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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/smp_lock.h> |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 15 | #include <linux/device_cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/highmem.h> |
| 17 | #include <linux/blkdev.h> |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/blkpg.h> |
| 20 | #include <linux/buffer_head.h> |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 21 | #include <linux/pagevec.h> |
David Howells | 811d736 | 2006-08-29 19:06:09 +0100 | [diff] [blame] | 22 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/mpage.h> |
| 24 | #include <linux/mount.h> |
| 25 | #include <linux/uio.h> |
| 26 | #include <linux/namei.h> |
Vignesh Babu BM | 1368c4f | 2007-05-08 00:24:32 -0700 | [diff] [blame] | 27 | #include <linux/log2.h> |
Catalin Marinas | 2e1483c | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 28 | #include <linux/kmemleak.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <asm/uaccess.h> |
David Howells | 07f3f05 | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 30 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | |
| 32 | struct bdev_inode { |
| 33 | struct block_device bdev; |
| 34 | struct inode vfs_inode; |
| 35 | }; |
| 36 | |
Adrian Bunk | 4c54ac62 | 2008-02-18 13:48:31 +0100 | [diff] [blame] | 37 | static const struct address_space_operations def_blk_aops; |
| 38 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | static inline struct bdev_inode *BDEV_I(struct inode *inode) |
| 40 | { |
| 41 | return container_of(inode, struct bdev_inode, vfs_inode); |
| 42 | } |
| 43 | |
| 44 | inline struct block_device *I_BDEV(struct inode *inode) |
| 45 | { |
| 46 | return &BDEV_I(inode)->bdev; |
| 47 | } |
| 48 | |
| 49 | EXPORT_SYMBOL(I_BDEV); |
| 50 | |
| 51 | static sector_t max_block(struct block_device *bdev) |
| 52 | { |
| 53 | sector_t retval = ~((sector_t)0); |
| 54 | loff_t sz = i_size_read(bdev->bd_inode); |
| 55 | |
| 56 | if (sz) { |
| 57 | unsigned int size = block_size(bdev); |
| 58 | unsigned int sizebits = blksize_bits(size); |
| 59 | retval = (sz >> sizebits); |
| 60 | } |
| 61 | return retval; |
| 62 | } |
| 63 | |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 64 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | static void kill_bdev(struct block_device *bdev) |
| 66 | { |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 67 | if (bdev->bd_inode->i_mapping->nrpages == 0) |
| 68 | return; |
| 69 | invalidate_bh_lrus(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | truncate_inode_pages(bdev->bd_inode->i_mapping, 0); |
| 71 | } |
| 72 | |
| 73 | int set_blocksize(struct block_device *bdev, int size) |
| 74 | { |
| 75 | /* 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] | 76 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | return -EINVAL; |
| 78 | |
| 79 | /* Size cannot be smaller than the size supported by the device */ |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 80 | if (size < bdev_logical_block_size(bdev)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | return -EINVAL; |
| 82 | |
| 83 | /* Don't change the size if it is same as current */ |
| 84 | if (bdev->bd_block_size != size) { |
| 85 | sync_blockdev(bdev); |
| 86 | bdev->bd_block_size = size; |
| 87 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
| 88 | kill_bdev(bdev); |
| 89 | } |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | EXPORT_SYMBOL(set_blocksize); |
| 94 | |
| 95 | int sb_set_blocksize(struct super_block *sb, int size) |
| 96 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | if (set_blocksize(sb->s_bdev, size)) |
| 98 | return 0; |
| 99 | /* If we get here, we know size is power of two |
