| /* |
| * 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; |
| } |