Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/block_dev.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE |
| 6 | */ |
| 7 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/init.h> |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/fcntl.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/kmod.h> |
| 13 | #include <linux/major.h> |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 14 | #include <linux/device_cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/highmem.h> |
| 16 | #include <linux/blkdev.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/blkpg.h> |
Muthu Kumar | b502bd1 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 19 | #include <linux/magic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/buffer_head.h> |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 21 | #include <linux/swap.h> |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 22 | #include <linux/pagevec.h> |
David Howells | 811d736 | 2006-08-29 19:06:09 +0100 | [diff] [blame] | 23 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/mpage.h> |
| 25 | #include <linux/mount.h> |
| 26 | #include <linux/uio.h> |
| 27 | #include <linux/namei.h> |
Vignesh Babu BM | 1368c4f | 2007-05-08 00:24:32 -0700 | [diff] [blame] | 28 | #include <linux/log2.h> |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 29 | #include <linux/cleancache.h> |
Kent Overstreet | a27bb33 | 2013-05-07 16:19:08 -0700 | [diff] [blame] | 30 | #include <linux/aio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <asm/uaccess.h> |
David Howells | 07f3f05c | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 32 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
| 34 | struct bdev_inode { |
| 35 | struct block_device bdev; |
| 36 | struct inode vfs_inode; |
| 37 | }; |
| 38 | |
Adrian Bunk | 4c54ac6 | 2008-02-18 13:48:31 +0100 | [diff] [blame] | 39 | static const struct address_space_operations def_blk_aops; |
| 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | static inline struct bdev_inode *BDEV_I(struct inode *inode) |
| 42 | { |
| 43 | return container_of(inode, struct bdev_inode, vfs_inode); |
| 44 | } |
| 45 | |
| 46 | inline struct block_device *I_BDEV(struct inode *inode) |
| 47 | { |
| 48 | return &BDEV_I(inode)->bdev; |
| 49 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | EXPORT_SYMBOL(I_BDEV); |
| 51 | |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 52 | /* |
Tejun Heo | 018a17b | 2014-09-08 08:04:01 +0900 | [diff] [blame] | 53 | * Move the inode from its current bdi to a new bdi. Make sure the inode |
| 54 | * is clean before moving so that it doesn't linger on the old bdi. |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 55 | */ |
| 56 | static void bdev_inode_switch_bdi(struct inode *inode, |
| 57 | struct backing_dev_info *dst) |
| 58 | { |
Tejun Heo | 018a17b | 2014-09-08 08:04:01 +0900 | [diff] [blame] | 59 | while (true) { |
| 60 | spin_lock(&inode->i_lock); |
| 61 | if (!(inode->i_state & I_DIRTY)) { |
| 62 | inode->i_data.backing_dev_info = dst; |
| 63 | spin_unlock(&inode->i_lock); |
| 64 | return; |
| 65 | } |
| 66 | spin_unlock(&inode->i_lock); |
| 67 | WARN_ON_ONCE(write_inode_now(inode, true)); |
Jan Kara | a5faeaf | 2013-06-28 16:04:02 +0200 | [diff] [blame] | 68 | } |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 69 | } |
| 70 | |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 71 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 72 | void kill_bdev(struct block_device *bdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | { |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 74 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
| 75 | |
Johannes Weiner | 91b0abe | 2014-04-03 14:47:49 -0700 | [diff] [blame] | 76 | if (mapping->nrpages == 0 && mapping->nrshadows == 0) |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 77 | return; |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 78 | |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 79 | invalidate_bh_lrus(); |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 80 | truncate_inode_pages(mapping, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | } |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 82 | EXPORT_SYMBOL(kill_bdev); |
| 83 | |
| 84 | /* Invalidate clean unused buffers and pagecache. */ |
| 85 | void invalidate_bdev(struct block_device *bdev) |
| 86 | { |
| 87 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
| 88 | |
| 89 | if (mapping->nrpages == 0) |
| 90 | return; |
| 91 | |
| 92 | invalidate_bh_lrus(); |
| 93 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ |
| 94 | invalidate_mapping_pages(mapping, 0, -1); |
| 95 | /* 99% of the time, we don't need to flush the cleancache on the bdev. |
| 96 | * But, for the strange corners, lets be cautious |
| 97 | */ |
Dan Magenheimer | 3167760 | 2011-09-21 11:56:28 -0400 | [diff] [blame] | 98 | cleancache_invalidate_inode(mapping); |
Al Viro | ff01bb4 | 2011-09-16 02:31:11 -0400 | [diff] [blame] | 99 | } |
| 100 | EXPORT_SYMBOL(invalidate_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | |
| 102 | int set_blocksize(struct block_device *bdev, int size) |
| 103 | { |
| 104 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ |
Vignesh Babu BM | 1368c4f | 2007-05-08 00:24:32 -0700 | [diff] [blame] | 105 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | return -EINVAL; |
| 107 | |
| 108 | /* Size cannot be smaller than the size supported by the device */ |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 109 | if (size < bdev_logical_block_size(bdev)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | return -EINVAL; |
| 111 | |
| 112 | /* Don't change the size if it is same as current */ |
| 113 | if (bdev->bd_block_size != size) { |
| 114 | sync_blockdev(bdev); |
| 115 | bdev->bd_block_size = size; |
| 116 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
| 117 | kill_bdev(bdev); |
| 118 | } |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | EXPORT_SYMBOL(set_blocksize); |
| 123 | |
| 124 | int sb_set_blocksize(struct super_block *sb, int size) |
| 125 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | if (set_blocksize(sb->s_bdev, size)) |
| 127 | return 0; |
| 128 | /* If we get here, we know size is power of two |
| 129 | * and it's value is between 512 and PAGE_SIZE */ |
| 130 | sb->s_blocksize = size; |
Coywolf Qi Hunt | 38885bd | 2006-03-24 03:18:05 -0800 | [diff] [blame] | 131 | sb->s_blocksize_bits = blksize_bits(size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | return sb->s_blocksize; |
| 133 | } |
| 134 | |
| 135 | EXPORT_SYMBOL(sb_set_blocksize); |
| 136 | |
| 137 | int sb_min_blocksize(struct super_block *sb, int size) |
| 138 | { |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 139 | int minsize = bdev_logical_block_size(sb->s_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | if (size < minsize) |
| 141 | size = minsize; |
| 142 | return sb_set_blocksize(sb, size); |
| 143 | } |
| 144 | |
| 145 | EXPORT_SYMBOL(sb_min_blocksize); |
| 146 | |
| 147 | static int |
| 148 | blkdev_get_block(struct inode *inode, sector_t iblock, |
| 149 | struct buffer_head *bh, int create) |
| 150 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | bh->b_bdev = I_BDEV(inode); |
| 152 | bh->b_blocknr = iblock; |
| 153 | set_buffer_mapped(bh); |
| 154 | return 0; |
| 155 | } |
| 156 | |
Andrew Morton | b2e895d | 2007-02-03 01:14:01 -0800 | [diff] [blame] | 157 | static ssize_t |
Al Viro | d8d3d94 | 2014-03-04 21:27:34 -0500 | [diff] [blame] | 158 | blkdev_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, |
| 159 | loff_t offset) |
Andrew Morton | b2e895d | 2007-02-03 01:14:01 -0800 | [diff] [blame] | 160 | { |
| 161 | struct file *file = iocb->ki_filp; |
| 162 | struct inode *inode = file->f_mapping->host; |
| 163 | |
Al Viro | 31b1403 | 2014-03-05 01:33:16 -0500 | [diff] [blame] | 164 | return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iter, |
| 165 | offset, blkdev_get_block, |
Al Viro | d8d3d94 | 2014-03-04 21:27:34 -0500 | [diff] [blame] | 166 | NULL, NULL, 0); |
Andrew Morton | b2e895d | 2007-02-03 01:14:01 -0800 | [diff] [blame] | 167 | } |
| 168 | |
Jan Kara | 5cee581 | 2009-04-27 16:43:51 +0200 | [diff] [blame] | 169 | int __sync_blockdev(struct block_device *bdev, int wait) |
| 170 | { |
| 171 | if (!bdev) |
| 172 | return 0; |
| 173 | if (!wait) |
| 174 | return filemap_flush(bdev->bd_inode->i_mapping); |
| 175 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); |
| 176 | } |
| 177 | |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 178 | /* |
| 179 | * Write out and wait upon all the dirty data associated with a block |
| 180 | * device via its mapping. Does not take the superblock lock. |
| 181 | */ |
| 182 | int sync_blockdev(struct block_device *bdev) |
| 183 | { |
Jan Kara | 5cee581 | 2009-04-27 16:43:51 +0200 | [diff] [blame] | 184 | return __sync_blockdev(bdev, 1); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 185 | } |
| 186 | EXPORT_SYMBOL(sync_blockdev); |
| 187 | |
| 188 | /* |
| 189 | * Write out and wait upon all dirty data associated with this |
| 190 | * device. Filesystem data as well as the underlying block |
| 191 | * device. Takes the superblock lock. |
| 192 | */ |
| 193 | int fsync_bdev(struct block_device *bdev) |
| 194 | { |
| 195 | struct super_block *sb = get_super(bdev); |
| 196 | if (sb) { |
Jan Kara | 60b0680 | 2009-04-27 16:43:53 +0200 | [diff] [blame] | 197 | int res = sync_filesystem(sb); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 198 | drop_super(sb); |
| 199 | return res; |
| 200 | } |
| 201 | return sync_blockdev(bdev); |
| 202 | } |
Al Viro | 47e4491 | 2009-04-01 07:07:16 -0400 | [diff] [blame] | 203 | EXPORT_SYMBOL(fsync_bdev); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 204 | |
| 205 | /** |
| 206 | * freeze_bdev -- lock a filesystem and force it into a consistent state |
| 207 | * @bdev: blockdevice to lock |
| 208 | * |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 209 | * If a superblock is found on this device, we take the s_umount semaphore |
| 210 | * on it to make sure nobody unmounts until the snapshot creation is done. |
| 211 | * The reference counter (bd_fsfreeze_count) guarantees that only the last |
| 212 | * unfreeze process can unfreeze the frozen filesystem actually when multiple |
| 213 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and |
| 214 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze |
| 215 | * actually. |
| 216 | */ |
| 217 | struct super_block *freeze_bdev(struct block_device *bdev) |
| 218 | { |
| 219 | struct super_block *sb; |
| 220 | int error = 0; |
| 221 | |
| 222 | mutex_lock(&bdev->bd_fsfreeze_mutex); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 223 | if (++bdev->bd_fsfreeze_count > 1) { |
| 224 | /* |
| 225 | * We don't even need to grab a reference - the first call |