| 100 | * and it's value is between 512 and PAGE_SIZE */ |
| 101 | sb->s_blocksize = size; |
Coywolf Qi Hunt | 38885bd | 2006-03-24 03:18:05 -0800 | [diff] [blame] | 102 | sb->s_blocksize_bits = blksize_bits(size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | return sb->s_blocksize; |
| 104 | } |
| 105 | |
| 106 | EXPORT_SYMBOL(sb_set_blocksize); |
| 107 | |
| 108 | int sb_min_blocksize(struct super_block *sb, int size) |
| 109 | { |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 110 | int minsize = bdev_logical_block_size(sb->s_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | if (size < minsize) |
| 112 | size = minsize; |
| 113 | return sb_set_blocksize(sb, size); |
| 114 | } |
| 115 | |
| 116 | EXPORT_SYMBOL(sb_min_blocksize); |
| 117 | |
| 118 | static int |
| 119 | blkdev_get_block(struct inode *inode, sector_t iblock, |
| 120 | struct buffer_head *bh, int create) |
| 121 | { |
| 122 | if (iblock >= max_block(I_BDEV(inode))) { |
| 123 | if (create) |
| 124 | return -EIO; |
| 125 | |
| 126 | /* |
| 127 | * for reads, we're just trying to fill a partial page. |
| 128 | * return a hole, they will have to call get_block again |
| 129 | * before they can fill it, and they will get -EIO at that |
| 130 | * time |
| 131 | */ |
| 132 | return 0; |
| 133 | } |
| 134 | bh->b_bdev = I_BDEV(inode); |
| 135 | bh->b_blocknr = iblock; |
| 136 | set_buffer_mapped(bh); |
| 137 | return 0; |
| 138 | } |
| 139 | |
Andrew Morton | b2e895d | 2007-02-03 01:14:01 -0800 | [diff] [blame] | 140 | static int |
| 141 | blkdev_get_blocks(struct inode *inode, sector_t iblock, |
| 142 | struct buffer_head *bh, int create) |
| 143 | { |
| 144 | sector_t end_block = max_block(I_BDEV(inode)); |
| 145 | unsigned long max_blocks = bh->b_size >> inode->i_blkbits; |
| 146 | |
| 147 | if ((iblock + max_blocks) > end_block) { |
| 148 | max_blocks = end_block - iblock; |
| 149 | if ((long)max_blocks <= 0) { |
| 150 | if (create) |
| 151 | return -EIO; /* write fully beyond EOF */ |
| 152 | /* |
| 153 | * It is a read which is fully beyond EOF. We return |
| 154 | * a !buffer_mapped buffer |
| 155 | */ |
| 156 | max_blocks = 0; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | bh->b_bdev = I_BDEV(inode); |
| 161 | bh->b_blocknr = iblock; |
| 162 | bh->b_size = max_blocks << inode->i_blkbits; |
| 163 | if (max_blocks) |
| 164 | set_buffer_mapped(bh); |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | static ssize_t |
| 169 | blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, |
| 170 | loff_t offset, unsigned long nr_segs) |
| 171 | { |
| 172 | struct file *file = iocb->ki_filp; |
| 173 | struct inode *inode = file->f_mapping->host; |
| 174 | |
| 175 | return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode), |
| 176 | iov, offset, nr_segs, blkdev_get_blocks, NULL); |
| 177 | } |
| 178 | |
Jan Kara | 5cee581 | 2009-04-27 16:43:51 +0200 | [diff] [blame] | 179 | int __sync_blockdev(struct block_device *bdev, int wait) |
| 180 | { |
| 181 | if (!bdev) |
| 182 | return 0; |
| 183 | if (!wait) |
| 184 | return filemap_flush(bdev->bd_inode->i_mapping); |
| 185 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); |
| 186 | } |
| 187 | |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 188 | /* |
| 189 | * Write out and wait upon all the dirty data associated with a block |
| 190 | * device via its mapping. Does not take the superblock lock. |
| 191 | */ |
| 192 | int sync_blockdev(struct block_device *bdev) |
| 193 | { |
Jan Kara | 5cee581 | 2009-04-27 16:43:51 +0200 | [diff] [blame] | 194 | return __sync_blockdev(bdev, 1); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 195 | } |
| 196 | EXPORT_SYMBOL(sync_blockdev); |
| 197 | |
| 198 | /* |
| 199 | * Write out and wait upon all dirty data associated with this |
