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https://gitee.com/bianbu-linux/linux-6.6
synced 2025-07-22 01:43:37 -04:00
289c6aedac
This is practically generic code; other filesystems will want to call it from other places, but there's nothing ext2-specific about it. Make it a little more generic by allowing it to take a count of the number of bytes to zero rather than fixing it to a single page. Thanks to Dave Hansen for suggesting that I need to call cond_resched() if zeroing more than one page. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/*
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* linux/fs/ext2/xip.c
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*
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* Copyright (C) 2005 IBM Corporation
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* Author: Carsten Otte (cotte@de.ibm.com)
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*/
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/genhd.h>
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#include <linux/buffer_head.h>
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#include <linux/blkdev.h>
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#include "ext2.h"
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#include "xip.h"
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static inline long __inode_direct_access(struct inode *inode, sector_t block,
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void **kaddr, unsigned long *pfn, long size)
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{
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struct block_device *bdev = inode->i_sb->s_bdev;
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sector_t sector = block * (PAGE_SIZE / 512);
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return bdev_direct_access(bdev, sector, kaddr, pfn, size);
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}
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static inline int
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__ext2_get_block(struct inode *inode, pgoff_t pgoff, int create,
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sector_t *result)
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{
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struct buffer_head tmp;
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int rc;
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memset(&tmp, 0, sizeof(struct buffer_head));
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tmp.b_size = 1 << inode->i_blkbits;
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rc = ext2_get_block(inode, pgoff, &tmp, create);
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*result = tmp.b_blocknr;
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/* did we get a sparse block (hole in the file)? */
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if (!tmp.b_blocknr && !rc) {
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BUG_ON(create);
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rc = -ENODATA;
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}
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return rc;
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}
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void ext2_xip_verify_sb(struct super_block *sb)
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{
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struct ext2_sb_info *sbi = EXT2_SB(sb);
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if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) &&
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!sb->s_bdev->bd_disk->fops->direct_access) {
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sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
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ext2_msg(sb, KERN_WARNING,
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"warning: ignoring xip option - "
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"not supported by bdev");
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}
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}
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int ext2_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create,
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void **kmem, unsigned long *pfn)
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{
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long rc;
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sector_t block;
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/* first, retrieve the sector number */
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rc = __ext2_get_block(mapping->host, pgoff, create, &block);
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if (rc)
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return rc;
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/* retrieve address of the target data */
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rc = __inode_direct_access(mapping->host, block, kmem, pfn, PAGE_SIZE);
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return (rc < 0) ? rc : 0;
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}
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