| 226 | * to freeze_bdev grab an active reference and only the last |
| 227 | * thaw_bdev drops it. |
| 228 | */ |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 229 | sb = get_super(bdev); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 230 | drop_super(sb); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 231 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 232 | return sb; |
| 233 | } |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 234 | |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 235 | sb = get_active_super(bdev); |
| 236 | if (!sb) |
| 237 | goto out; |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 238 | error = freeze_super(sb); |
| 239 | if (error) { |
| 240 | deactivate_super(sb); |
| 241 | bdev->bd_fsfreeze_count--; |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 242 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 243 | return ERR_PTR(error); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 244 | } |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 245 | deactivate_super(sb); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 246 | out: |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 247 | sync_blockdev(bdev); |
| 248 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
Christoph Hellwig | 4fadd7b | 2009-08-03 23:28:06 +0200 | [diff] [blame] | 249 | return sb; /* thaw_bdev releases s->s_umount */ |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 250 | } |
| 251 | EXPORT_SYMBOL(freeze_bdev); |
| 252 | |
| 253 | /** |
| 254 | * thaw_bdev -- unlock filesystem |
| 255 | * @bdev: blockdevice to unlock |
| 256 | * @sb: associated superblock |
| 257 | * |
| 258 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). |
| 259 | */ |
| 260 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) |
| 261 | { |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 262 | int error = -EINVAL; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 263 | |
| 264 | mutex_lock(&bdev->bd_fsfreeze_mutex); |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 265 | if (!bdev->bd_fsfreeze_count) |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 266 | goto out; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 267 | |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 268 | error = 0; |
| 269 | if (--bdev->bd_fsfreeze_count > 0) |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 270 | goto out; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 271 | |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 272 | if (!sb) |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 273 | goto out; |
Christoph Hellwig | 4504230 | 2009-08-03 23:28:35 +0200 | [diff] [blame] | 274 | |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 275 | error = thaw_super(sb); |
| 276 | if (error) { |
| 277 | bdev->bd_fsfreeze_count++; |
| 278 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 279 | return error; |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 280 | } |
Josef Bacik | 18e9e51 | 2010-03-23 10:34:56 -0400 | [diff] [blame] | 281 | out: |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 282 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 283 | return 0; |
| 284 | } |
| 285 | EXPORT_SYMBOL(thaw_bdev); |
| 286 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
| 288 | { |
| 289 | return block_write_full_page(page, blkdev_get_block, wbc); |
| 290 | } |
| 291 | |
| 292 | static int blkdev_readpage(struct file * file, struct page * page) |
| 293 | { |
| 294 | return block_read_full_page(page, blkdev_get_block); |
| 295 | } |
| 296 | |
Akinobu Mita | 447f05b | 2014-10-09 15:26:58 -0700 | [diff] [blame] | 297 | static int blkdev_readpages(struct file *file, struct address_space *mapping, |
| 298 | struct list_head *pages, unsigned nr_pages) |
| 299 | { |
| 300 | return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block); |
| 301 | } |
| 302 | |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 303 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
| 304 | loff_t pos, unsigned len, unsigned flags, |
| 305 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | { |
Christoph Hellwig | 155130a | 2010-06-04 11:29:58 +0200 | [diff] [blame] | 307 | return block_write_begin(mapping, pos, len, flags, pagep, |
| 308 | blkdev_get_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | } |
| 310 | |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 311 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
| 312 | loff_t pos, unsigned len, unsigned copied, |
| 313 | struct page *page, void *fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | { |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 315 | int ret; |
| 316 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); |
| 317 | |
| 318 | unlock_page(page); |
| 319 | page_cache_release(page); |
| 320 | |
| 321 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | /* |
| 325 | * private llseek: |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 326 | * for a block special file file_inode(file)->i_size is zero |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | * so we compute the size by hand (just as in block_read/write above) |
| 328 | */ |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 329 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | { |
| 331 | struct inode *bd_inode = file->f_mapping->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | loff_t retval; |
| 333 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 334 | mutex_lock(&bd_inode->i_mutex); |
Al Viro | 5d48f3a | 2013-06-23 21:34:45 +0400 | [diff] [blame] | 335 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 336 | mutex_unlock(&bd_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | return retval; |
| 338 | } |
| 339 | |
Josef Bacik | 02c24a8 | 2011-07-16 20:44:56 -0400 | [diff] [blame] | 340 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | { |
Anton Blanchard | b8af67e | 2010-04-23 13:18:06 -0400 | [diff] [blame] | 342 | struct inode *bd_inode = filp->f_mapping->host; |
| 343 | struct block_device *bdev = I_BDEV(bd_inode); |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 344 | int error; |
Rafael J. Wysocki | da5aa86 | 2011-08-02 02:17:48 +0200 | [diff] [blame] | 345 | |
| 346 | error = filemap_write_and_wait_range(filp->f_mapping, start, end); |
| 347 | if (error) |
| 348 | return error; |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 349 | |
Anton Blanchard | b8af67e | 2010-04-23 13:18:06 -0400 | [diff] [blame] | 350 | /* |
| 351 | * There is no need to serialise calls to blkdev_issue_flush with |
| 352 | * i_mutex and doing so causes performance issues with concurrent |
| 353 | * O_SYNC writers to a block device. |
| 354 | */ |
Christoph Hellwig | dd3932e | 2010-09-16 20:51:46 +0200 | [diff] [blame] | 355 | error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 356 | if (error == -EOPNOTSUPP) |
| 357 | error = 0; |
Anton Blanchard | b8af67e | 2010-04-23 13:18:06 -0400 | [diff] [blame] | 358 | |
Christoph Hellwig | ab0a973 | 2009-10-29 14:14:04 +0100 | [diff] [blame] | 359 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | } |
Andrew Morton | b1dd3b2 | 2010-04-06 14:35:00 -0700 | [diff] [blame] | 361 | EXPORT_SYMBOL(blkdev_fsync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | |
Matthew Wilcox | 47a191f | 2014-06-04 16:07:46 -0700 | [diff] [blame] | 363 | /** |
| 364 | * bdev_read_page() - Start reading a page from a block device |
| 365 | * @bdev: The device to read the page from |
| 366 | * @sector: The offset on the device to read the page to (need not be aligned) |
| 367 | * @page: The page to read |
| 368 | * |
| 369 | * On entry, the page should be locked. It will be unlocked when the page |
| 370 | * has been read. If the block driver implements rw_page synchronously, |
| 371 | * that will be true on exit from this function, but it need not be. |
| 372 | * |
| 373 | * Errors returned by this function are usually "soft", eg out of memory, or |
| 374 | * queue full; callers should try a different route to read this page rather |
| 375 | * than propagate an error back up the stack. |
| 376 | * |
| 377 | * Return: negative errno if an error occurs, 0 if submission was successful. |
| 378 | */ |
| 379 | int bdev_read_page(struct block_device *bdev, sector_t sector, |
| 380 | struct page *page) |
| 381 | { |
| 382 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
| 383 | if (!ops->rw_page) |
| 384 | return -EOPNOTSUPP; |
| 385 | return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ); |
| 386 | } |
| 387 | EXPORT_SYMBOL_GPL(bdev_read_page); |
| 388 | |
| 389 | /** |
| 390 | * bdev_write_page() - Start writing a page to a block device |
| 391 | * @bdev: The device to write the page to |
| 392 | * @sector: The offset on the device to write the page to (need not be aligned) |
| 393 | * @page: The page to write |
| 394 | * @wbc: The writeback_control for the write |
| 395 | * |
| 396 | * On entry, the page should be locked and not currently under writeback. |
| 397 | * On exit, if the write started successfully, the page will be unlocked and |
| 398 | * under writeback. If the write failed already (eg the driver failed to |
| 399 | * queue the page to the device), the page will still be locked. If the |
| 400 | * caller is a ->writepage implementation, it will need to unlock the page. |
| 401 | * |
| 402 | * Errors returned by this function are usually "soft", eg out of memory, or |
| 403 | * queue full; callers should try a different route to write this page rather |
| 404 | * than propagate an error back up the stack. |
| 405 | * |
| 406 | * Return: negative errno if an error occurs, 0 if submission was successful. |
| 407 | */ |
| 408 | int bdev_write_page(struct block_device *bdev, sector_t sector, |
| 409 | struct page *page, struct writeback_control *wbc) |
| 410 | { |
| 411 | int result; |
| 412 | int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE; |
| 413 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
| 414 | if (!ops->rw_page) |
| 415 | return -EOPNOTSUPP; |
| 416 | set_page_writeback(page); |
| 417 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); |
| 418 | if (result) |
| 419 | end_page_writeback(page); |
| 420 | else |
| 421 | unlock_page(page); |
| 422 | return result; |
| 423 | } |
| 424 | EXPORT_SYMBOL_GPL(bdev_write_page); |
| 425 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | /* |
| 427 | * pseudo-fs |
| 428 | */ |
| 429 | |
| 430 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 431 | static struct kmem_cache * bdev_cachep __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | |
| 433 | static struct inode *bdev_alloc_inode(struct super_block *sb) |
| 434 | { |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 435 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | if (!ei) |
| 437 | return NULL; |
| 438 | return &ei->vfs_inode; |
| 439 | } |