| 200 | * device. Filesystem data as well as the underlying block |
| 201 | * device. Takes the superblock lock. |
| 202 | */ |
| 203 | int fsync_bdev(struct block_device *bdev) |
| 204 | { |
| 205 | struct super_block *sb = get_super(bdev); |
| 206 | if (sb) { |
Jan Kara | 60b0680 | 2009-04-27 16:43:53 +0200 | [diff] [blame] | 207 | int res = sync_filesystem(sb); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 208 | drop_super(sb); |
| 209 | return res; |
| 210 | } |
| 211 | return sync_blockdev(bdev); |
| 212 | } |
Al Viro | 47e4491 | 2009-04-01 07:07:16 -0400 | [diff] [blame] | 213 | EXPORT_SYMBOL(fsync_bdev); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 214 | |
| 215 | /** |
| 216 | * freeze_bdev -- lock a filesystem and force it into a consistent state |
| 217 | * @bdev: blockdevice to lock |
| 218 | * |
| 219 | * This takes the block device bd_mount_sem to make sure no new mounts |
| 220 | * happen on bdev until thaw_bdev() is called. |
| 221 | * If a superblock is found on this device, we take the s_umount semaphore |
| 222 | * on it to make sure nobody unmounts until the snapshot creation is done. |
| 223 | * The reference counter (bd_fsfreeze_count) guarantees that only the last |
| 224 | * unfreeze process can unfreeze the frozen filesystem actually when multiple |
| 225 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and |
| 226 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze |
| 227 | * actually. |
| 228 | */ |
| 229 | struct super_block *freeze_bdev(struct block_device *bdev) |
| 230 | { |
| 231 | struct super_block *sb; |
| 232 | int error = 0; |
| 233 | |
| 234 | mutex_lock(&bdev->bd_fsfreeze_mutex); |
| 235 | if (bdev->bd_fsfreeze_count > 0) { |
| 236 | bdev->bd_fsfreeze_count++; |
| 237 | sb = get_super(bdev); |
| 238 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 239 | return sb; |
| 240 | } |
| 241 | bdev->bd_fsfreeze_count++; |
| 242 | |
| 243 | down(&bdev->bd_mount_sem); |
| 244 | sb = get_super(bdev); |
| 245 | if (sb && !(sb->s_flags & MS_RDONLY)) { |
| 246 | sb->s_frozen = SB_FREEZE_WRITE; |
| 247 | smp_wmb(); |
| 248 | |
Jan Kara | 60b0680 | 2009-04-27 16:43:53 +0200 | [diff] [blame] | 249 | sync_filesystem(sb); |
Nick Piggin | 585d3bc | 2009-02-25 10:44:19 +0100 | [diff] [blame] | 250 | |
| 251 | sb->s_frozen = SB_FREEZE_TRANS; |
| 252 | smp_wmb(); |
| 253 | |
| 254 | sync_blockdev(sb->s_bdev); |
| 255 | |
| 256 | if (sb->s_op->freeze_fs) { |
| 257 | error = sb->s_op->freeze_fs(sb); |
| 258 | if (error) { |
| 259 | printk(KERN_ERR |
| 260 | "VFS:Filesystem freeze failed\n"); |
| 261 | sb->s_frozen = SB_UNFROZEN; |
| 262 | drop_super(sb); |
| 263 | up(&bdev->bd_mount_sem); |
| 264 | bdev->bd_fsfreeze_count--; |
| 265 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 266 | return ERR_PTR(error); |
| 267 | } |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | sync_blockdev(bdev); |
| 272 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 273 | |
| 274 | return sb; /* thaw_bdev releases s->s_umount and bd_mount_sem */ |
| 275 | } |
| 276 | EXPORT_SYMBOL(freeze_bdev); |
| 277 | |
| 278 | /** |
| 279 | * thaw_bdev -- unlock filesystem |
| 280 | * @bdev: blockdevice to unlock |
| 281 | * @sb: associated superblock |
| 282 | * |
| 283 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). |
| 284 | */ |
| 285 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) |
| 286 | { |
| 287 | int error = 0; |
| 288 | |
| 289 | mutex_lock(&bdev->bd_fsfreeze_mutex); |
| 290 | if (!bdev->bd_fsfreeze_count) { |
| 291 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 292 | return -EINVAL; |
| 293 | } |
| 294 | |
| 295 | bdev->bd_fsfreeze_count--; |
| 296 | if (bdev->bd_fsfreeze_count > 0) { |
