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Diffstat (limited to 'fs/freevxfs/vxfs_subr.c')
| -rw-r--r-- | fs/freevxfs/vxfs_subr.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/fs/freevxfs/vxfs_subr.c b/fs/freevxfs/vxfs_subr.c new file mode 100644 index 000000000000..5e305612054a --- /dev/null +++ b/fs/freevxfs/vxfs_subr.c @@ -0,0 +1,190 @@ +/* + * Copyright (c) 2000-2001 Christoph Hellwig. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL"). + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Veritas filesystem driver - shared subroutines. + */ +#include <linux/fs.h> +#include <linux/buffer_head.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/pagemap.h> + +#include "vxfs_kcompat.h" +#include "vxfs_extern.h" + + +static int vxfs_readpage(struct file *, struct page *); +static sector_t vxfs_bmap(struct address_space *, sector_t); + +struct address_space_operations vxfs_aops = { + .readpage = vxfs_readpage, + .bmap = vxfs_bmap, + .sync_page = block_sync_page, +}; + +inline void +vxfs_put_page(struct page *pp) +{ + kunmap(pp); + page_cache_release(pp); +} + +/** + * vxfs_get_page - read a page into memory. + * @ip: inode to read from + * @n: page number + * + * Description: + * vxfs_get_page reads the @n th page of @ip into the pagecache. + * + * Returns: + * The wanted page on success, else a NULL pointer. + */ +struct page * +vxfs_get_page(struct address_space *mapping, u_long n) +{ + struct page * pp; + + pp = read_cache_page(mapping, n, + (filler_t*)mapping->a_ops->readpage, NULL); + + if (!IS_ERR(pp)) { + wait_on_page_locked(pp); + kmap(pp); + if (!PageUptodate(pp)) + goto fail; + /** if (!PageChecked(pp)) **/ + /** vxfs_check_page(pp); **/ + if (PageError(pp)) + goto fail; + } + + return (pp); + +fail: + vxfs_put_page(pp); + return ERR_PTR(-EIO); +} + +/** + * vxfs_bread - read buffer for a give inode,block tuple + * @ip: inode + * @block: logical block + * + * Description: + * The vxfs_bread function reads block no @block of + * @ip into the buffercache. + * + * Returns: + * The resulting &struct buffer_head. + */ +struct buffer_head * +vxfs_bread(struct inode *ip, int block) +{ + struct buffer_head *bp; + daddr_t pblock; + + pblock = vxfs_bmap1(ip, block); + bp = sb_bread(ip->i_sb, pblock); + + return (bp); +} + +/** + * vxfs_get_block - locate buffer for given inode,block tuple + * @ip: inode + * @iblock: logical block + * @bp: buffer skeleton + * @create: %TRUE if blocks may be newly allocated. + * + * Description: + * The vxfs_get_block function fills @bp with the right physical + * block and device number to perform a lowlevel read/write on + * it. + * + * Returns: + * Zero on success, else a negativ error code (-EIO). + */ +static int +vxfs_getblk(struct inode *ip, sector_t iblock, + struct buffer_head *bp, int create) +{ + daddr_t pblock; + + pblock = vxfs_bmap1(ip, iblock); + if (pblock != 0) { + map_bh(bp, ip->i_sb, pblock); + return 0; + } + + return -EIO; +} + +/** + * vxfs_readpage - read one page synchronously into the pagecache + * @file: file context (unused) + * @page: page frame to fill in. + * + * Description: + * The vxfs_readpage routine reads @page synchronously into the + * pagecache. + * + * Returns: + * Zero on success, else a negative error code. + * + * Locking status: + * @page is locked and will be unlocked. + */ +static int +vxfs_readpage(struct file *file, struct page *page) +{ + return block_read_full_page(page, vxfs_getblk); +} + +/** + * vxfs_bmap - perform logical to physical block mapping + * @mapping: logical to physical mapping to use + * @block: logical block (relative to @mapping). + * + * Description: + * Vxfs_bmap find out the corresponding phsical block to the + * @mapping, @block pair. + * + * Returns: + * Physical block number on success, else Zero. + * + * Locking status: + * We are under the bkl. + */ +static sector_t +vxfs_bmap(struct address_space *mapping, sector_t block) +{ + return generic_block_bmap(mapping, block, vxfs_getblk); +} |