/* * 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 * * 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 #include #include #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; }