| 297 | if (sb) |
| 298 | drop_super(sb); |
| 299 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 300 | return 0; |
| 301 | } |
| 302 | |
| 303 | if (sb) { |
| 304 | BUG_ON(sb->s_bdev != bdev); |
| 305 | if (!(sb->s_flags & MS_RDONLY)) { |
| 306 | if (sb->s_op->unfreeze_fs) { |
| 307 | error = sb->s_op->unfreeze_fs(sb); |
| 308 | if (error) { |
| 309 | printk(KERN_ERR |
| 310 | "VFS:Filesystem thaw failed\n"); |
| 311 | sb->s_frozen = SB_FREEZE_TRANS; |
| 312 | bdev->bd_fsfreeze_count++; |
| 313 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 314 | return error; |
| 315 | } |
| 316 | } |
| 317 | sb->s_frozen = SB_UNFROZEN; |
| 318 | smp_wmb(); |
| 319 | wake_up(&sb->s_wait_unfrozen); |
| 320 | } |
| 321 | drop_super(sb); |
| 322 | } |
| 323 | |
| 324 | up(&bdev->bd_mount_sem); |
| 325 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
| 326 | return 0; |
| 327 | } |
| 328 | EXPORT_SYMBOL(thaw_bdev); |
| 329 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
| 331 | { |
| 332 | return block_write_full_page(page, blkdev_get_block, wbc); |
| 333 | } |
| 334 | |
| 335 | static int blkdev_readpage(struct file * file, struct page * page) |
| 336 | { |
| 337 | return block_read_full_page(page, blkdev_get_block); |
| 338 | } |
| 339 | |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 340 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
| 341 | loff_t pos, unsigned len, unsigned flags, |
| 342 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | { |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 344 | *pagep = NULL; |
| 345 | return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
| 346 | blkdev_get_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | } |
| 348 | |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 349 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
| 350 | loff_t pos, unsigned len, unsigned copied, |
| 351 | struct page *page, void *fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | { |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 353 | int ret; |
| 354 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); |
| 355 | |
| 356 | unlock_page(page); |
| 357 | page_cache_release(page); |
| 358 | |
| 359 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | } |
| 361 | |
| 362 | /* |
| 363 | * private llseek: |
Josef "Jeff" Sipek | 0f7fc9e4 | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 364 | * for a block special file file->f_path.dentry->d_inode->i_size is zero |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | * so we compute the size by hand (just as in block_read/write above) |
| 366 | */ |
| 367 | static loff_t block_llseek(struct file *file, loff_t offset, int origin) |
| 368 | { |
| 369 | struct inode *bd_inode = file->f_mapping->host; |
| 370 | loff_t size; |
| 371 | loff_t retval; |
| 372 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 373 | mutex_lock(&bd_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | size = i_size_read(bd_inode); |
| 375 | |
| 376 | switch (origin) { |
| 377 | case 2: |
| 378 | offset += size; |
| 379 | break; |
| 380 | case 1: |
| 381 | offset += file->f_pos; |
| 382 | } |
| 383 | retval = -EINVAL; |
| 384 | if (offset >= 0 && offset <= size) { |
| 385 | if (offset != file->f_pos) { |
| 386 | file->f_pos = offset; |
| 387 | } |
| 388 | retval = offset; |
| 389 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 390 | mutex_unlock(&bd_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | return retval; |
| 392 | } |
| 393 | |
| 394 | /* |
| 395 | * Filp is never NULL; the only case when ->fsync() is called with |
| 396 | * NULL first argument is nfsd_sync_dir() and that's not a directory. |
| 397 | */ |
| 398 | |