| 440 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 441 | static void bdev_i_callback(struct rcu_head *head) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | { |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 443 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | struct bdev_inode *bdi = BDEV_I(inode); |
| 445 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | kmem_cache_free(bdev_cachep, bdi); |
| 447 | } |
| 448 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 449 | static void bdev_destroy_inode(struct inode *inode) |
| 450 | { |
| 451 | call_rcu(&inode->i_rcu, bdev_i_callback); |
| 452 | } |
| 453 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 454 | static void init_once(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | { |
| 456 | struct bdev_inode *ei = (struct bdev_inode *) foo; |
| 457 | struct block_device *bdev = &ei->bdev; |
| 458 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 459 | memset(bdev, 0, sizeof(*bdev)); |
| 460 | mutex_init(&bdev->bd_mutex); |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 461 | INIT_LIST_HEAD(&bdev->bd_inodes); |
| 462 | INIT_LIST_HEAD(&bdev->bd_list); |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 463 | #ifdef CONFIG_SYSFS |
| 464 | INIT_LIST_HEAD(&bdev->bd_holder_disks); |
| 465 | #endif |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 466 | inode_init_once(&ei->vfs_inode); |
Takashi Sato | fcccf50 | 2009-01-09 16:40:59 -0800 | [diff] [blame] | 467 | /* Initialize mutex for freeze. */ |
| 468 | mutex_init(&bdev->bd_fsfreeze_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | } |
| 470 | |
| 471 | static inline void __bd_forget(struct inode *inode) |
| 472 | { |
| 473 | list_del_init(&inode->i_devices); |
| 474 | inode->i_bdev = NULL; |
| 475 | inode->i_mapping = &inode->i_data; |
| 476 | } |
| 477 | |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 478 | static void bdev_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | { |
| 480 | struct block_device *bdev = &BDEV_I(inode)->bdev; |
| 481 | struct list_head *p; |
Johannes Weiner | 91b0abe | 2014-04-03 14:47:49 -0700 | [diff] [blame] | 482 | truncate_inode_pages_final(&inode->i_data); |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 483 | invalidate_inode_buffers(inode); /* is it needed here? */ |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 484 | clear_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | spin_lock(&bdev_lock); |
| 486 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { |
| 487 | __bd_forget(list_entry(p, struct inode, i_devices)); |
| 488 | } |
| 489 | list_del_init(&bdev->bd_list); |
| 490 | spin_unlock(&bdev_lock); |
| 491 | } |
| 492 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 493 | static const struct super_operations bdev_sops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | .statfs = simple_statfs, |
| 495 | .alloc_inode = bdev_alloc_inode, |
| 496 | .destroy_inode = bdev_destroy_inode, |
| 497 | .drop_inode = generic_delete_inode, |
Al Viro | b57922d | 2010-06-07 14:34:48 -0400 | [diff] [blame] | 498 | .evict_inode = bdev_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | }; |
| 500 | |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 501 | static struct dentry *bd_mount(struct file_system_type *fs_type, |
| 502 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | { |
Muthu Kumar | b502bd1 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 504 | return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | } |
| 506 | |
| 507 | static struct file_system_type bd_type = { |
| 508 | .name = "bdev", |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 509 | .mount = bd_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | .kill_sb = kill_anon_super, |
| 511 | }; |
| 512 | |
Al Viro | f47ec3f | 2011-11-21 21:15:42 -0500 | [diff] [blame] | 513 | static struct super_block *blockdev_superblock __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | |
| 515 | void __init bdev_cache_init(void) |
| 516 | { |
| 517 | int err; |
Sergey Senozhatsky | ace8577 | 2012-01-10 02:43:59 +0300 | [diff] [blame] | 518 | static struct vfsmount *bd_mnt; |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 519 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
Paul Jackson | fffb60f | 2006-03-24 03:16:06 -0800 | [diff] [blame] | 521 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
| 522 | SLAB_MEM_SPREAD|SLAB_PANIC), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 523 | init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | err = register_filesystem(&bd_type); |
| 525 | if (err) |
| 526 | panic("Cannot register bdev pseudo-fs"); |
| 527 | bd_mnt = kern_mount(&bd_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | if (IS_ERR(bd_mnt)) |
| 529 | panic("Cannot create bdev pseudo-fs"); |
Sergey Senozhatsky | ace8577 | 2012-01-10 02:43:59 +0300 | [diff] [blame] | 530 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | } |
| 532 | |
| 533 | /* |
| 534 | * Most likely _very_ bad one - but then it's hardly critical for small |
| 535 | * /dev and can be fixed when somebody will need really large one. |
| 536 | * Keep in mind that it will be fed through icache hash function too. |
| 537 | */ |
| 538 | static inline unsigned long hash(dev_t dev) |
| 539 | { |
| 540 | return MAJOR(dev)+MINOR(dev); |
| 541 | } |
| 542 | |
| 543 | static int bdev_test(struct inode *inode, void *data) |
| 544 | { |
| 545 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; |
| 546 | } |
| 547 | |
| 548 | static int bdev_set(struct inode *inode, void *data) |
| 549 | { |
| 550 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; |
| 551 | return 0; |
| 552 | } |
| 553 | |
| 554 | static LIST_HEAD(all_bdevs); |
| 555 | |
| 556 | struct block_device *bdget(dev_t dev) |
| 557 | { |
| 558 | struct block_device *bdev; |
| 559 | struct inode *inode; |
| 560 | |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 561 | inode = iget5_locked(blockdev_superblock, hash(dev), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | bdev_test, bdev_set, &dev); |
| 563 | |
| 564 | if (!inode) |
| 565 | return NULL; |
| 566 | |
| 567 | bdev = &BDEV_I(inode)->bdev; |
| 568 | |
| 569 | if (inode->i_state & I_NEW) { |
| 570 | bdev->bd_contains = NULL; |
Lachlan McIlroy | 782b94c | 2011-06-30 11:01:45 +1000 | [diff] [blame] | 571 | bdev->bd_super = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | bdev->bd_inode = inode; |
| 573 | bdev->bd_block_size = (1 << inode->i_blkbits); |
| 574 | bdev->bd_part_count = 0; |
| 575 | bdev->bd_invalidated = 0; |
| 576 | inode->i_mode = S_IFBLK; |
| 577 | inode->i_rdev = dev; |
| 578 | inode->i_bdev = bdev; |
| 579 | inode->i_data.a_ops = &def_blk_aops; |
| 580 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); |
| 581 | inode->i_data.backing_dev_info = &default_backing_dev_info; |
| 582 | spin_lock(&bdev_lock); |
| 583 | list_add(&bdev->bd_list, &all_bdevs); |
| 584 | spin_unlock(&bdev_lock); |
| 585 | unlock_new_inode(inode); |
| 586 | } |
| 587 | return bdev; |
| 588 | } |
| 589 | |
| 590 | EXPORT_SYMBOL(bdget); |
| 591 | |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 592 | /** |
| 593 | * bdgrab -- Grab a reference to an already referenced block device |
| 594 | * @bdev: Block device to grab a reference to. |
| 595 | */ |
| 596 | struct block_device *bdgrab(struct block_device *bdev) |
| 597 | { |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 598 | ihold(bdev->bd_inode); |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 599 | return bdev; |
| 600 | } |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 601 | EXPORT_SYMBOL(bdgrab); |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 602 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | long nr_blockdev_pages(void) |
| 604 | { |
Matthias Kaehlcke | 203a293 | 2007-07-15 23:40:23 -0700 | [diff] [blame] | 605 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | long ret = 0; |
| 607 | spin_lock(&bdev_lock); |
Matthias Kaehlcke | 203a293 | 2007-07-15 23:40:23 -0700 | [diff] [blame] | 608 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | ret += bdev->bd_inode->i_mapping->nrpages; |
| 610 | } |
| 611 | spin_unlock(&bdev_lock); |
| 612 | return ret; |
| 613 | } |
| 614 | |
| 615 | void bdput(struct block_device *bdev) |
| 616 | { |
| 617 | iput(bdev->bd_inode); |
| 618 | } |
| 619 | |
| 620 | EXPORT_SYMBOL(bdput); |
| 621 | |
| 622 | static struct block_device *bd_acquire(struct inode *inode) |
| 623 | { |
| 624 | struct block_device *bdev; |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 625 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | spin_lock(&bdev_lock); |
| 627 | bdev = inode->i_bdev; |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 628 | if (bdev) { |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 629 | ihold(bdev->bd_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | spin_unlock(&bdev_lock); |
| 631 | return bdev; |
| 632 | } |
| 633 | spin_unlock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 634 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | bdev = bdget(inode->i_rdev); |
| 636 | if (bdev) { |
| 637 | spin_lock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 638 | if (!inode->i_bdev) { |
| 639 | /* |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 640 | * We take an additional reference to bd_inode, |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 641 | * and it's released in clear_inode() of inode. |
| 642 | * So, we can access it via ->i_mapping always |
| 643 | * without igrab(). |
| 644 | */ |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 645 | ihold(bdev->bd_inode); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 646 | inode->i_bdev = bdev; |
| 647 | inode->i_mapping = bdev->bd_inode->i_mapping; |
| 648 | list_add(&inode->i_devices, &bdev->bd_inodes); |
| 649 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | spin_unlock(&bdev_lock); |
| 651 | } |
| 652 | return bdev; |
| 653 | } |
| 654 | |
Jan Kara | a885599 | 2013-07-09 22:36:45 +0800 | [diff] [blame] | 655 | int sb_is_blkdev_sb(struct super_block *sb) |
Al Viro | f47ec3f | 2011-11-21 21:15:42 -0500 | [diff] [blame] | 656 | { |
| 657 | return sb == blockdev_superblock; |
| 658 | } |
| 659 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | /* Call when you free inode */ |
| 661 | |
| 662 | void bd_forget(struct inode *inode) |
| 663 | { |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 664 | struct block_device *bdev = NULL; |
| 665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | spin_lock(&bdev_lock); |
Yan Hong | b4ea2ea | 2013-04-30 15:26:47 -0700 | [diff] [blame] | 667 | if (!sb_is_blkdev_sb(inode->i_sb)) |
| 668 | bdev = inode->i_bdev; |
| 669 | __bd_forget(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | spin_unlock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 671 | |
| 672 | if (bdev) |
| 673 | iput(bdev->bd_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | } |
| 675 | |
Tejun Heo | 1a3cbbc | 2010-04-07 18:52:29 +0900 | [diff] [blame] | 676 | /** |
| 677 | * bd_may_claim - test whether a block device can be claimed |
| 678 | * @bdev: block device of interest |
| 679 | * @whole: whole block device containing @bdev, may equal @bdev |
| 680 | * @holder: holder trying to claim @bdev |
| 681 | * |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 682 | * Test whether @bdev can be claimed by @holder. |
Tejun Heo | 1a3cbbc | 2010-04-07 18:52:29 +0900 | [diff] [blame] | 683 | * |
| 684 | * CONTEXT: |
| 685 | * spin_lock(&bdev_lock). |
| 686 | * |
| 687 | * RETURNS: |
| 688 | * %true if @bdev can be claimed, %false otherwise. |
| 689 | */ |
| 690 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, |
| 691 | void *holder) |
| 692 | { |
| 693 | if (bdev->bd_holder == holder) |
| 694 | return true; /* already a holder */ |
| 695 | else if (bdev->bd_holder != NULL) |
| 696 | return false; /* held by someone else */ |
| 697 | else if (bdev->bd_contains == bdev) |
| 698 | return true; /* is a whole device which isn't held */ |
| 699 | |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 700 | else if (whole->bd_holder == bd_may_claim) |
Tejun Heo | 1a3cbbc | 2010-04-07 18:52:29 +0900 | [diff] [blame] | 701 | return true; /* is a partition of a device that is being partitioned */ |
| 702 | else if (whole->bd_holder != NULL) |
| 703 | return false; /* is a partition of a held device */ |
| 704 | else |
| 705 | return true; /* is a partition of an un-held device */ |
| 706 | } |
| 707 | |
| 708 | /** |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 709 | * bd_prepare_to_claim - prepare to claim a block device |
| 710 | * @bdev: block device of interest |
| 711 | * @whole: the whole device containing @bdev, may equal @bdev |
| 712 | * @holder: holder trying to claim @bdev |
| 713 | * |
| 714 | * Prepare to claim @bdev. This function fails if @bdev is already |
| 715 | * claimed by another holder and waits if another claiming is in |
| 716 | * progress. This function doesn't actually claim. On successful |
| 717 | * return, the caller has ownership of bd_claiming and bd_holder[s]. |
| 718 | * |
| 719 | * CONTEXT: |
| 720 | * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab |
| 721 | * it multiple times. |
| 722 | * |
| 723 | * RETURNS: |
| 724 | * 0 if @bdev can be claimed, -EBUSY otherwise. |
| 725 | */ |
| 726 | static int bd_prepare_to_claim(struct block_device *bdev, |
| 727 | struct block_device *whole, void *holder) |
| 728 | { |
| 729 | retry: |
| 730 | /* if someone else claimed, fail */ |
| 731 | if (!bd_may_claim(bdev, whole, holder)) |
| 732 | return -EBUSY; |
| 733 | |
Tejun Heo | e75aa85 | 2010-08-04 17:59:39 +0200 | [diff] [blame] | 734 | /* if claiming is already in progress, wait for it to finish */ |
| 735 | if (whole->bd_claiming) { |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 736 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
| 737 | DEFINE_WAIT(wait); |
| 738 | |
| 739 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); |
| 740 | spin_unlock(&bdev_lock); |
| 741 | schedule(); |
| 742 | finish_wait(wq, &wait); |
| 743 | spin_lock(&bdev_lock); |
| 744 | goto retry; |
| 745 | } |
| 746 | |
| 747 | /* yay, all mine */ |
| 748 | return 0; |
| 749 | } |
| 750 | |
| 751 | /** |
| 752 | * bd_start_claiming - start claiming a block device |
| 753 | * @bdev: block device of interest |
| 754 | * @holder: holder trying to claim @bdev |
| 755 | * |
| 756 | * @bdev is about to be opened exclusively. Check @bdev can be opened |
| 757 | * exclusively and mark that an exclusive open is in progress. Each |
| 758 | * successful call to this function must be matched with a call to |
Nick Piggin | b001836 | 2010-05-26 01:51:19 +1000 | [diff] [blame] | 759 | * either bd_finish_claiming() or bd_abort_claiming() (which do not |
| 760 | * fail). |
| 761 | * |
| 762 | * This function is used to gain exclusive access to the block device |
| 763 | * without actually causing other exclusive open attempts to fail. It |
| 764 | * should be used when the open sequence itself requires exclusive |
| 765 | * access but may subsequently fail. |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 766 | * |
| 767 | * CONTEXT: |
| 768 | * Might sleep. |
| 769 | * |
| 770 | * RETURNS: |
| 771 | * Pointer to the block device containing @bdev on success, ERR_PTR() |
| 772 | * value on failure. |
| 773 | */ |
| 774 | static struct block_device *bd_start_claiming(struct block_device *bdev, |
| 775 | void *holder) |
| 776 | { |
| 777 | struct gendisk *disk; |
| 778 | struct block_device *whole; |
| 779 | int partno, err; |
| 780 | |
| 781 | might_sleep(); |
| 782 | |
| 783 | /* |
| 784 | * @bdev might not have been initialized properly yet, look up |
| 785 | * and grab the outer block device the hard way. |
| 786 | */ |
| 787 | disk = get_gendisk(bdev->bd_dev, &partno); |
| 788 | if (!disk) |
| 789 | return ERR_PTR(-ENXIO); |
| 790 | |
Tejun Heo | d4c208b | 2011-06-13 12:45:48 +0200 | [diff] [blame] | 791 | /* |
| 792 | * Normally, @bdev should equal what's returned from bdget_disk() |
| 793 | * if partno is 0; however, some drivers (floppy) use multiple |
| 794 | * bdev's for the same physical device and @bdev may be one of the |
| 795 | * aliases. Keep @bdev if partno is 0. This means claimer |
| 796 | * tracking is broken for those devices but it has always been that |
| 797 | * way. |
| 798 | */ |
| 799 | if (partno) |
| 800 | whole = bdget_disk(disk, 0); |
| 801 | else |
| 802 | whole = bdgrab(bdev); |
| 803 | |
Nick Piggin | cf34257 | 2010-05-26 01:50:21 +1000 | [diff] [blame] | 804 | module_put(disk->fops->owner); |
Tejun Heo | 6b4517a | 2010-04-07 18:53:59 +0900 | [diff] [blame] | 805 | put_disk(disk); |
| 806 | if (!whole) |
| 807 | return ERR_PTR(-ENOMEM); |
| 808 | |
| 809 | /* prepare to claim, if successful, mark claiming in progress */ |
| 810 | spin_lock(&bdev_lock); |
| 811 | |
| 812 | err = bd_prepare_to_claim(bdev, whole, holder); |
| 813 | if (err == 0) { |
| 814 | whole->bd_claiming = holder; |
| 815 | spin_unlock(&bdev_lock); |
| 816 | return whole; |
| 817 | } else { |
| 818 | spin_unlock(&bdev_lock); |
| 819 | bdput(whole); |
| 820 | return ERR_PTR(err); |
| 821 | } |
| 822 | } |
| 823 | |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 824 | #ifdef CONFIG_SYSFS |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 825 | struct bd_holder_disk { |
| 826 | struct list_head list; |
| 827 | struct gendisk *disk; |
| 828 | int refcnt; |
| 829 | }; |
| 830 | |
| 831 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, |
| 832 | struct gendisk *disk) |
| 833 | { |
| 834 | struct bd_holder_disk *holder; |
| 835 | |
| 836 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) |
| 837 | if (holder->disk == disk) |
| 838 | return holder; |
| 839 | return NULL; |
| 840 | } |
| 841 | |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 842 | static int add_symlink(struct kobject *from, struct kobject *to) |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 843 | { |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 844 | return sysfs_create_link(from, to, kobject_name(to)); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 845 | } |
| 846 | |
| 847 | static void del_symlink(struct kobject *from, struct kobject *to) |
| 848 | { |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 849 | sysfs_remove_link(from, kobject_name(to)); |
| 850 | } |
| 851 | |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 852 | /** |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 853 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
| 854 | * @bdev: the claimed slave bdev |
| 855 | * @disk: the holding disk |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 856 | * |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 857 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
| 858 | * |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 859 | * This functions creates the following sysfs symlinks. |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 860 | * |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 861 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
| 862 | * - from "holders" directory of the @bdev to the holder @disk |
| 863 | * |
| 864 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
| 865 | * passed to bd_link_disk_holder(), then: |
| 866 | * |
| 867 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
| 868 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 |
| 869 | * |
| 870 | * The caller must have claimed @bdev before calling this function and |
| 871 | * ensure that both @bdev and @disk are valid during the creation and |
| 872 | * lifetime of these symlinks. |
| 873 | * |
| 874 | * CONTEXT: |
| 875 | * Might sleep. |
| 876 | * |
| 877 | * RETURNS: |
| 878 | * 0 on success, -errno on failure. |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 879 | */ |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 880 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 881 | { |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 882 | struct bd_holder_disk *holder; |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 883 | int ret = 0; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 884 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 885 | mutex_lock(&bdev->bd_mutex); |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 886 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 887 | WARN_ON_ONCE(!bdev->bd_holder); |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 888 | |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 889 | /* FIXME: remove the following once add_disk() handles errors */ |
| 890 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) |
| 891 | goto out_unlock; |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 892 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 893 | holder = bd_find_holder_disk(bdev, disk); |
| 894 | if (holder) { |
| 895 | holder->refcnt++; |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 896 | goto out_unlock; |
| 897 | } |
| 898 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 899 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
| 900 | if (!holder) { |
| 901 | ret = -ENOMEM; |
| 902 | goto out_unlock; |
| 903 | } |
| 904 | |
| 905 | INIT_LIST_HEAD(&holder->list); |
| 906 | holder->disk = disk; |
| 907 | holder->refcnt = 1; |
| 908 | |
| 909 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); |
| 910 | if (ret) |
| 911 | goto out_free; |
| 912 | |
| 913 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); |
| 914 | if (ret) |
| 915 | goto out_del; |
Tejun Heo | e7407d1 | 2011-02-24 09:56:32 +0100 | [diff] [blame] | 916 | /* |
| 917 | * bdev could be deleted beneath us which would implicitly destroy |
| 918 | * the holder directory. Hold on to it. |
| 919 | */ |
