diff options
Diffstat (limited to 'fs/gfs2/ops_address.c')
| -rw-r--r-- | fs/gfs2/ops_address.c | 853 |
1 files changed, 0 insertions, 853 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c deleted file mode 100644 index 9679f8b9870..00000000000 --- a/fs/gfs2/ops_address.c +++ /dev/null @@ -1,853 +0,0 @@ -/* - * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. - * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. - * - * This copyrighted material is made available to anyone wishing to use, - * modify, copy, or redistribute it subject to the terms and conditions - * of the GNU General Public License version 2. - */ - -#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/lm_interface.h> - -#include "gfs2.h" -#include "incore.h" -#include "bmap.h" -#include "glock.h" -#include "inode.h" -#include "log.h" -#include "meta_io.h" -#include "ops_address.h" -#include "quota.h" -#include "trans.h" -#include "rgrp.h" -#include "ops_file.h" -#include "super.h" -#include "util.h" -#include "glops.h" - - -static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, - unsigned int from, unsigned int to) -{ - struct buffer_head *head = page_buffers(page); - unsigned int bsize = head->b_size; - struct buffer_head *bh; - 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 || start >= to) - continue; - if (gfs2_is_jdata(ip)) - set_buffer_uptodate(bh); - gfs2_trans_add_bh(ip->i_gl, bh, 0); - } -} - -/** - * gfs2_get_block - 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 - */ - -int gfs2_get_block(struct inode *inode, sector_t lblock, - struct buffer_head *bh_result, int create) -{ - return gfs2_block_map(inode, lblock, create, bh_result); -} - -/** - * 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, 0, bh_result); - if (error) - return error; - if (!buffer_mapped(bh_result)) - return -EIO; - return 0; -} - -static int gfs2_get_block_direct(struct inode *inode, sector_t lblock, - struct buffer_head *bh_result, int create) -{ - return gfs2_block_map(inode, lblock, 0, bh_result); -} - -/** - * gfs2_writepage - Write complete page - * @page: Page to write - * - * Returns: errno - * - * Some of this is copied from block_write_full_page() although we still - * call it to do most of the work. - */ - -static int gfs2_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); - loff_t i_size = i_size_read(inode); - pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; - unsigned offset; - int error; - int done_trans = 0; - - if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) { - unlock_page(page); - return -EIO; - } - if (current->journal_info) - goto out_ignore; - - /* Is the page fully outside i_size? (truncate in progress) */ - offset = i_size & (PAGE_CACHE_SIZE-1); - if (page->index > end_index || (page->index == end_index && !offset)) { - page->mapping->a_ops->invalidatepage(page, 0); - unlock_page(page); - return 0; /* don't care */ - } - - if ((sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) && - PageChecked(page)) { - ClearPageChecked(page); - error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); - if (error) - goto out_ignore; - if (!page_has_buffers(page)) { - create_empty_buffers(page, inode->i_sb->s_blocksize, - (1 << BH_Dirty)|(1 << BH_Uptodate)); - } - gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); - done_trans = 1; - } - error = block_write_full_page(page, gfs2_get_block_noalloc, wbc); - if (done_trans) - gfs2_trans_end(sdp); - gfs2_meta_cache_flush(ip); - return error; - -out_ignore: - redirty_page_for_writepage(wbc, page); - 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 - * - * For journaled files and/or ordered writes this just falls back to the - * kernel's default writepages path for now. We will probably want to change - * that eventually (i.e. when we look at allocate on flush). - * - * For the data=writeback case though we can already ignore buffer heads - * and write whole extents at once. This is a big reduction in the - * number