| 399 | static int block_fsync(struct file *filp, struct dentry *dentry, int datasync) |
| 400 | { |
| 401 | return sync_blockdev(I_BDEV(filp->f_mapping->host)); |
| 402 | } |
| 403 | |
| 404 | /* |
| 405 | * pseudo-fs |
| 406 | */ |
| 407 | |
| 408 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 409 | static struct kmem_cache * bdev_cachep __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | |
| 411 | static struct inode *bdev_alloc_inode(struct super_block *sb) |
| 412 | { |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 413 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | if (!ei) |
| 415 | return NULL; |
| 416 | return &ei->vfs_inode; |
| 417 | } |
| 418 | |
| 419 | static void bdev_destroy_inode(struct inode *inode) |
| 420 | { |
| 421 | struct bdev_inode *bdi = BDEV_I(inode); |
| 422 | |
| 423 | bdi->bdev.bd_inode_backing_dev_info = NULL; |
| 424 | kmem_cache_free(bdev_cachep, bdi); |
| 425 | } |
| 426 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 427 | static void init_once(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | { |
| 429 | struct bdev_inode *ei = (struct bdev_inode *) foo; |
| 430 | struct block_device *bdev = &ei->bdev; |
| 431 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 432 | memset(bdev, 0, sizeof(*bdev)); |
| 433 | mutex_init(&bdev->bd_mutex); |
| 434 | sema_init(&bdev->bd_mount_sem, 1); |
| 435 | INIT_LIST_HEAD(&bdev->bd_inodes); |
| 436 | INIT_LIST_HEAD(&bdev->bd_list); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 437 | #ifdef CONFIG_SYSFS |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 438 | INIT_LIST_HEAD(&bdev->bd_holder_list); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 439 | #endif |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 440 | inode_init_once(&ei->vfs_inode); |
Takashi Sato | fcccf50 | 2009-01-09 16:40:59 -0800 | [diff] [blame] | 441 | /* Initialize mutex for freeze. */ |
| 442 | mutex_init(&bdev->bd_fsfreeze_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | } |
| 444 | |
| 445 | static inline void __bd_forget(struct inode *inode) |
| 446 | { |
| 447 | list_del_init(&inode->i_devices); |
| 448 | inode->i_bdev = NULL; |
| 449 | inode->i_mapping = &inode->i_data; |
| 450 | } |
| 451 | |
| 452 | static void bdev_clear_inode(struct inode *inode) |
| 453 | { |
| 454 | struct block_device *bdev = &BDEV_I(inode)->bdev; |
| 455 | struct list_head *p; |
| 456 | spin_lock(&bdev_lock); |
| 457 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { |
| 458 | __bd_forget(list_entry(p, struct inode, i_devices)); |
| 459 | } |
| 460 | list_del_init(&bdev->bd_list); |
| 461 | spin_unlock(&bdev_lock); |
| 462 | } |
| 463 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 464 | static const struct super_operations bdev_sops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | .statfs = simple_statfs, |
| 466 | .alloc_inode = bdev_alloc_inode, |
| 467 | .destroy_inode = bdev_destroy_inode, |
| 468 | .drop_inode = generic_delete_inode, |
| 469 | .clear_inode = bdev_clear_inode, |
| 470 | }; |
| 471 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 472 | static int bd_get_sb(struct file_system_type *fs_type, |
| 473 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 475 | return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | } |
| 477 | |
| 478 | static struct file_system_type bd_type = { |
| 479 | .name = "bdev", |
| 480 | .get_sb = bd_get_sb, |
| 481 | .kill_sb = kill_anon_super, |
| 482 | }; |
| 483 | |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 484 | struct super_block *blockdev_superblock __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | |
| 486 | void __init bdev_cache_init(void) |
| 487 | { |
| 488 | int err; |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 489 | struct vfsmount *bd_mnt; |