| 920 | kobject_get(bdev->bd_part->holder_dir); |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 921 | |
| 922 | list_add(&holder->list, &bdev->bd_holder_disks); |
| 923 | goto out_unlock; |
| 924 | |
| 925 | out_del: |
| 926 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); |
| 927 | out_free: |
| 928 | kfree(holder); |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 929 | out_unlock: |
Jun'ichi Nomura | b4cf1b7 | 2006-03-27 01:18:00 -0800 | [diff] [blame] | 930 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 931 | return ret; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 932 | } |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 933 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 934 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 935 | /** |
| 936 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() |
| 937 | * @bdev: the calimed slave bdev |
| 938 | * @disk: the holding disk |
| 939 | * |
| 940 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
| 941 | * |
| 942 | * CONTEXT: |
| 943 | * Might sleep. |
| 944 | */ |
| 945 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 946 | { |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 947 | struct bd_holder_disk *holder; |
Tejun Heo | e09b457 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 948 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 949 | mutex_lock(&bdev->bd_mutex); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 950 | |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 951 | holder = bd_find_holder_disk(bdev, disk); |
| 952 | |
| 953 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { |
| 954 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); |
| 955 | del_symlink(bdev->bd_part->holder_dir, |
| 956 | &disk_to_dev(disk)->kobj); |
Tejun Heo | e7407d1 | 2011-02-24 09:56:32 +0100 | [diff] [blame] | 957 | kobject_put(bdev->bd_part->holder_dir); |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 958 | list_del_init(&holder->list); |
| 959 | kfree(holder); |
| 960 | } |
| 961 | |
| 962 | mutex_unlock(&bdev->bd_mutex); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 963 | } |
Tejun Heo | 49731ba | 2011-01-14 18:43:57 +0100 | [diff] [blame] | 964 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 965 | #endif |
| 966 | |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 967 | /** |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 968 | * flush_disk - invalidates all buffer-cache entries on a disk |
| 969 | * |
| 970 | * @bdev: struct block device to be flushed |
Randy Dunlap | e6eb5ce | 2011-02-26 10:54:00 -0800 | [diff] [blame] | 971 | * @kill_dirty: flag to guide handling of dirty inodes |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 972 | * |
| 973 | * Invalidates all buffer-cache entries on a disk. It should be called |
| 974 | * when a disk has been changed -- either by a media change or online |
| 975 | * resize. |
| 976 | */ |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 977 | static void flush_disk(struct block_device *bdev, bool kill_dirty) |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 978 | { |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 979 | if (__invalidate_device(bdev, kill_dirty)) { |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 980 | char name[BDEVNAME_SIZE] = ""; |
| 981 | |
| 982 | if (bdev->bd_disk) |
| 983 | disk_name(bdev->bd_disk, 0, name); |
| 984 | printk(KERN_WARNING "VFS: busy inodes on changed media or " |
| 985 | "resized disk %s\n", name); |
| 986 | } |
| 987 | |
| 988 | if (!bdev->bd_disk) |
| 989 | return; |
Tejun Heo | d27769e | 2011-08-23 20:01:04 +0200 | [diff] [blame] | 990 | if (disk_part_scan_enabled(bdev->bd_disk)) |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 991 | bdev->bd_invalidated = 1; |
| 992 | } |
| 993 | |
| 994 | /** |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 995 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 996 | * @disk: struct gendisk to check |
| 997 | * @bdev: struct bdev to adjust. |
| 998 | * |
| 999 | * This routine checks to see if the bdev size does not match the disk size |
| 1000 | * and adjusts it if it differs. |
| 1001 | */ |
| 1002 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) |
| 1003 | { |
| 1004 | loff_t disk_size, bdev_size; |
| 1005 | |
| 1006 | disk_size = (loff_t)get_capacity(disk) << 9; |
| 1007 | bdev_size = i_size_read(bdev->bd_inode); |
| 1008 | if (disk_size != bdev_size) { |
| 1009 | char name[BDEVNAME_SIZE]; |
| 1010 | |
| 1011 | disk_name(disk, 0, name); |
| 1012 | printk(KERN_INFO |
| 1013 | "%s: detected capacity change from %lld to %lld\n", |
| 1014 | name, bdev_size, disk_size); |
| 1015 | i_size_write(bdev->bd_inode, disk_size); |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1016 | flush_disk(bdev, false); |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1017 | } |
| 1018 | } |
| 1019 | EXPORT_SYMBOL(check_disk_size_change); |
| 1020 | |
| 1021 | /** |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 1022 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1023 | * @disk: struct gendisk to be revalidated |
| 1024 | * |
| 1025 | * This routine is a wrapper for lower-level driver's revalidate_disk |
| 1026 | * call-backs. It is used to do common pre and post operations needed |
| 1027 | * for all revalidate_disk operations. |
| 1028 | */ |
| 1029 | int revalidate_disk(struct gendisk *disk) |
| 1030 | { |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1031 | struct block_device *bdev; |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1032 | int ret = 0; |
| 1033 | |
| 1034 | if (disk->fops->revalidate_disk) |
| 1035 | ret = disk->fops->revalidate_disk(disk); |
| 1036 | |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1037 | bdev = bdget_disk(disk, 0); |
| 1038 | if (!bdev) |
| 1039 | return ret; |
| 1040 | |
| 1041 | mutex_lock(&bdev->bd_mutex); |
| 1042 | check_disk_size_change(disk, bdev); |
MITSUNARI Shigeo | 7630b66 | 2013-02-21 16:42:01 -0800 | [diff] [blame] | 1043 | bdev->bd_invalidated = 0; |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1044 | mutex_unlock(&bdev->bd_mutex); |
| 1045 | bdput(bdev); |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1046 | return ret; |
| 1047 | } |
| 1048 | EXPORT_SYMBOL(revalidate_disk); |
| 1049 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | /* |
| 1051 | * This routine checks whether a removable media has been changed, |
| 1052 | * and invalidates all buffer-cache-entries in that case. This |
| 1053 | * is a relatively slow routine, so we have to try to minimize using |
| 1054 | * it. Thus it is called only upon a 'mount' or 'open'. This |
| 1055 | * is the best way of combining speed and utility, I think. |
| 1056 | * People changing diskettes in the middle of an operation deserve |
| 1057 | * to lose :-) |
| 1058 | */ |
| 1059 | int check_disk_change(struct block_device *bdev) |
| 1060 | { |
| 1061 | struct gendisk *disk = bdev->bd_disk; |
Alexey Dobriyan | 83d5cde | 2009-09-21 17:01:13 -0700 | [diff] [blame] | 1062 | const struct block_device_operations *bdops = disk->fops; |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1063 | unsigned int events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1064 | |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1065 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
| 1066 | DISK_EVENT_EJECT_REQUEST); |
| 1067 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | return 0; |
| 1069 | |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1070 | flush_disk(bdev, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1071 | if (bdops->revalidate_disk) |
| 1072 | bdops->revalidate_disk(bdev->bd_disk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | return 1; |
| 1074 | } |
| 1075 | |
| 1076 | EXPORT_SYMBOL(check_disk_change); |
| 1077 | |
| 1078 | void bd_set_size(struct block_device *bdev, loff_t size) |
| 1079 | { |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 1080 | unsigned bsize = bdev_logical_block_size(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | |
Guo Chao | d646a02 | 2013-02-21 15:16:42 -0800 | [diff] [blame] | 1082 | mutex_lock(&bdev->bd_inode->i_mutex); |
| 1083 | i_size_write(bdev->bd_inode, size); |
| 1084 | mutex_unlock(&bdev->bd_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | while (bsize < PAGE_CACHE_SIZE) { |
| 1086 | if (size & bsize) |
| 1087 | break; |
| 1088 | bsize <<= 1; |
| 1089 | } |
| 1090 | bdev->bd_block_size = bsize; |
| 1091 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); |
| 1092 | } |
| 1093 | EXPORT_SYMBOL(bd_set_size); |
| 1094 | |
Al Viro | 4385bab | 2013-05-05 22:11:03 -0400 | [diff] [blame] | 1095 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1096 | |
Peter Zijlstra | 6d740cd | 2007-02-20 13:58:18 -0800 | [diff] [blame] | 1097 | /* |
| 1098 | * bd_mutex locking: |
| 1099 | * |
| 1100 | * mutex_lock(part->bd_mutex) |
| 1101 | * mutex_lock_nested(whole->bd_mutex, 1) |
| 1102 | */ |
| 1103 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1104 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | struct gendisk *disk; |
Tejun Heo | 523e1d3 | 2011-10-19 14:31:07 +0200 | [diff] [blame] | 1107 | struct module *owner; |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1108 | int ret; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1109 | int partno; |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1110 | int perm = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1112 | if (mode & FMODE_READ) |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1113 | perm |= MAY_READ; |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1114 | if (mode & FMODE_WRITE) |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1115 | perm |= MAY_WRITE; |
| 1116 | /* |
| 1117 | * hooks: /n/, see "layering violations". |
| 1118 | */ |
Chris Wright | b7300b7 | 2010-08-10 18:02:55 -0700 | [diff] [blame] | 1119 | if (!for_part) { |
| 1120 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); |
| 1121 | if (ret != 0) { |
| 1122 | bdput(bdev); |
| 1123 | return ret; |
| 1124 | } |
Al Viro | 8266602 | 2008-08-01 05:32:04 -0400 | [diff] [blame] | 1125 | } |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1126 | |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1127 | restart: |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1128 | |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1129 | ret = -ENXIO; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1130 | disk = get_gendisk(bdev->bd_dev, &partno); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1131 | if (!disk) |
Arnd Bergmann | 6e9624b | 2010-08-07 18:25:34 +0200 | [diff] [blame] | 1132 | goto out; |
Tejun Heo | 523e1d3 | 2011-10-19 14:31:07 +0200 | [diff] [blame] | 1133 | owner = disk->fops->owner; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1135 | disk_block_events(disk); |