of I/O requests we send and the bmap calls we make in this case. - */ -static int gfs2_writepages(struct address_space *mapping, - struct writeback_control *wbc) -{ - struct inode *inode = mapping->host; - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_sbd *sdp = GFS2_SB(inode); - - if (sdp->sd_args.ar_data == GFS2_DATA_WRITEBACK && !gfs2_is_jdata(ip)) - return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc); - - return generic_writepages(mapping, wbc); -} - -/** - * 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; - void *kaddr; - int error; - - /* - * Due to the order of unstuffing files and ->nopage(), 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(page, 0, PAGE_CACHE_SIZE, KM_USER0); - return 0; - } - - error = gfs2_meta_inode_buffer(ip, &dibh); - if (error) - return error; - - kaddr = kmap_atomic(page, KM_USER0); - memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), - ip->i_di.di_size); - memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size); - kunmap_atomic(kaddr, KM_USER0); - flush_dcache_page(page); - brelse(dibh); - SetPageUptodate(page); - - return 0; -} - - -/** - * gfs2_readpage - readpage with locking - * @file: The file to read a page for. N.B. This may be NULL if we are - * reading an internal file. - * @page: The page to read - * - * Returns: errno - */ - -static int gfs2_readpage(struct file *file, struct page *page) -{ - struct gfs2_inode *ip = GFS2_I(page->mapping->host); - struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); - struct gfs2_file *gf = NULL; - struct gfs2_holder gh; - int error; - int do_unlock = 0; - - if (likely(file != &gfs2_internal_file_sentinel)) { - if (file) { - gf = file->private_data; - if (test_bit(GFF_EXLOCK, &gf->f_flags)) - /* gfs2_sharewrite_fault has grabbed the ip->i_gl already */ - goto skip_lock; - } - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh); - do_unlock = 1; - error = gfs2_glock_nq_atime(&gh); - if (unlikely(error)) - goto out_unlock; - } - -skip_lock: - if (gfs2_is_stuffed(ip)) { - error = stuffed_readpage(ip, page); - unlock_page(page); - } else - error = mpage_readpage(page, gfs2_get_block); - - if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) - error = -EIO; - - if (do_unlock) { - gfs2_glock_dq_m(1, &gh); - gfs2_holder_uninit(&gh); - } -out: - return error; -out_unlock: - unlock_page(page); - if (error == GLR_TRYFAILED) { - error = AOP_TRUNCATED_PAGE; - yield(); - } - if (do_unlock) - gfs2_holder_uninit(&gh); - goto out; -} - -/** - * gfs2_readpages - Read a bunch of pages at once - * - * 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_readpages() does most of the heavy lifting in the common case. - * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places. - * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as - * well as read-ahead. - */ -static int gfs2_readpages(struct file *file, struct address_space *mapping, - struct list_head *pages, unsigned nr_pages) -{ - struct inode *inode = mapping->host; - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_sbd *sdp = GFS2_SB(inode); - struct gfs2_holder gh; - int ret = 0; - int do_unlock = 0; - - if (likely(file != &gfs2_internal_file_sentinel)) { - if (file) { - struct gfs2_file *gf = file->private_data; - if (test_bit(GFF_EXLOCK, &gf->f_flags)) - goto skip_lock; - } - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, - LM_FLAG_TRY_1CB|GL_ATIME, &gh); - do_unlock = 1; - ret = gfs2_glock_nq_atime(&gh); - if (ret == GLR_TRYFAILED) - goto out_noerror; - if (unlikely(ret)) - goto out_unlock; - } -skip_lock: - if (!gfs2_is_stuffed(ip)) - ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block); - - if (do_unlock) { - gfs2_glock_dq_m(1, &gh); - gfs2_holder_uninit(&gh); - } -out: - if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) - ret = -EIO; - return ret; -out_noerror: - ret = 0; -out_unlock: - if (do_unlock) - gfs2_holder_uninit(&gh); - goto out; -} - -/** - * gfs2_write_begin - Begin to write to