| 490 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
Paul Jackson | fffb60f | 2006-03-24 03:16:06 -0800 | [diff] [blame] | 492 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
| 493 | SLAB_MEM_SPREAD|SLAB_PANIC), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 494 | init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | err = register_filesystem(&bd_type); |
| 496 | if (err) |
| 497 | panic("Cannot register bdev pseudo-fs"); |
| 498 | bd_mnt = kern_mount(&bd_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | if (IS_ERR(bd_mnt)) |
| 500 | panic("Cannot create bdev pseudo-fs"); |
Catalin Marinas | 2e1483c | 2009-06-11 13:24:13 +0100 | [diff] [blame] | 501 | /* |
| 502 | * This vfsmount structure is only used to obtain the |
| 503 | * blockdev_superblock, so tell kmemleak not to report it. |
| 504 | */ |
| 505 | kmemleak_not_leak(bd_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
| 507 | } |
| 508 | |
| 509 | /* |
| 510 | * Most likely _very_ bad one - but then it's hardly critical for small |
| 511 | * /dev and can be fixed when somebody will need really large one. |
| 512 | * Keep in mind that it will be fed through icache hash function too. |
| 513 | */ |
| 514 | static inline unsigned long hash(dev_t dev) |
| 515 | { |
| 516 | return MAJOR(dev)+MINOR(dev); |
| 517 | } |
| 518 | |
| 519 | static int bdev_test(struct inode *inode, void *data) |
| 520 | { |
| 521 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; |
| 522 | } |
| 523 | |
| 524 | static int bdev_set(struct inode *inode, void *data) |
| 525 | { |
| 526 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; |
| 527 | return 0; |
| 528 | } |
| 529 | |
| 530 | static LIST_HEAD(all_bdevs); |
| 531 | |
| 532 | struct block_device *bdget(dev_t dev) |
| 533 | { |
| 534 | struct block_device *bdev; |
| 535 | struct inode *inode; |
| 536 | |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 537 | inode = iget5_locked(blockdev_superblock, hash(dev), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | bdev_test, bdev_set, &dev); |
| 539 | |
| 540 | if (!inode) |
| 541 | return NULL; |
| 542 | |
| 543 | bdev = &BDEV_I(inode)->bdev; |
| 544 | |
| 545 | if (inode->i_state & I_NEW) { |
| 546 | bdev->bd_contains = NULL; |
| 547 | bdev->bd_inode = inode; |
| 548 | bdev->bd_block_size = (1 << inode->i_blkbits); |
| 549 | bdev->bd_part_count = 0; |
| 550 | bdev->bd_invalidated = 0; |
| 551 | inode->i_mode = S_IFBLK; |
| 552 | inode->i_rdev = dev; |
| 553 | inode->i_bdev = bdev; |
| 554 | inode->i_data.a_ops = &def_blk_aops; |
| 555 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); |
| 556 | inode->i_data.backing_dev_info = &default_backing_dev_info; |
| 557 | spin_lock(&bdev_lock); |
| 558 | list_add(&bdev->bd_list, &all_bdevs); |
| 559 | spin_unlock(&bdev_lock); |
| 560 | unlock_new_inode(inode); |
| 561 | } |
| 562 | return bdev; |
| 563 | } |
| 564 | |
| 565 | EXPORT_SYMBOL(bdget); |
| 566 | |
| 567 | long nr_blockdev_pages(void) |
| 568 | { |
Matthias Kaehlcke | 203a293 | 2007-07-15 23:40:23 -0700 | [diff] [blame] | 569 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | long ret = 0; |
| 571 | spin_lock(&bdev_lock); |
Matthias Kaehlcke | 203a293 | 2007-07-15 23:40:23 -0700 | [diff] [blame] | 572 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | ret += bdev->bd_inode->i_mapping->nrpages; |
| 574 | } |
| 575 | spin_unlock(&bdev_lock); |
| 576 | return ret; |
| 577 | } |
| 578 | |
| 579 | void bdput(struct block_device *bdev) |
| 580 | { |
| 581 | iput(bdev->bd_inode); |
| 582 | } |
| 583 | |
| 584 | EXPORT_SYMBOL(bdput); |
| 585 | |
| 586 | static struct block_device *bd_acquire(struct inode *inode) |
| 587 | { |
