diff options
Diffstat (limited to 'fs/gfs2/aops.c')
-rw-r--r-- | fs/gfs2/aops.c | 772 |
1 files changed, 772 insertions, 0 deletions
diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c new file mode 100644 index 000000000..1e9fa26f0 --- /dev/null +++ b/fs/gfs2/aops.c @@ -0,0 +1,772 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/pagemap.h> +#include <linux/pagevec.h> +#include <linux/mpage.h> +#include <linux/fs.h> +#include <linux/writeback.h> +#include <linux/swap.h> +#include <linux/gfs2_ondisk.h> +#include <linux/backing-dev.h> +#include <linux/uio.h> +#include <trace/events/writeback.h> +#include <linux/sched/signal.h> + +#include "gfs2.h" +#include "incore.h" +#include "bmap.h" +#include "glock.h" +#include "inode.h" +#include "log.h" +#include "meta_io.h" +#include "quota.h" +#include "trans.h" +#include "rgrp.h" +#include "super.h" +#include "util.h" +#include "glops.h" +#include "aops.h" + + +void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, + unsigned int from, unsigned int len) +{ + struct buffer_head *head = page_buffers(page); + unsigned int bsize = head->b_size; + struct buffer_head *bh; + unsigned int to = from + len; + unsigned int start, end; + + for (bh = head, start = 0; bh != head || !start; + bh = bh->b_this_page, start = end) { + end = start + bsize; + if (end <= from) + continue; + if (start >= to) + break; + set_buffer_uptodate(bh); + gfs2_trans_add_data(ip->i_gl, bh); + } +} + +/** + * gfs2_get_block_noalloc - Fills in a buffer head with details about a block + * @inode: The inode + * @lblock: The block number to look up + * @bh_result: The buffer head to return the result in + * @create: Non-zero if we may add block to the file + * + * Returns: errno + */ + +static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock, + struct buffer_head *bh_result, int create) +{ + int error; + + error = gfs2_block_map(inode, lblock, bh_result, 0); + if (error) + return error; + if (!buffer_mapped(bh_result)) + return -ENODATA; + return 0; +} + +/** + * gfs2_write_jdata_page - gfs2 jdata-specific version of block_write_full_page + * @page: The page to write + * @wbc: The writeback control + * + * This is the same as calling block_write_full_page, but it also + * writes pages outside of i_size + */ +static int gfs2_write_jdata_page(struct page *page, + struct writeback_control *wbc) +{ + struct inode * const inode = page->mapping->host; + loff_t i_size = i_size_read(inode); + const pgoff_t end_index = i_size >> PAGE_SHIFT; + unsigned offset; + + /* + * The page straddles i_size. It must be zeroed out on each and every + * writepage invocation because it may be mmapped. "A file is mapped + * in multiples of the page size. For a file that is not a multiple of + * the page size, the remaining memory is zeroed when mapped, and + * writes to that region are not written out to the file." + */ + offset = i_size & (PAGE_SIZE - 1); + if (page->index == end_index && offset) + zero_user_segment(page, offset, PAGE_SIZE); + + return __block_write_full_page(inode, page, gfs2_get_block_noalloc, wbc, + end_buffer_async_write); +} + +/** + * __gfs2_jdata_writepage - The core of jdata writepage + * @page: The page to write + * @wbc: The writeback control + * + * This is shared between writepage and writepages and implements the + * core of the writepage operation. If a transaction is required then + * PageChecked will have been set and the transaction will have + * already been started before this is called. + */ + +static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) +{ + struct inode *inode = page->mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + + if (PageChecked(page)) { + ClearPageChecked(page); + if (!page_has_buffers(page)) { + create_empty_buffers(page, inode->i_sb->s_blocksize, + BIT(BH_Dirty)|BIT(BH_Uptodate)); + } + gfs2_page_add_databufs(ip, page, 0, PAGE_SIZE); + } + return gfs2_write_jdata_page(page, wbc); +} + +/** + * gfs2_jdata_writepage - Write complete page + * @page: Page to write + * @wbc: The writeback control + * + * Returns: errno + * + */ + +static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc) +{ + struct inode *inode = page->mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + + if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) + goto out; + if (PageChecked(page) || current->journal_info) + goto out_ignore; + return __gfs2_jdata_writepage(page, wbc); + +out_ignore: + redirty_page_for_writepage(wbc, page); +out: + unlock_page(page); + return 0; +} + +/** + * gfs2_writepages - Write a bunch of dirty pages back to disk + * @mapping: The mapping to write + * @wbc: Write-back control + * + * Used for both ordered and writeback modes. + */ +static int gfs2_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); + struct iomap_writepage_ctx wpc = { }; + int ret; + + /* + * Even if we didn't write enough pages here, we might still be holding + * dirty pages in the ail. We forcibly flush the ail because we don't + * want balance_dirty_pages() to loop indefinitely trying to write out + * pages held in the ail that it can't find. + */ + ret = iomap_writepages(mapping, wbc, &wpc, &gfs2_writeback_ops); + if (ret == 0 && wbc->nr_to_write > 0) + set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags); + return ret; +} + +/** + * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages + * @mapping: The mapping + * @wbc: The writeback control + * @pvec: The vector of pages + * @nr_pages: The number of pages to write + * @done_index: Page index + * + * Returns: non-zero if loop should terminate, zero otherwise + */ + +static int gfs2_write_jdata_pagevec(struct address_space *mapping, + struct writeback_control *wbc, + struct pagevec *pvec, + int nr_pages, + pgoff_t *done_index) +{ + struct inode *inode = mapping->host; + struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned nrblocks = nr_pages * (PAGE_SIZE >> inode->i_blkbits); + int i; + int ret; + + ret = gfs2_trans_begin(sdp, nrblocks, nrblocks); + if (ret < 0) + return ret; + + for(i = 0; i < nr_pages; i++) { + struct page *page = pvec->pages[i]; + + *done_index = page->index; + + lock_page(page); + + if (unlikely(page->mapping != mapping)) { +continue_unlock: + unlock_page(page); + continue; + } + + if (!PageDirty(page)) { + /* someone wrote it for us */ + goto continue_unlock; + } + + if (PageWriteback(page)) { + if (wbc->sync_mode != WB_SYNC_NONE) + wait_on_page_writeback(page); + else + goto continue_unlock; + } + + BUG_ON(PageWriteback(page)); + if (!clear_page_dirty_for_io(page)) + goto continue_unlock; + + trace_wbc_writepage(wbc, inode_to_bdi(inode)); + + ret = __gfs2_jdata_writepage(page, wbc); + if (unlikely(ret)) { + if (ret == AOP_WRITEPAGE_ACTIVATE) { + unlock_page(page); + ret = 0; + } else { + + /* + * done_index is set past this page, + * so media errors will not choke + * background writeout for the entire + * file. This has consequences for + * range_cyclic semantics (ie. it may + * not be suitable for data integrity + * writeout). + */ + *done_index = page->index + 1; + ret = 1; + break; + } + } + + /* + * We stop writing back only if we are not doing + * integrity sync. In case of integrity sync we have to + * keep going until we have written all the pages + * we tagged for writeback prior to entering this loop. + */ + if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) { + ret = 1; + break; + } + + } + gfs2_trans_end(sdp); + return ret; +} + +/** + * gfs2_write_cache_jdata - Like write_cache_pages but different + * @mapping: The mapping to write + * @wbc: The writeback control + * + * The reason that we use our own function here is that we need to + * start transactions before we grab page locks. This allows us + * to get the ordering right. + */ + +static int gfs2_write_cache_jdata(struct address_space *mapping, + struct writeback_control *wbc) +{ + int ret = 0; + int done = 0; + struct pagevec