NeilBrown | 6796bf5 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1136 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | if (!bdev->bd_openers) { |
| 1138 | bdev->bd_disk = disk; |
Andi Kleen | 87192a2 | 2012-01-12 17:20:34 -0800 | [diff] [blame] | 1139 | bdev->bd_queue = disk->queue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | bdev->bd_contains = bdev; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1141 | if (!partno) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | struct backing_dev_info *bdi; |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1143 | |
| 1144 | ret = -ENXIO; |
| 1145 | bdev->bd_part = disk_get_part(disk, partno); |
| 1146 | if (!bdev->bd_part) |
| 1147 | goto out_clear; |
| 1148 | |
Tejun Heo | 1196f8b | 2011-04-21 20:54:45 +0200 | [diff] [blame] | 1149 | ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | if (disk->fops->open) { |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1151 | ret = disk->fops->open(bdev, mode); |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1152 | if (ret == -ERESTARTSYS) { |
| 1153 | /* Lost a race with 'disk' being |
| 1154 | * deleted, try again. |
| 1155 | * See md.c |
| 1156 | */ |
| 1157 | disk_put_part(bdev->bd_part); |
| 1158 | bdev->bd_part = NULL; |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1159 | bdev->bd_disk = NULL; |
Andi Kleen | 87192a2 | 2012-01-12 17:20:34 -0800 | [diff] [blame] | 1160 | bdev->bd_queue = NULL; |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1161 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1162 | disk_unblock_events(disk); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1163 | put_disk(disk); |
Tejun Heo | 523e1d3 | 2011-10-19 14:31:07 +0200 | [diff] [blame] | 1164 | module_put(owner); |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1165 | goto restart; |
| 1166 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | } |
Tejun Heo | 7e69723 | 2011-05-23 13:26:07 +0200 | [diff] [blame] | 1168 | |
Guo Chao | de33127 | 2013-02-21 15:16:43 -0800 | [diff] [blame] | 1169 | if (!ret) { |
Tejun Heo | 7e69723 | 2011-05-23 13:26:07 +0200 | [diff] [blame] | 1170 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
| 1171 | bdi = blk_get_backing_dev_info(bdev); |
Tejun Heo | 7e69723 | 2011-05-23 13:26:07 +0200 | [diff] [blame] | 1172 | bdev_inode_switch_bdi(bdev->bd_inode, bdi); |
| 1173 | } |
| 1174 | |
Tejun Heo | 1196f8b | 2011-04-21 20:54:45 +0200 | [diff] [blame] | 1175 | /* |
| 1176 | * If the device is invalidated, rescan partition |
| 1177 | * if open succeeded or failed with -ENOMEDIUM. |
| 1178 | * The latter is necessary to prevent ghost |
| 1179 | * partitions on a removed medium. |
| 1180 | */ |
Jun'ichi Nomura | fe316bf | 2012-03-02 10:38:33 +0100 | [diff] [blame] | 1181 | if (bdev->bd_invalidated) { |
| 1182 | if (!ret) |
| 1183 | rescan_partitions(disk, bdev); |
| 1184 | else if (ret == -ENOMEDIUM) |
| 1185 | invalidate_partitions(disk, bdev); |
| 1186 | } |
Tejun Heo | 1196f8b | 2011-04-21 20:54:45 +0200 | [diff] [blame] | 1187 | if (ret) |
| 1188 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | struct block_device *whole; |
| 1191 | whole = bdget_disk(disk, 0); |
| 1192 | ret = -ENOMEM; |
| 1193 | if (!whole) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1194 | goto out_clear; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1195 | BUG_ON(for_part); |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1196 | ret = __blkdev_get(whole, mode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1197 | if (ret) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1198 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1199 | bdev->bd_contains = whole; |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 1200 | bdev_inode_switch_bdi(bdev->bd_inode, |
| 1201 | whole->bd_inode->i_data.backing_dev_info); |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1202 | bdev->bd_part = disk_get_part(disk, partno); |
Tejun Heo | e71bf0d | 2008-09-03 09:03:02 +0200 | [diff] [blame] | 1203 | if (!(disk->flags & GENHD_FL_UP) || |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1204 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | ret = -ENXIO; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1206 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1207 | } |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1208 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | } |
| 1210 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | if (bdev->bd_contains == bdev) { |
Tejun Heo | 1196f8b | 2011-04-21 20:54:45 +0200 | [diff] [blame] | 1212 | ret = 0; |
| 1213 | if (bdev->bd_disk->fops->open) |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1214 | ret = bdev->bd_disk->fops->open(bdev, mode); |
Tejun Heo | 1196f8b | 2011-04-21 20:54:45 +0200 | [diff] [blame] | 1215 | /* the same as first opener case, read comment there */ |
Jun'ichi Nomura | fe316bf | 2012-03-02 10:38:33 +0100 | [diff] [blame] | 1216 | if (bdev->bd_invalidated) { |
| 1217 | if (!ret) |
| 1218 | rescan_partitions(bdev->bd_disk, bdev); |
| 1219 | else if (ret == -ENOMEDIUM) |
| 1220 | invalidate_partitions(bdev->bd_disk, bdev); |
| 1221 | } |
Tejun Heo | 1196f8b | 2011-04-21 20:54:45 +0200 | [diff] [blame] | 1222 | if (ret) |
| 1223 | goto out_unlock_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | } |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1225 | /* only one opener holds refs to the module and disk */ |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1226 | put_disk(disk); |
Tejun Heo | 523e1d3 | 2011-10-19 14:31:07 +0200 | [diff] [blame] | 1227 | module_put(owner); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | } |
| 1229 | bdev->bd_openers++; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1230 | if (for_part) |
| 1231 | bdev->bd_part_count++; |
Arjan van de Ven | c039e31 | 2006-03-23 03:00:28 -0800 | [diff] [blame] | 1232 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1233 | disk_unblock_events(disk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | return 0; |
| 1235 | |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1236 | out_clear: |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1237 | disk_put_part(bdev->bd_part); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1238 | bdev->bd_disk = NULL; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1239 | bdev->bd_part = NULL; |
Andi Kleen | 87192a2 | 2012-01-12 17:20:34 -0800 | [diff] [blame] | 1240 | bdev->bd_queue = NULL; |
Dave Chinner | a5491e0 | 2010-10-21 11:49:26 +1100 | [diff] [blame] | 1241 | bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | if (bdev != bdev->bd_contains) |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1243 | __blkdev_put(bdev->bd_contains, mode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | bdev->bd_contains = NULL; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1245 | out_unlock_bdev: |
Arjan van de Ven | c039e31 | 2006-03-23 03:00:28 -0800 | [diff] [blame] | 1246 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 69e02c5 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1247 | disk_unblock_events(disk); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1248 | put_disk(disk); |
Tejun Heo | 523e1d3 | 2011-10-19 14:31:07 +0200 | [diff] [blame] | 1249 | module_put(owner); |
Dan Carpenter | 4345cab | 2011-03-19 13:53:31 +0100 | [diff] [blame] | 1250 | out: |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1251 | bdput(bdev); |
| 1252 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | return ret; |
| 1254 | } |
| 1255 | |
Tejun Heo | d4d7762 | 2010-11-13 11:55:18 +0100 | [diff] [blame] | 1256 | /** |
| 1257 | * blkdev_get - open a block device |
| 1258 | * @bdev: block_device to open |
| 1259 | * @mode: FMODE_* mask |
| 1260 | * @holder: exclusive holder identifier |
| 1261 | * |
| 1262 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is |
| 1263 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL |
| 1264 | * @holder is invalid. Exclusive opens may nest for the same @holder. |
| 1265 | * |
| 1266 | * On success, the reference count of @bdev is unchanged. On failure, |
| 1267 | * @bdev is put. |
| 1268 | * |
| 1269 | * CONTEXT: |
| 1270 | * Might sleep. |
| 1271 | * |
| 1272 | * RETURNS: |
| 1273 | * 0 on success, -errno on failure. |
| 1274 | */ |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1275 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | { |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1277 | struct block_device *whole = NULL; |
| 1278 | int res; |
| 1279 | |
| 1280 | WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); |
| 1281 | |
| 1282 | if ((mode & FMODE_EXCL) && holder) { |
| 1283 | whole = bd_start_claiming(bdev, holder); |
| 1284 | if (IS_ERR(whole)) { |
| 1285 | bdput(bdev); |
| 1286 | return PTR_ERR(whole); |
| 1287 | } |
| 1288 | } |
| 1289 | |
| 1290 | res = __blkdev_get(bdev, mode, 0); |
| 1291 | |
| 1292 | if (whole) { |
Tejun Heo | d4dc210 | 2011-04-21 20:54:46 +0200 | [diff] [blame] | 1293 | struct gendisk *disk = whole->bd_disk; |
| 1294 | |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1295 | /* finish claiming */ |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1296 | mutex_lock(&bdev->bd_mutex); |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1297 | spin_lock(&bdev_lock); |
| 1298 | |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1299 | if (!res) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1300 | BUG_ON(!bd_may_claim(bdev, whole, holder)); |
| 1301 | /* |
| 1302 | * Note that for a whole device bd_holders |
| 1303 | * will be incremented twice, and bd_holder |
| 1304 | * will be set to bd_may_claim before being |
| 1305 | * set to holder |
| 1306 | */ |
| 1307 | whole->bd_holders++; |
| 1308 | whole->bd_holder = bd_may_claim; |
| 1309 | bdev->bd_holders++; |
| 1310 | bdev->bd_holder = holder; |
| 1311 | } |
| 1312 | |
| 1313 | /* tell others that we're done */ |
| 1314 | BUG_ON(whole->bd_claiming != holder); |
| 1315 | whole->bd_claiming = NULL; |
| 1316 | wake_up_bit(&whole->bd_claiming, 0); |
| 1317 | |
| 1318 | spin_unlock(&bdev_lock); |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1319 | |
| 1320 | /* |
Tejun Heo | d4dc210 | 2011-04-21 20:54:46 +0200 | [diff] [blame] | 1321 | * Block event polling for write claims if requested. Any |
| 1322 | * write holder makes the write_holder state stick until |
| 1323 | * all are released. This is good enough and tracking |
| 1324 | * individual writeable reference is too fragile given the |
| 1325 | * way @mode is used in blkdev_get/put(). |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1326 | */ |
Tejun Heo | 4c49ff3 | 2011-06-01 08:27:41 +0200 | [diff] [blame] | 1327 | if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && |
| 1328 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1329 | bdev->bd_write_holder = true; |
