(or, &obj);
newsize = cpu_to_be64((u64)isize);
attr = g_attr_logical_length;
attr.val_ptr = &newsize;
osd_req_add_set_attr_list(or, &attr, 1);
/* if we are about to truncate an object, and it hasn't been
* created yet, wait
*/
if (unlikely(wait_obj_created(oi)))
goto fail;
ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
osd_end_request(or);
if (ret)
goto fail;
out:
mark_inode_dirty(inode);
return;
fail:
make_bad_inode(inode);
goto out;
}
/*
* Set inode attributes - just call generic functions.
*/
int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = dentry->d_inode;
int error;
error = inode_change_ok(inode, iattr);
if (error)
return error;
error = inode_setattr(inode, iattr);
return error;
}