diff options
Diffstat (limited to 'fs/gfs2/ops_address.c')
| -rw-r--r-- | fs/gfs2/ops_address.c | 515 |
1 files changed, 515 insertions, 0 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c new file mode 100644 index 00000000000..0aa5f140ddb --- /dev/null +++ b/fs/gfs2/ops_address.c @@ -0,0 +1,515 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 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 v.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 <asm/semaphore.h> + +#include "gfs2.h" +#include "bmap.h" +#include "glock.h" +#include "inode.h" +#include "jdata.h" +#include "log.h" +#include "meta_io.h" +#include "ops_address.h" +#include "page.h" +#include "quota.h" +#include "trans.h" + +/** + * 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 + */ + +static int get_block(struct inode *inode, sector_t lblock, + struct buffer_head *bh_result, int create) +{ + struct gfs2_inode *ip = get_v2ip(inode); + int new = create; + uint64_t dblock; + int error; + + error = gfs2_block_map(ip, lblock, &new, &dblock, NULL); + if (error) + return error; + + if (!dblock) + return 0; + + map_bh(bh_result, inode->i_sb, dblock); + if (new) + set_buffer_new(bh_result); + + return 0; +} + +/** + * 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 get_block_noalloc(struct inode *inode, sector_t lblock, + struct buffer_head *bh_result, int create) +{ + struct gfs2_inode *ip = get_v2ip(inode); + int new = 0; + uint64_t dblock; + int error; + + error = gfs2_block_map(ip, lblock, &new, &dblock, NULL); + if (error) + return error; + + if (dblock) + map_bh(bh_result, inode->i_sb, dblock); + else if (gfs2_assert_withdraw(ip->i_sbd, !create)) + error = -EIO; + + return error; +} + +static int get_blocks(struct inode *inode, sector_t lblock, + unsigned long max_blocks, struct buffer_head *bh_result, + int create) +{ + struct gfs2_inode *ip = get_v2ip(inode); + int new = create; + uint64_t dblock; + uint32_t extlen; + int error; + + error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen); + if (error) + return error; + + if (!dblock) + return 0; + + map_bh(bh_result, inode->i_sb, dblock); + if (new) + set_buffer_new(bh_result); + + if (extlen > max_blocks) + extlen = max_blocks; + bh_result->b_size = extlen << inode->i_blkbits; + + return 0; +} + +static int get_blocks_noalloc(struct inode *inode, sector_t lblock, + unsigned long max_blocks, + struct buffer_head *bh_result, int create) +{ + struct gfs2_inode *ip = get_v2ip(inode); + int new = 0; + uint64_t dblock; + uint32_t extlen; + int error; + + error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen); + if (error) + return error; + + if (dblock) { + map_bh(bh_result, inode->i_sb, dblock); + if (extlen > max_blocks) + extlen = max_blocks; + bh_result->b_size = extlen << inode->i_blkbits; + } else if (gfs2_assert_withdraw(ip->i_sbd, !create)) + error = -EIO; + + return error; +} + +/** + * gfs2_writepage - Write complete page + * @page: Page to write + * + * Returns: errno + * + * Use Linux VFS block_write_full_page() to write one page, + * using GFS2's get_block_noalloc to find which blocks to write. + */ + +static int gfs2_writepage(struct page *page, struct writeback_control *wbc) +{ + struct gfs2_inode *ip = get_v2ip(page->mapping->host); + struct gfs2_sbd *sdp = ip->i_sbd; + int error; + + atomic_inc(&sdp->sd_ops_address); + + if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) { + unlock_page(page); + return -EIO; + } + if (get_transaction) { + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return 0; + } + + error = block_write_full_page(page, get_block_noalloc, wbc); + + gfs2_meta_cache_flush(ip); + + return error; +} + +/** + * 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; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + return error; + + kaddr = kmap(page); + memcpy((char *)kaddr, + dibh->b_data + sizeof(struct gfs2_dinode), + ip->i_di.di_size); + memset((char *)kaddr + ip->i_di.di_size, + 0, + PAGE_CACHE_SIZE - ip->i_di.di_size); + kunmap(page); + + brelse(dibh); + + SetPageUptodate(page); + + return 0; +} + +static int zero_readpage(struct page *page) +{ + void *kaddr; + + kaddr = kmap(page); + memset(kaddr, 0, PAGE_CACHE_SIZE); + kunmap(page); + + SetPageUptodate(page); + unlock_page(page); + + return 0; +} + +/** + * jdata_readpage - readpage that goes through gfs2_jdata_read_mem() + * @ip: + * @page: The page to read + * + * Returns: errno + */ + +static int jdata_readpage(struct gfs2_inode *ip, struct page *page) +{ + void *kaddr; + int ret; + + kaddr = kmap(page); + + ret = gfs2_jdata_read_mem(ip, kaddr, + (uint64_t)page->index << PAGE_CACHE_SHIFT, + PAGE_CACHE_SIZE); + if (ret >= 0) { + if (ret < PAGE_CACHE_SIZE) + memset(kaddr + ret, 0, PAGE_CACHE_SIZE - ret); + SetPageUptodate(page); + ret = 0; + } + + kunmap(page); + + unlock_page(page); + + return ret; +} + +/** + * gfs2_readpage - readpage with locking + * @file: The file to read a page for + * @page: The page to read + * + * Returns: errno + */ + +static int gfs2_readpage(struct file *file, struct page *page) +{ + struct gfs2_inode *ip = get_v2ip(page->mapping->host); + struct gfs2_sbd *sdp = ip->i_sbd; + int error; + + atomic_inc(&sdp->sd_ops_address); + + if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) { + unlock_page(page); + return -EOPNOTSUPP; + } + + if (!gfs2_is_jdata(ip)) { + if (gfs2_is_stuffed(ip)) { + if (!page->index) { + error = stuffed_readpage(ip, page); + unlock_page(page); + } else + error = zero_readpage(page); + } else + error = block_read_full_page(page, get_block); + } else + error = jdata_readpage(ip, page); + + if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) + error = -EIO; + + return error; +} + +/** + * gfs2_prepare_write - Prepare to write a page to a file + * @file: The file to write to + * @page: The page which is to be prepared for writing + * @from: From (byte range within page) + * @to: To (byte range within page) + * + * Returns: errno + */ + +static int gfs2_prepare_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + struct gfs2_inode *ip = get_v2ip(page->mapping->host); + struct gfs2_sbd *sdp = ip->i_sbd; + int error = 0; + + atomic_inc(&sdp->sd_ops_address); + + if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) + return -EOPNOTSUPP; + + if (gfs2_is_stuffed(ip)) { + uint64_t file_size; + file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to; + + if (file_size > sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_dinode)) { + error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, + page); + if (!error) + error = block_prepare_write(page, from, to, + get_block); + } else if (!PageUptodate(page)) + error = stuffed_readpage(ip, page); + } else + error = block_prepare_write(page, from, to, get_block); + + return error; +} + +/** + * gfs2_commit_write - Commit write to a file + * @file: The file to write to + * @page: The page containing the data + * @from: From (byte range within page) + * @to: To (byte range within page) + * + * Returns: errno + */ + +static int gfs2_commit_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + struct inode *inode = page->mapping->host; + struct gfs2_inode *ip = get_v2ip(inode); + struct gfs2_sbd *sdp = ip->i_sbd; + int error; + + atomic_inc(&sdp->sd_ops_address); + + if (gfs2_is_stuffed(ip)) { + struct buffer_head *dibh; + uint64_t file_size; + void *kaddr; + + file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto fail; + + gfs2_trans_add_bh(ip->i_gl, dibh); + + kaddr = kmap(page); + memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from, + (char *)kaddr + from, + to - from); + kunmap(page); + + brelse(dibh); + + SetPageUptodate(page); + + if (inode->i_size < file_size) + i_size_write(inode, file_size); + } else { + if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED) + gfs2_page_add_databufs(sdp, page, from, to); + error = generic_commit_write(file, page, from, to); + if (error) + goto fail; + } + + return 0; + + fail: + ClearPageUptodate(page); + + return error; +} + +/** + * 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 = get_v2ip(mapping->host); + struct gfs2_holder i_gh; + sector_t dblock = 0; + int error; + + atomic_inc(&ip->i_sbd->sd_ops_address); + + 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, get_block); + + gfs2_glock_dq_uninit(&i_gh); + + return dblock; +} + +static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh) +{ + struct gfs2_databuf *db; + + gfs2_log_lock(sdp); + db = get_v2db(bh); + if (db) { + db->db_bh = NULL; + set_v2db(bh, NULL); + gfs2_log_unlock(sdp); + brelse(bh); + } else + gfs2_log_unlock(sdp); + + lock_buffer(bh); + clear_buffer_dirty(bh); + bh->b_bdev = NULL; + clear_buffer_mapped(bh); + clear_buffer_req(bh); + clear_buffer_new(bh); + clear_buffer_delay(bh); + unlock_buffer(bh); +} + +static int gfs2_invalidatepage(struct page *page, unsigned long offset) +{ + struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb); + struct buffer_head *head, *bh, *next; + unsigned int curr_off = 0; + int ret = 1; + + BUG_ON(!PageLocked(page)); + if (!page_has_buffers(page)) + return 1; + + bh = head = page_buffers(page); + do { + unsigned int next_off = curr_off + bh->b_size; + next = bh->b_this_page; + + if (offset <= curr_off) + discard_buffer(sdp, bh); + + curr_off = next_off; + bh = next; + } while (bh != head); + + if (!offset) + ret = try_to_release_page(page, 0); + + return ret; +} + +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 = get_v2ip(inode); + struct gfs2_sbd *sdp = ip->i_sbd; + get_blocks_t *gb = get_blocks; + + atomic_inc(&sdp->sd_ops_address); + + if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) || + gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip))) + return -EINVAL; + + if (rw == WRITE && !get_transaction) + gb = get_blocks_noalloc; + + return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, + offset, nr_segs, gb, NULL); +} + +struct address_space_operations gfs2_file_aops = { + .writepage = gfs2_writepage, + .readpage = gfs2_readpage, + .sync_page = block_sync_page, + .prepare_write = gfs2_prepare_write, + .commit_write = gfs2_commit_write, + .bmap = gfs2_bmap, + .invalidatepage = gfs2_invalidatepage, + .direct_IO = gfs2_direct_IO, +}; + |