Tejun Heo | d4dc210 | 2011-04-21 20:54:46 +0200 | [diff] [blame] | 1330 | disk_block_events(disk); |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1331 | } |
| 1332 | |
| 1333 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1334 | bdput(whole); |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1335 | } |
| 1336 | |
| 1337 | return res; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1338 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | EXPORT_SYMBOL(blkdev_get); |
| 1340 | |
Tejun Heo | d4d7762 | 2010-11-13 11:55:18 +0100 | [diff] [blame] | 1341 | /** |
| 1342 | * blkdev_get_by_path - open a block device by name |
| 1343 | * @path: path to the block device to open |
| 1344 | * @mode: FMODE_* mask |
| 1345 | * @holder: exclusive holder identifier |
| 1346 | * |
| 1347 | * Open the blockdevice described by the device file at @path. @mode |
| 1348 | * and @holder are identical to blkdev_get(). |
| 1349 | * |
| 1350 | * On success, the returned block_device has reference count of one. |
| 1351 | * |
| 1352 | * CONTEXT: |
| 1353 | * Might sleep. |
| 1354 | * |
| 1355 | * RETURNS: |
| 1356 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. |
| 1357 | */ |
| 1358 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, |
| 1359 | void *holder) |
| 1360 | { |
| 1361 | struct block_device *bdev; |
| 1362 | int err; |
| 1363 | |
| 1364 | bdev = lookup_bdev(path); |
| 1365 | if (IS_ERR(bdev)) |
| 1366 | return bdev; |
| 1367 | |
| 1368 | err = blkdev_get(bdev, mode, holder); |
| 1369 | if (err) |
| 1370 | return ERR_PTR(err); |
| 1371 | |
Chuck Ebbert | e51900f | 2011-02-16 18:11:53 -0500 | [diff] [blame] | 1372 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
| 1373 | blkdev_put(bdev, mode); |
| 1374 | return ERR_PTR(-EACCES); |
| 1375 | } |
| 1376 | |
Tejun Heo | d4d7762 | 2010-11-13 11:55:18 +0100 | [diff] [blame] | 1377 | return bdev; |
| 1378 | } |
| 1379 | EXPORT_SYMBOL(blkdev_get_by_path); |
| 1380 | |
| 1381 | /** |
| 1382 | * blkdev_get_by_dev - open a block device by device number |
| 1383 | * @dev: device number of block device to open |
| 1384 | * @mode: FMODE_* mask |
| 1385 | * @holder: exclusive holder identifier |
| 1386 | * |
| 1387 | * Open the blockdevice described by device number @dev. @mode and |
| 1388 | * @holder are identical to blkdev_get(). |
| 1389 | * |
| 1390 | * Use it ONLY if you really do not have anything better - i.e. when |
| 1391 | * you are behind a truly sucky interface and all you are given is a |
| 1392 | * device number. _Never_ to be used for internal purposes. If you |
| 1393 | * ever need it - reconsider your API. |
| 1394 | * |
| 1395 | * On success, the returned block_device has reference count of one. |
| 1396 | * |
| 1397 | * CONTEXT: |
| 1398 | * Might sleep. |
| 1399 | * |
| 1400 | * RETURNS: |
| 1401 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. |
| 1402 | */ |
| 1403 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) |
| 1404 | { |
| 1405 | struct block_device *bdev; |
| 1406 | int err; |
| 1407 | |
| 1408 | bdev = bdget(dev); |
| 1409 | if (!bdev) |
| 1410 | return ERR_PTR(-ENOMEM); |
| 1411 | |
| 1412 | err = blkdev_get(bdev, mode, holder); |
| 1413 | if (err) |
| 1414 | return ERR_PTR(err); |
| 1415 | |
| 1416 | return bdev; |
| 1417 | } |
| 1418 | EXPORT_SYMBOL(blkdev_get_by_dev); |
| 1419 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | static int blkdev_open(struct inode * inode, struct file * filp) |
| 1421 | { |
| 1422 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | |
| 1424 | /* |
| 1425 | * Preserve backwards compatibility and allow large file access |
| 1426 | * even if userspace doesn't ask for it explicitly. Some mkfs |
| 1427 | * binary needs it. We might want to drop this workaround |
| 1428 | * during an unstable branch. |
| 1429 | */ |
| 1430 | filp->f_flags |= O_LARGEFILE; |
| 1431 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1432 | if (filp->f_flags & O_NDELAY) |
| 1433 | filp->f_mode |= FMODE_NDELAY; |
| 1434 | if (filp->f_flags & O_EXCL) |
| 1435 | filp->f_mode |= FMODE_EXCL; |
| 1436 | if ((filp->f_flags & O_ACCMODE) == 3) |
| 1437 | filp->f_mode |= FMODE_WRITE_IOCTL; |
| 1438 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1439 | bdev = bd_acquire(inode); |
Pavel Emelianov | 6a2aae0 | 2006-10-28 10:38:33 -0700 | [diff] [blame] | 1440 | if (bdev == NULL) |
| 1441 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1442 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1443 | filp->f_mapping = bdev->bd_inode->i_mapping; |
| 1444 | |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1445 | return blkdev_get(bdev, filp->f_mode, filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | } |
| 1447 | |
Al Viro | 4385bab | 2013-05-05 22:11:03 -0400 | [diff] [blame] | 1448 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1449 | { |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1450 | struct gendisk *disk = bdev->bd_disk; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1451 | struct block_device *victim = NULL; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1452 | |
NeilBrown | 6796bf5 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1453 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1454 | if (for_part) |
| 1455 | bdev->bd_part_count--; |
| 1456 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1457 | if (!--bdev->bd_openers) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1458 | WARN_ON_ONCE(bdev->bd_holders); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1459 | sync_blockdev(bdev); |
| 1460 | kill_bdev(bdev); |
NeilBrown | 9400775 | 2011-09-10 17:20:21 +1000 | [diff] [blame] | 1461 | /* ->release can cause the old bdi to disappear, |
| 1462 | * so must switch it out first |
| 1463 | */ |
| 1464 | bdev_inode_switch_bdi(bdev->bd_inode, |
| 1465 | &default_backing_dev_info); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1466 | } |
| 1467 | if (bdev->bd_contains == bdev) { |
| 1468 | if (disk->fops->release) |
Al Viro | db2a144 | 2013-05-05 21:52:57 -0400 | [diff] [blame] | 1469 | disk->fops->release(disk, mode); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1470 | } |
| 1471 | if (!bdev->bd_openers) { |
| 1472 | struct module *owner = disk->fops->owner; |
| 1473 | |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1474 | disk_put_part(bdev->bd_part); |
| 1475 | bdev->bd_part = NULL; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1476 | bdev->bd_disk = NULL; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1477 | if (bdev != bdev->bd_contains) |
| 1478 | victim = bdev->bd_contains; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1479 | bdev->bd_contains = NULL; |
Tejun Heo | 523e1d3 | 2011-10-19 14:31:07 +0200 | [diff] [blame] | 1480 | |
| 1481 | put_disk(disk); |
| 1482 | module_put(owner); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1483 | } |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1484 | mutex_unlock(&bdev->bd_mutex); |
| 1485 | bdput(bdev); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1486 | if (victim) |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1487 | __blkdev_put(victim, mode, 1); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1488 | } |
| 1489 | |
Al Viro | 4385bab | 2013-05-05 22:11:03 -0400 | [diff] [blame] | 1490 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1491 | { |
Tejun Heo | 85ef06d | 2011-07-01 16:17:47 +0200 | [diff] [blame] | 1492 | mutex_lock(&bdev->bd_mutex); |
| 1493 | |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1494 | if (mode & FMODE_EXCL) { |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1495 | bool bdev_free; |
| 1496 | |
| 1497 | /* |
| 1498 | * Release a claim on the device. The holder fields |
| 1499 | * are protected with bdev_lock. bd_mutex is to |
| 1500 | * synchronize disk_holder unlinking. |
| 1501 | */ |
Tejun Heo | 6a027ef | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 1502 | spin_lock(&bdev_lock); |
| 1503 | |
| 1504 | WARN_ON_ONCE(--bdev->bd_holders < 0); |
| 1505 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); |
| 1506 | |
| 1507 | /* bd_contains might point to self, check in a separate step */ |
| 1508 | if ((bdev_free = !bdev->bd_holders)) |
| 1509 | bdev->bd_holder = NULL; |
| 1510 | if (!bdev->bd_contains->bd_holders) |
| 1511 | bdev->bd_contains->bd_holder = NULL; |
| 1512 | |
| 1513 | spin_unlock(&bdev_lock); |
| 1514 | |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1515 | /* |
| 1516 | * If this was the last claim, remove holder link and |
| 1517 | * unblock evpoll if it was a write holder. |
| 1518 | */ |
Tejun Heo | 85ef06d | 2011-07-01 16:17:47 +0200 | [diff] [blame] | 1519 | if (bdev_free && bdev->bd_write_holder) { |
| 1520 | disk_unblock_events(bdev->bd_disk); |
| 1521 | bdev->bd_write_holder = false; |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1522 | } |
Tejun Heo | 6936217 | 2011-03-09 19:54:27 +0100 | [diff] [blame] | 1523 | } |
Tejun Heo | 77ea887 | 2010-12-08 20:57:37 +0100 | [diff] [blame] | 1524 | |
Tejun Heo | 85ef06d | 2011-07-01 16:17:47 +0200 | [diff] [blame] | 1525 | /* |
| 1526 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE |
| 1527 | * event. This is to ensure detection of media removal commanded |
| 1528 | * from userland - e.g. eject(1). |
| 1529 | */ |
| 1530 | disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); |
| 1531 | |
| 1532 | mutex_unlock(&bdev->bd_mutex); |
| 1533 | |
Al Viro | 4385bab | 2013-05-05 22:11:03 -0400 | [diff] [blame] | 1534 | __blkdev_put(bdev, mode, 0); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1535 | } |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1536 | EXPORT_SYMBOL(blkdev_put); |
| 1537 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1538 | static int blkdev_close(struct inode * inode, struct file * filp) |
| 1539 | { |
| 1540 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
Al Viro | 4385bab | 2013-05-05 22:11:03 -0400 | [diff] [blame] | 1541 | blkdev_put(bdev, filp->f_mode); |
| 1542 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1543 | } |
| 1544 | |
Arnd Bergmann | bb93e3a | 2005-06-23 00:10:15 -0700 | [diff] [blame] | 1545 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1546 | { |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1547 | struct block_device *bdev = I_BDEV(file->f_mapping->host); |
| 1548 | fmode_t mode = file->f_mode; |
Christoph Hellwig | fd4ce1a | 2008-11-05 14:58:42 +0100 | [diff] [blame] | 1549 | |
| 1550 | /* |
| 1551 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have |
| 1552 | * to updated it before every ioctl. |
| 1553 | */ |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1554 | if (file->f_flags & O_NDELAY) |
Christoph Hellwig | fd4ce1a | 2008-11-05 14:58:42 +0100 | [diff] [blame] | 1555 | mode |= FMODE_NDELAY; |
| 1556 | else |
| 1557 | mode &= ~FMODE_NDELAY; |
| 1558 | |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1559 | return blkdev_ioctl(bdev, mode, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1560 | } |