a file - * @file: The file to write to - * @mapping: The mapping in which to write - * @pos: The file offset at which to start writing - * @len: Length of the write - * @flags: Various flags - * @pagep: Pointer to return the page - * @fsdata: Pointer to return fs data (unused by GFS2) - * - * Returns: errno - */ - -static int gfs2_write_begin(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata) -{ - struct gfs2_inode *ip = GFS2_I(mapping->host); - struct gfs2_sbd *sdp = GFS2_SB(mapping->host); - unsigned int data_blocks, ind_blocks, rblocks; - int alloc_required; - int error = 0; - struct gfs2_alloc *al; - pgoff_t index = pos >> PAGE_CACHE_SHIFT; - unsigned from = pos & (PAGE_CACHE_SIZE - 1); - unsigned to = from + len; - struct page *page; - - gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh); - error = gfs2_glock_nq_atime(&ip->i_gh); - if (unlikely(error)) - goto out_uninit; - - error = -ENOMEM; - page = __grab_cache_page(mapping, index); - *pagep = page; - if (!page) - goto out_unlock; - - gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks); - - error = gfs2_write_alloc_required(ip, pos, len, &alloc_required); - if (error) - goto out_putpage; - - - ip->i_alloc.al_requested = 0; - if (alloc_required) { - al = gfs2_alloc_get(ip); - - error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); - if (error) - goto out_alloc_put; - - error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid); - if (error) - goto out_qunlock; - - al->al_requested = data_blocks + ind_blocks; - error = gfs2_inplace_reserve(ip); - if (error) - goto out_qunlock; - } - - rblocks = RES_DINODE + ind_blocks; - if (gfs2_is_jdata(ip)) - rblocks += data_blocks ? data_blocks : 1; - if (ind_blocks || data_blocks) - rblocks += RES_STATFS + RES_QUOTA; - - error = gfs2_trans_begin(sdp, rblocks, - PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize); - if (error) - goto out_trans_fail; - - if (gfs2_is_stuffed(ip)) { - if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { - error = gfs2_unstuff_dinode(ip, page); - if (error == 0) - goto prepare_write; - } else if (!PageUptodate(page)) - error = stuffed_readpage(ip, page); - goto out; - } - -prepare_write: - error = block_prepare_write(page, from, to, gfs2_get_block); - -out: - if (error) { - gfs2_trans_end(sdp); -out_trans_fail: - if (alloc_required) { - gfs2_inplace_release(ip); -out_qunlock: - gfs2_quota_unlock(ip); -out_alloc_put: - gfs2_alloc_put(ip); - } -out_putpage: - page_cache_release(page); - if (pos + len > ip->i_inode.i_size) - vmtruncate(&ip->i_inode, ip->i_inode.i_size); -out_unlock: - gfs2_glock_dq_m(1, &ip->i_gh); -out_uninit: - gfs2_holder_uninit(&ip->i_gh); - } - - return error; -} - -/** - * adjust_fs_space - Adjusts the free space available due to gfs2_grow - * @inode: the rindex inode - */ -static void adjust_fs_space(struct inode *inode) -{ - struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; - struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master; - struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; - u64 fs_total, new_free; - - /* Total up the file system space, according to the latest rindex. */ - fs_total = gfs2_ri_total(sdp); - - spin_lock(&sdp->sd_statfs_spin); - 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); -} - -/** - * gfs2_stuffed_write_end - Write end for stuffed files - * @inode: The inode - * @dibh: The buffer_head containing the on-disk inode - * @pos: The file position - * @len: The length of the write - * @copied: How much was actually copied by the VFS - * @page: The page - * - * This copies the data from the page into the inode block after - * the inode data structure itself. - * - * Returns: errno - */ -static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, - loff_t pos, unsigned len, unsigned copied, - struct page *page) -{ - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_sbd *sdp = GFS2_SB(inode); - u64 to = pos + copied; - void *kaddr; - unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode); - struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data; - - BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode))); - kaddr = kmap_atomic(page, KM_USER0); - memcpy(buf + pos, kaddr + pos, copied); - memset(kaddr + pos + copied, 0, len - copied); - flush_dcache_page(page); - kunmap_atomic(kaddr, KM_USER0); - - if (!PageUptodate(page)) - SetPageUptodate(page); - unlock_page(page); - page_cache_release(page); - - if (inode->i_size < to) { - i_size_write(inode, to); - ip->i_di.di_size = inode->i_size; - di->di_size = cpu_to_be64(inode->i_size); - mark_inode_dirty(inode); - } - - if (inode == sdp->sd_rindex) - adjust_fs_space(inode); - - brelse(dibh); - gfs2_trans_end(sdp); - gfs2_glock_dq(&ip->i_gh); - gfs2_holder_uninit(&ip->i_gh); - return copied; -} - -/** - * gfs2_write_end - * @file: The file to write to - * @mapping: The address space to write to - * @pos: The file position - * @len: The length of the data - * @copied: - * @page: The page that has been written - * @fsdata: The fsdata (unused in GFS2) - * - * The main write_end function for GFS2. We have a separate one for - * stuffed files as they are slightly different, otherwise we just - * put our locking around the VFS provided functions. - * - * Returns: errno - */ - -static int gfs2_write_end(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned copied, - struct page *page, void *fsdata) -{ - struct inode *inode = page->mapping->host; - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_sbd *sdp = GFS2_SB(inode); - struct buffer_head *dibh; - struct gfs2_alloc *al = &ip->i_alloc; - struct gfs2_dinode *di; - unsigned int from = pos & (PAGE_CACHE_SIZE - 1); - unsigned int to = from + len; - int ret; - - BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == 0); - - ret = gfs2_meta_inode_buffer(ip, &dibh); - if (unlikely(ret)) { - unlock_page(page); - page_cache_release(page); - goto failed; - } - - gfs2_trans_add_bh(ip->i_gl, dibh, 1); - - if (gfs2_is_stuffed(ip)) - return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page); - - if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) - gfs2_page_add_databufs(ip, page, from, to); - - ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); - - if (likely(ret >= 0)) { - copied = ret; - if ((pos + copied) > inode->i_size) { - di = (struct gfs2_dinode *)dibh->b_data; - ip->i_di.di_size = inode->i_size; - di->di_size = cpu_to_be64(inode->i_size); - mark_inode_dirty(inode); - } - } - - if (inode == sdp->sd_rindex) - adjust_fs_space(inode); - - brelse(dibh); - gfs2_trans_end(sdp); -failed: - if (al->al_requested) { - gfs2_inplace_release(ip); - gfs2_quota_unlock(ip); - gfs2_alloc_put(ip); - } - gfs2_glock_dq(&ip->i_gh); - gfs2_holder_uninit(&ip->i_gh); - return ret; -} - -/** - * gfs2_set_page_dirty - Page dirtying function - * @page: The page to dirty - * - * Returns: 1 if it dirtyed the page, or 0 otherwise - */ - -static int gfs2_set_page_dirty(struct page *page) -{ - struct gfs2_inode *ip = GFS2_I(page->mapping->host); - struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); - - if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) - SetPageChecked(page); - return __set_page_dirty_buffers(page); -} - -/** - * 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 = generic_block_bmap(mapping, lblock, gfs2_get_block); - - 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_le.le_list) && !buffer_pinned(bh)) - list_del_init(&bd->bd_le.le_list); - else - gfs2_remove_from_journal(bh, current->journal_info, 0); - } - 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_invalidatepage(struct page *page, unsigned long offset) -{ - struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); - struct buffer_head *bh, *head; - unsigned long pos = 0; - - BUG_ON(!PageLocked(page)); - if (offset == 0) - ClearPageChecked(page); - if (!page_has_buffers(page)) - goto out; - - bh = head = page_buffers(page); - do { - if (offset <= pos) - gfs2_discard(sdp, bh); - pos += bh->b_size; - bh = bh->b_this_page; - } while (bh != head); -out: - if (offset == 0) - try_to_release_page(page, 0); -} - -/** - * gfs2_ok_for_dio - check that dio is valid on this file - * @ip: The inode - * @rw: READ or WRITE - * @offset: The offset at which we are reading or writing - * - * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) - * 1 (to accept the i/o request) - */ -static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset) -{ - /* - * Should we return an error here? I can't see that O_DIRECT for - * a journaled file makes any sense. For now we'll silently fall - * back to buffered I/O, likewise we do the same for stuffed - * files since they are (a) small and (b) unaligned. - */ - if (gfs2_is_jdata(ip)) - return 0; - - if (gfs2_is_stuffed(ip)) - return 0; - - if (offset > i_size_read(&ip->i_inode)) - return 0; - return 1; -} - - - -static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, - const struct iovec *iov, loff_t offset, - unsigned long nr_segs) -{ - struct file *file = iocb->ki_filp; - struct inode *inode = file->f_mapping->host; - struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_holder gh; - int rv; - - /* - * Deferred lock, even if its a write, since we do no allocation - * on this path. All we need change is atime, and this lock mode - * ensures that other nodes have flushed their buffered read caches - * (i.e. their page cache entries for this inode). We do not, - * unfortunately have the option of only flushing a range like - * the VFS does. - */ - gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, GL_ATIME, &gh); - rv = gfs2_glock_nq_atime(&gh); - if (rv) - return rv; - rv = gfs2_ok_for_dio(ip, rw, offset); - if (rv != 1) - goto out; /* dio not valid, fall back to buffered i/o */ - - rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev, - iov, offset, nr_segs, - gfs2_get_block_direct, NULL); -out: - gfs2_glock_dq_m(1, &gh); - gfs2_holder_uninit(&gh); - return rv; -} - -/** - * gfs2_releasepage - free the metadata associated with a page - * @page: the page that's being released - * @gfp_mask: passed from Linux VFS, ignored by us - * - * Call try_to_free_buffers() if the buffers in this page can be - * released. - * - * Returns: 0 - */ - -int gfs2_releasepage(struct page *page, gfp_t gfp_mask) -{ - struct inode *aspace = page->mapping->host; - struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info; - struct buffer_head *bh, *head; - struct gfs2_bufdata *bd; - - if (!page_has_buffers(page)) - return 0; - - gfs2_log_lock(sdp); - head = bh = page_buffers(page); - do { - if (atomic_read(&bh->b_count)) - goto cannot_release; - bd = bh->b_private; - if (bd && bd->bd_ail) - goto cannot_release; - gfs2_assert_warn(sdp, !buffer_pinned(bh)); - gfs2_assert_warn(sdp, !buffer_dirty(bh)); - bh = bh->b_this_page; - } while(bh != head); - gfs2_log_unlock(sdp); - - head = bh = page_buffers(page); - do { - gfs2_log_lock(sdp); - bd = bh->b_private; - if (bd) { - gfs2_assert_warn(sdp, bd->bd_bh == bh); - gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr)); - if (!list_empty(&bd->bd_le.le_list)) { - if (!buffer_pinned(bh)) - list_del_init(&bd->bd_le.le_list); - else - bd = NULL; - } - if (bd) - bd->bd_bh = NULL; - bh->b_private = NULL; - } - gfs2_log_unlock(sdp); - if (bd) - kmem_cache_free(gfs2_bufdata_cachep, bd); - - bh = bh->b_this_page; - } while (bh != head); - - return try_to_free_buffers(page); -cannot_release: - gfs2_log_unlock(sdp); - return 0; -} - -const struct address_space_operations gfs2_file_aops = { - .writepage = gfs2_writepage, - .writepages = gfs2_writepages, - .readpage = gfs2_readpage, - .readpages = gfs2_readpages, - .sync_page = block_sync_page, - .write_begin = gfs2_write_begin, - .write_end = gfs2_write_end, - .set_page_dirty = gfs2_set_page_dirty, - .bmap = gfs2_bmap, - .invalidatepage = gfs2_invalidatepage, - .releasepage = gfs2_releasepage, - .direct_IO = gfs2_direct_IO, -}; - |