Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/ext2/xip.c |
| 3 | * |
| 4 | * Copyright (C) 2005 IBM Corporation |
| 5 | * Author: Carsten Otte (cotte@de.ibm.com) |
| 6 | */ |
| 7 | |
| 8 | #include <linux/mm.h> |
| 9 | #include <linux/fs.h> |
| 10 | #include <linux/genhd.h> |
| 11 | #include <linux/buffer_head.h> |
Al Viro | 08f8585 | 2007-10-08 13:26:20 -0400 | [diff] [blame] | 12 | #include <linux/blkdev.h> |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 13 | #include "ext2.h" |
| 14 | #include "xip.h" |
| 15 | |
Matthew Wilcox | dd22f55 | 2015-01-07 18:05:34 +0200 | [diff] [blame] | 16 | static inline long __inode_direct_access(struct inode *inode, sector_t block, |
| 17 | void **kaddr, unsigned long *pfn, long size) |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 18 | { |
Jared Hulbert | 30afcb4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 19 | struct block_device *bdev = inode->i_sb->s_bdev; |
Matthew Wilcox | dd22f55 | 2015-01-07 18:05:34 +0200 | [diff] [blame] | 20 | sector_t sector = block * (PAGE_SIZE / 512); |
| 21 | return bdev_direct_access(bdev, sector, kaddr, pfn, size); |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 22 | } |
| 23 | |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 24 | static inline int |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 25 | __ext2_get_block(struct inode *inode, pgoff_t pgoff, int create, |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 26 | sector_t *result) |
| 27 | { |
| 28 | struct buffer_head tmp; |
| 29 | int rc; |
| 30 | |
| 31 | memset(&tmp, 0, sizeof(struct buffer_head)); |
Jan Kara | 7ba3ec5 | 2013-11-05 01:15:38 +0100 | [diff] [blame] | 32 | tmp.b_size = 1 << inode->i_blkbits; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 33 | rc = ext2_get_block(inode, pgoff, &tmp, create); |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 34 | *result = tmp.b_blocknr; |
| 35 | |
| 36 | /* did we get a sparse block (hole in the file)? */ |
Carsten Otte | 0cfc11e | 2005-07-27 11:43:52 -0700 | [diff] [blame] | 37 | if (!tmp.b_blocknr && !rc) { |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 38 | BUG_ON(create); |
| 39 | rc = -ENODATA; |
| 40 | } |
| 41 | |
| 42 | return rc; |
| 43 | } |
| 44 | |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 45 | void ext2_xip_verify_sb(struct super_block *sb) |
| 46 | { |
| 47 | struct ext2_sb_info *sbi = EXT2_SB(sb); |
| 48 | |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 49 | if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) && |
| 50 | !sb->s_bdev->bd_disk->fops->direct_access) { |
| 51 | sbi->s_mount_opt &= (~EXT2_MOUNT_XIP); |
Alexey Fisher | 2314b07 | 2009-11-19 19:12:51 +0100 | [diff] [blame] | 52 | ext2_msg(sb, KERN_WARNING, |
| 53 | "warning: ignoring xip option - " |
| 54 | "not supported by bdev"); |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 55 | } |
| 56 | } |
| 57 | |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 58 | int ext2_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create, |
| 59 | void **kmem, unsigned long *pfn) |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 60 | { |
Matthew Wilcox | dd22f55 | 2015-01-07 18:05:34 +0200 | [diff] [blame] | 61 | long rc; |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 62 | sector_t block; |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 63 | |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 64 | /* first, retrieve the sector number */ |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 65 | rc = __ext2_get_block(mapping->host, pgoff, create, &block); |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 66 | if (rc) |
Nick Piggin | 70688e4 | 2008-04-28 02:13:02 -0700 | [diff] [blame] | 67 | return rc; |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 68 | |
Carsten Otte | afa597b | 2005-07-15 03:56:30 -0700 | [diff] [blame] | 69 | /* retrieve address of the target data */ |
Matthew Wilcox | dd22f55 | 2015-01-07 18:05:34 +0200 | [diff] [blame] | 70 | rc = __inode_direct_access(mapping->host, block, kmem, pfn, PAGE_SIZE); |
| 71 | return (rc < 0) ? rc : 0; |
Carsten Otte | 6d79125 | 2005-06-23 22:05:26 -0700 | [diff] [blame] | 72 | } |