| 1561 | |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1562 | /* |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1563 | * Write data to the block device. Only intended for the block device itself |
| 1564 | * and the raw driver which basically is a fake block device. |
| 1565 | * |
| 1566 | * Does not take i_mutex for the write and thus is not for general purpose |
| 1567 | * use. |
| 1568 | */ |
Al Viro | 1456c0a | 2014-04-03 03:21:50 -0400 | [diff] [blame] | 1569 | ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1570 | { |
| 1571 | struct file *file = iocb->ki_filp; |
Jianpeng Ma | 53362a0 | 2012-08-02 09:50:39 +0200 | [diff] [blame] | 1572 | struct blk_plug plug; |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1573 | ssize_t ret; |
| 1574 | |
Jianpeng Ma | 53362a0 | 2012-08-02 09:50:39 +0200 | [diff] [blame] | 1575 | blk_start_plug(&plug); |
Al Viro | 1456c0a | 2014-04-03 03:21:50 -0400 | [diff] [blame] | 1576 | ret = __generic_file_write_iter(iocb, from); |
Christoph Hellwig | 02afc27 | 2013-09-04 15:04:40 +0200 | [diff] [blame] | 1577 | if (ret > 0) { |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1578 | ssize_t err; |
Al Viro | 1456c0a | 2014-04-03 03:21:50 -0400 | [diff] [blame] | 1579 | err = generic_write_sync(file, iocb->ki_pos - ret, ret); |
Dan Carpenter | 45d4f85 | 2014-04-03 14:47:17 -0700 | [diff] [blame] | 1580 | if (err < 0) |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1581 | ret = err; |
| 1582 | } |
Jianpeng Ma | 53362a0 | 2012-08-02 09:50:39 +0200 | [diff] [blame] | 1583 | blk_finish_plug(&plug); |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1584 | return ret; |
| 1585 | } |
Al Viro | 1456c0a | 2014-04-03 03:21:50 -0400 | [diff] [blame] | 1586 | EXPORT_SYMBOL_GPL(blkdev_write_iter); |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1587 | |
David Jeffery | b2de525 | 2014-09-29 10:21:10 -0400 | [diff] [blame] | 1588 | ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 684c9aa | 2012-12-07 16:48:39 -0800 | [diff] [blame] | 1589 | { |
| 1590 | struct file *file = iocb->ki_filp; |
| 1591 | struct inode *bd_inode = file->f_mapping->host; |
| 1592 | loff_t size = i_size_read(bd_inode); |
Al Viro | a886038 | 2014-04-02 20:02:21 -0400 | [diff] [blame] | 1593 | loff_t pos = iocb->ki_pos; |
Linus Torvalds | 684c9aa | 2012-12-07 16:48:39 -0800 | [diff] [blame] | 1594 | |
| 1595 | if (pos >= size) |
| 1596 | return 0; |
| 1597 | |
| 1598 | size -= pos; |
Al Viro | a886038 | 2014-04-02 20:02:21 -0400 | [diff] [blame] | 1599 | iov_iter_truncate(to, size); |
| 1600 | return generic_file_read_iter(iocb, to); |
Linus Torvalds | 684c9aa | 2012-12-07 16:48:39 -0800 | [diff] [blame] | 1601 | } |
David Jeffery | b2de525 | 2014-09-29 10:21:10 -0400 | [diff] [blame] | 1602 | EXPORT_SYMBOL_GPL(blkdev_read_iter); |
Linus Torvalds | 684c9aa | 2012-12-07 16:48:39 -0800 | [diff] [blame] | 1603 | |
Christoph Hellwig | eef9938 | 2009-08-20 17:43:41 +0200 | [diff] [blame] | 1604 | /* |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1605 | * Try to release a page associated with block device when the system |
| 1606 | * is under memory pressure. |
| 1607 | */ |
| 1608 | static int blkdev_releasepage(struct page *page, gfp_t wait) |
| 1609 | { |
| 1610 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; |
| 1611 | |
| 1612 | if (super && super->s_op->bdev_try_to_free_page) |
| 1613 | return super->s_op->bdev_try_to_free_page(super, page, wait); |
| 1614 | |
| 1615 | return try_to_free_buffers(page); |
| 1616 | } |
| 1617 | |
Adrian Bunk | 4c54ac6 | 2008-02-18 13:48:31 +0100 | [diff] [blame] | 1618 | static const struct address_space_operations def_blk_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1619 | .readpage = blkdev_readpage, |
Akinobu Mita | 447f05b | 2014-10-09 15:26:58 -0700 | [diff] [blame] | 1620 | .readpages = blkdev_readpages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | .writepage = blkdev_writepage, |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 1622 | .write_begin = blkdev_write_begin, |
| 1623 | .write_end = blkdev_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | .writepages = generic_writepages, |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1625 | .releasepage = blkdev_releasepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | .direct_IO = blkdev_direct_IO, |
Mel Gorman | b459722 | 2013-07-03 15:02:05 -0700 | [diff] [blame] | 1627 | .is_dirty_writeback = buffer_check_dirty_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1628 | }; |
| 1629 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 1630 | const struct file_operations def_blk_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1631 | .open = blkdev_open, |
| 1632 | .release = blkdev_close, |
| 1633 | .llseek = block_llseek, |
Al Viro | a886038 | 2014-04-02 20:02:21 -0400 | [diff] [blame] | 1634 | .read = new_sync_read, |
Al Viro | 1456c0a | 2014-04-03 03:21:50 -0400 | [diff] [blame] | 1635 | .write = new_sync_write, |
Al Viro | a886038 | 2014-04-02 20:02:21 -0400 | [diff] [blame] | 1636 | .read_iter = blkdev_read_iter, |
Al Viro | 1456c0a | 2014-04-03 03:21:50 -0400 | [diff] [blame] | 1637 | .write_iter = blkdev_write_iter, |
Linus Torvalds | 1e8b333 | 2012-11-29 10:49:50 -0800 | [diff] [blame] | 1638 | .mmap = generic_file_mmap, |
Andrew Morton | b1dd3b2 | 2010-04-06 14:35:00 -0700 | [diff] [blame] | 1639 | .fsync = blkdev_fsync, |
Arnd Bergmann | bb93e3a | 2005-06-23 00:10:15 -0700 | [diff] [blame] | 1640 | .unlocked_ioctl = block_ioctl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1641 | #ifdef CONFIG_COMPAT |
| 1642 | .compat_ioctl = compat_blkdev_ioctl, |
| 1643 | #endif |
Linus Torvalds | 1e8b333 | 2012-11-29 10:49:50 -0800 | [diff] [blame] | 1644 | .splice_read = generic_file_splice_read, |
Al Viro | 8d02076 | 2014-04-05 04:27:08 -0400 | [diff] [blame] | 1645 | .splice_write = iter_file_splice_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1646 | }; |
| 1647 | |
| 1648 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) |
| 1649 | { |
| 1650 | int res; |
| 1651 | mm_segment_t old_fs = get_fs(); |
| 1652 | set_fs(KERNEL_DS); |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1653 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | set_fs(old_fs); |
| 1655 | return res; |
| 1656 | } |
| 1657 | |
| 1658 | EXPORT_SYMBOL(ioctl_by_bdev); |
| 1659 | |
| 1660 | /** |
| 1661 | * lookup_bdev - lookup a struct block_device by name |
Randy Dunlap | 94e2959 | 2009-01-06 14:41:15 -0800 | [diff] [blame] | 1662 | * @pathname: special file representing the block device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1663 | * |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 1664 | * Get a reference to the blockdevice at @pathname in the current |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | * namespace if possible and return it. Return ERR_PTR(error) |
| 1666 | * otherwise. |
| 1667 | */ |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1668 | struct block_device *lookup_bdev(const char *pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1669 | { |
| 1670 | struct block_device *bdev; |
| 1671 | struct inode *inode; |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1672 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1673 | int error; |
| 1674 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1675 | if (!pathname || !*pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1676 | return ERR_PTR(-EINVAL); |
| 1677 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1678 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1679 | if (error) |
| 1680 | return ERR_PTR(error); |
| 1681 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1682 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1683 | error = -ENOTBLK; |
| 1684 | if (!S_ISBLK(inode->i_mode)) |
| 1685 | goto fail; |
| 1686 | error = -EACCES; |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1687 | if (path.mnt->mnt_flags & MNT_NODEV) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1688 | goto fail; |
| 1689 | error = -ENOMEM; |
| 1690 | bdev = bd_acquire(inode); |
| 1691 | if (!bdev) |
| 1692 | goto fail; |
| 1693 | out: |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1694 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1695 | return bdev; |
| 1696 | fail: |
| 1697 | bdev = ERR_PTR(error); |
| 1698 | goto out; |
| 1699 | } |
Al Viro | d5686b4 | 2008-08-01 05:00:11 -0400 | [diff] [blame] | 1700 | EXPORT_SYMBOL(lookup_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1701 | |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1702 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1703 | { |
| 1704 | struct super_block *sb = get_super(bdev); |
| 1705 | int res = 0; |
| 1706 | |
| 1707 | if (sb) { |
| 1708 | /* |
| 1709 | * no need to lock the super, get_super holds the |
| 1710 | * read mutex so the filesystem cannot go away |
| 1711 | * under us (->put_super runs with the write lock |
| 1712 | * hold). |
| 1713 | */ |
| 1714 | shrink_dcache_sb(sb); |
NeilBrown | 93b270f | 2011-02-24 17:25:47 +1100 | [diff] [blame] | 1715 | res = invalidate_inodes(sb, kill_dirty); |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1716 | drop_super(sb); |
| 1717 | } |
Peter Zijlstra | f98393a | 2007-05-06 14:49:54 -0700 | [diff] [blame] | 1718 | invalidate_bdev(bdev); |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1719 | return res; |
| 1720 | } |
| 1721 | EXPORT_SYMBOL(__invalidate_device); |
Jan Kara | 5c0d6b6 | 2012-07-03 16:45:31 +0200 | [diff] [blame] | 1722 | |
| 1723 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) |
| 1724 | { |
| 1725 | struct inode *inode, *old_inode = NULL; |
| 1726 | |
| 1727 | spin_lock(&inode_sb_list_lock); |
| 1728 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
| 1729 | struct address_space *mapping = inode->i_mapping; |
| 1730 | |
| 1731 | spin_lock(&inode->i_lock); |
| 1732 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || |
| 1733 | mapping->nrpages == 0) { |
| 1734 | spin_unlock(&inode->i_lock); |
| 1735 | continue; |
| 1736 | } |
| 1737 | __iget(inode); |
| 1738 | spin_unlock(&inode->i_lock); |
| 1739 | spin_unlock(&inode_sb_list_lock); |
| 1740 | /* |
| 1741 | * We hold a reference to 'inode' so it couldn't have been |
| 1742 | * removed from s_inodes list while we dropped the |
| 1743 | * inode_sb_list_lock. We cannot iput the inode now as we can |
| 1744 | * be holding the last reference and we cannot iput it under |
| 1745 | * inode_sb_list_lock. So we keep the reference and iput it |
| 1746 | * later. |
| 1747 | */ |
| 1748 | iput(old_inode); |
| 1749 | old_inode = inode; |
| 1750 | |
| 1751 | func(I_BDEV(inode), arg); |
| 1752 | |
| 1753 | spin_lock(&inode_sb_list_lock); |
| 1754 | } |
| 1755 | spin_unlock(&inode_sb_list_lock); |
| 1756 | iput(old_inode); |
| 1757 | } |