pvec; + int nr_pages; + pgoff_t writeback_index; + pgoff_t index; + pgoff_t end; + pgoff_t done_index; + int cycled; + int range_whole = 0; + xa_mark_t tag; + + pagevec_init(&pvec); + if (wbc->range_cyclic) { + writeback_index = mapping->writeback_index; /* prev offset */ + index = writeback_index; + if (index == 0) + cycled = 1; + else + cycled = 0; + end = -1; + } else { + index = wbc->range_start >> PAGE_SHIFT; + end = wbc->range_end >> PAGE_SHIFT; + if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) + range_whole = 1; + cycled = 1; /* ignore range_cyclic tests */ + } + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + tag = PAGECACHE_TAG_TOWRITE; + else + tag = PAGECACHE_TAG_DIRTY; + +retry: + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + tag_pages_for_writeback(mapping, index, end); + done_index = index; + while (!done && (index <= end)) { + nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end, + tag); + if (nr_pages == 0) + break; + + ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index); + if (ret) + done = 1; + if (ret > 0) + ret = 0; + pagevec_release(&pvec); + cond_resched(); + } + + if (!cycled && !done) { + /* + * range_cyclic: + * We hit the last page and there is more work to be done: wrap + * back to the start of the file + */ + cycled = 1; + index = 0; + end = writeback_index - 1; + goto retry; + } + + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) + mapping->writeback_index = done_index; + + return ret; +} + + +/** + * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk + * @mapping: The mapping to write + * @wbc: The writeback control + * + */ + +static int gfs2_jdata_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct gfs2_inode *ip = GFS2_I(mapping->host); + struct gfs2_sbd *sdp = GFS2_SB(mapping->host); + int ret; + + ret = gfs2_write_cache_jdata(mapping, wbc); + if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) { + gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL | + GFS2_LFC_JDATA_WPAGES); + ret = gfs2_write_cache_jdata(mapping, wbc); + } + return ret; +} + +/** + * stuffed_readpage - Fill in a Linux page with stuffed file data + * @ip: the inode + * @page: the page + * + * Returns: errno + */ +static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) +{ + struct buffer_head *dibh; + u64 dsize = i_size_read(&ip->i_inode); + void *kaddr; + int error; + + /* + * Due to the order of unstuffing files and ->fault(), we can be + * asked for a zero page in the case of a stuffed file being extended, + * so we need to supply one here. It doesn't happen often. + */ + if (unlikely(page->index)) { + zero_user(page, 0, PAGE_SIZE); + SetPageUptodate(page); + return 0; + } + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + return error; + + kaddr = kmap_atomic(page); + memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); + memset(kaddr + dsize, 0, PAGE_SIZE - dsize); + kunmap_atomic(kaddr); + flush_dcache_page(page); + brelse(dibh); + SetPageUptodate(page); + + return 0; +} + +/** + * gfs2_read_folio - read a folio from a file + * @file: The file to read + * @folio: The folio in the file + */ +static int gfs2_read_folio(struct file *file, struct folio *folio) +{ + struct inode *inode = folio->mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + int error; + + if (!gfs2_is_jdata(ip) || + (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) { + error = iomap_read_folio(folio, &gfs2_iomap_ops); + } else if (gfs2_is_stuffed(ip)) { + error = stuffed_readpage(ip, &folio->page); + folio_unlock(folio); + } else { + error = mpage_read_folio(folio, gfs2_block_map); + } + + if (unlikely(gfs2_withdrawn(sdp))) + return -EIO; + + return error; +} + +/** + * gfs2_internal_read - read an internal file + * @ip: The gfs2 inode + * @buf: The buffer to fill + * @pos: The file position + * @size: The amount to read + * + */ + +int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos, + unsigned size) +{ + struct address_space *mapping = ip->i_inode.i_mapping; + unsigned long index = *pos >> PAGE_SHIFT; + unsigned offset = *pos & (PAGE_SIZE - 1); + unsigned copied = 0; + unsigned amt; + struct page *page; + void *p; + + do { + amt = size - copied; + if (offset + size > PAGE_SIZE) + amt = PAGE_SIZE - offset; + page = read_cache_page(mapping, index, gfs2_read_folio, NULL); + if (IS_ERR(page)) + return PTR_ERR(page); + p = kmap_atomic(page); + memcpy(buf + copied, p + offset, amt); + kunmap_atomic(p); + put_page(page); + copied += amt; + index++; + offset = 0; + } while(copied < size); + (*pos) += size; + return size; +} + +/** + * gfs2_readahead - Read a bunch of pages at once + * @rac: Read-ahead control structure + * + * Some notes: + * 1. This is only for readahead, so we can simply ignore any things + * which are slightly inconvenient (such as locking conflicts between + * the page lock and the glock) and return having done no I/O. Its + * obviously not something we'd want to do on too regular a basis. + * Any I/O we ignore at this time will be done via readpage later. + * 2. We don't handle stuffed files here we let readpage do the honours. + * 3. mpage_readahead() does most of the heavy lifting in the common case. + * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places. + */ + +static void gfs2_readahead(struct readahead_control *rac) +{ + struct inode *inode = rac->mapping->host; + struct gfs2_inode *ip = GFS2_I(inode); + + if (gfs2_is_stuffed(ip)) + ; + else if (gfs2_is_jdata(ip)) + mpage_readahead(rac, gfs2_block_map); + else + iomap_readahead(rac, &gfs2_iomap_ops); +} + +/** + * adjust_fs_space - Adjusts the free space available due to gfs2_grow + * @inode: the rindex inode + */ +void adjust_fs_space(struct inode *inode) +{ + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); + struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master; + struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; + struct buffer_head *m_bh; + u64 fs_total, new_free; + + if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0) + return; + + /* Total up the file system space, according to the latest rindex. */ + fs_total = gfs2_ri_total(sdp); + if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0) + goto out; + + spin_lock(&sdp->sd_statfs_spin); + gfs2_statfs_change_in(m_sc, m_bh->b_data + + sizeof(struct gfs2_dinode)); + if (fs_total > (m_sc->sc_total + l_sc->sc_total)) + new_free = fs_total - (m_sc->sc_total + l_sc->sc_total); + else + new_free = 0; + spin_unlock(&sdp->sd_statfs_spin); + fs_warn(sdp, "File system extended by %llu blocks.\n", + (unsigned long long)new_free); + gfs2_statfs_change(sdp, new_free, new_free, 0); + + update_statfs(sdp, m_bh); + brelse(m_bh); +out: + sdp->sd_rindex_uptodate = 0; + gfs2_trans_end(sdp); +} + +static bool jdata_dirty_folio(struct address_space *mapping, + struct folio *folio) +{ + if (current->journal_info) + folio_set_checked(folio); + return block_dirty_folio(mapping, folio); +} + +/** + * gfs2_bmap - Block map function + * @mapping: Address space info + * @lblock: The block to map + * + * Returns: The disk address for the block or 0 on hole or error + */ + +static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) +{ + struct gfs2_inode *ip = GFS2_I(mapping->host); + struct gfs2_holder i_gh; + sector_t dblock = 0; + int error; + + error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); + if (error) + return 0; + + if (!gfs2_is_stuffed(ip)) + dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops); + + gfs2_glock_dq_uninit(&i_gh); + + return dblock; +} + +static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh) +{ + struct gfs2_bufdata *bd; + + lock_buffer(bh); + gfs2_log_lock(sdp); + clear_buffer_dirty(bh); + bd = bh->b_private; + if (bd) { + if (!list_empty(&bd->bd_list) && !buffer_pinned(bh)) + list_del_init(&bd->bd_list); + else { + spin_lock(&sdp->sd_ail_lock); + gfs2_remove_from_journal(bh, REMOVE_JDATA); + spin_unlock(&sdp->sd_ail_lock); + } + } + bh->b_bdev = NULL; + clear_buffer_mapped(bh); + clear_buffer_req(bh); + clear_buffer_new(bh); + gfs2_log_unlock(sdp); + unlock_buffer(bh); +} + +static void gfs2_invalidate_folio(struct folio *folio, size_t offset, + size_t length) +{ + struct gfs2_sbd *sdp = GFS2_SB(folio->mapping->host); + size_t stop = offset + length; + int partial_page = (offset || length < folio_size(folio)); + struct buffer_head *bh, *head; + unsigned long pos = 0; + + BUG_ON(!folio_test_locked(folio)); + if (!partial_page) + folio_clear_checked(folio); + head = folio_buffers(folio); + if (!head) + goto out; + + bh = head; + do { + if (pos + bh->b_size > stop) + return; + + if (offset <= pos) + gfs2_discard(sdp, bh); + pos += bh->b_size; + bh = bh->b_this_page; + } while (bh != head); +out: + if (!partial_page) + filemap_release_folio(folio, 0); +} + +/** + * gfs2_release_folio - free the metadata associated with a folio + * @folio: the folio that's being released + * @gfp_mask: passed from Linux VFS, ignored by us + * + * Calls try_to_free_buffers() to free the buffers and put the folio if the + * buffers can be released. + * + * Returns: true if the folio was put or else false + */ + +bool gfs2_release_folio(struct folio *folio, gfp_t gfp_mask) +{ + struct address_space *mapping = folio->mapping; + struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping); + struct buffer_head *bh, *head; + struct gfs2_bufdata *bd; + + head = folio_buffers(folio); + if (!head) + return false; + + /* + * mm accommodates an old ext3 case where clean folios might + * not have had the dirty bit cleared. Thus, it can send actual + * dirty folios to ->release_folio() via shrink_active_list(). + * + * As a workaround, we skip folios that contain dirty buffers + * below. Once ->release_folio isn't called on dirty folios + * anymore, we can warn on dirty buffers like we used to here + * again. + */ + + gfs2_log_lock(sdp); + bh = head; + do { + if (atomic_read(&bh->b_count)) + goto cannot_release; + bd = bh->b_private; + if (bd && bd->bd_tr) + goto cannot_release; + if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh))) + goto cannot_release; + bh = bh->b_this_page; + } while (bh != head); + + bh = head; + do { + bd = bh->b_private; + if (bd) { + gfs2_assert_warn(sdp, bd->bd_bh == bh); + bd->bd_bh = NULL; + bh->b_private = NULL; + /* + * The bd may still be queued as a revoke, in which + * case we must not dequeue nor free it. + */ + if (!bd->bd_blkno && !list_empty(&bd->bd_list)) + list_del_init(&bd->bd_list); + if (list_empty(&bd->bd_list)) + kmem_cache_free(gfs2_bufdata_cachep, bd); + } + + bh = bh->b_this_page; + } while (bh != head); + gfs2_log_unlock(sdp); + + return try_to_free_buffers(folio); + +cannot_release: + gfs2_log_unlock(sdp); + return false; +} + +static const struct address_space_operations gfs2_aops = { + .writepages = gfs2_writepages, + .read_folio = gfs2_read_folio, + .readahead = gfs2_readahead, + .dirty_folio = filemap_dirty_folio, + .release_folio = iomap_release_folio, + .invalidate_folio = iomap_invalidate_folio, + .bmap = gfs2_bmap, + .direct_IO = noop_direct_IO, + .migrate_folio = filemap_migrate_folio, + .is_partially_uptodate = iomap_is_partially_uptodate, + .error_remove_page = generic_error_remove_page, +}; + +static const struct address_space_operations gfs2_jdata_aops = { + .writepage = gfs2_jdata_writepage, + .writepages = gfs2_jdata_writepages, + .read_folio = gfs2_read_folio, + .readahead = gfs2_readahead, + .dirty_folio = jdata_dirty_folio, + .bmap = gfs2_bmap, + .invalidate_folio = gfs2_invalidate_folio, + .release_folio = gfs2_release_folio, + .is_partially_uptodate = block_is_partially_uptodate, + .error_remove_page = generic_error_remove_page, +}; + +void gfs2_set_aops(struct inode *inode) +{ + if (gfs2_is_jdata(GFS2_I(inode))) + inode->i_mapping->a_ops = &gfs2_jdata_aops; + else + inode->i_mapping->a_ops = &gfs2_aops; +} |