| 588 | struct block_device *bdev; |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 589 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | spin_lock(&bdev_lock); |
| 591 | bdev = inode->i_bdev; |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 592 | if (bdev) { |
| 593 | atomic_inc(&bdev->bd_inode->i_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | spin_unlock(&bdev_lock); |
| 595 | return bdev; |
| 596 | } |
| 597 | spin_unlock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 598 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | bdev = bdget(inode->i_rdev); |
| 600 | if (bdev) { |
| 601 | spin_lock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 602 | if (!inode->i_bdev) { |
| 603 | /* |
| 604 | * We take an additional bd_inode->i_count for inode, |
| 605 | * and it's released in clear_inode() of inode. |
| 606 | * So, we can access it via ->i_mapping always |
| 607 | * without igrab(). |
| 608 | */ |
| 609 | atomic_inc(&bdev->bd_inode->i_count); |
| 610 | inode->i_bdev = bdev; |
| 611 | inode->i_mapping = bdev->bd_inode->i_mapping; |
| 612 | list_add(&inode->i_devices, &bdev->bd_inodes); |
| 613 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | spin_unlock(&bdev_lock); |
| 615 | } |
| 616 | return bdev; |
| 617 | } |
| 618 | |
| 619 | /* Call when you free inode */ |
| 620 | |
| 621 | void bd_forget(struct inode *inode) |
| 622 | { |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 623 | struct block_device *bdev = NULL; |
| 624 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | spin_lock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 626 | if (inode->i_bdev) { |
Denis ChengRq | c2acf7b | 2008-12-01 14:34:56 -0800 | [diff] [blame] | 627 | if (!sb_is_blkdev_sb(inode->i_sb)) |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 628 | bdev = inode->i_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | __bd_forget(inode); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 630 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | spin_unlock(&bdev_lock); |
OGAWA Hirofumi | 09d967c | 2006-06-22 14:47:21 -0700 | [diff] [blame] | 632 | |
| 633 | if (bdev) |
| 634 | iput(bdev->bd_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | } |
| 636 | |
| 637 | int bd_claim(struct block_device *bdev, void *holder) |
| 638 | { |
| 639 | int res; |
| 640 | spin_lock(&bdev_lock); |
| 641 | |
| 642 | /* first decide result */ |
| 643 | if (bdev->bd_holder == holder) |
| 644 | res = 0; /* already a holder */ |
| 645 | else if (bdev->bd_holder != NULL) |
| 646 | res = -EBUSY; /* held by someone else */ |
| 647 | else if (bdev->bd_contains == bdev) |
| 648 | res = 0; /* is a whole device which isn't held */ |
| 649 | |
| 650 | else if (bdev->bd_contains->bd_holder == bd_claim) |
| 651 | res = 0; /* is a partition of a device that is being partitioned */ |
| 652 | else if (bdev->bd_contains->bd_holder != NULL) |
| 653 | res = -EBUSY; /* is a partition of a held device */ |
| 654 | else |
| 655 | res = 0; /* is a partition of an un-held device */ |
| 656 | |
| 657 | /* now impose change */ |
| 658 | if (res==0) { |
| 659 | /* note that for a whole device bd_holders |
| 660 | * will be incremented twice, and bd_holder will |
| 661 | * be set to bd_claim before being set to holder |
| 662 | */ |
| 663 | bdev->bd_contains->bd_holders ++; |
| 664 | bdev->bd_contains->bd_holder = bd_claim; |
| 665 | bdev->bd_holders++; |
| 666 | bdev->bd_holder = holder; |
| 667 | } |
| 668 | spin_unlock(&bdev_lock); |
| 669 | return res; |
| 670 | } |
| 671 | |
| 672 | EXPORT_SYMBOL(bd_claim); |
| 673 | |
| 674 | void bd_release(struct block_device *bdev) |
| 675 | { |
| 676 | spin_lock(&bdev_lock); |
| 677 | if (!--bdev->bd_contains->bd_holders) |
| 678 | bdev->bd_contains->bd_holder = NULL; |
| 679 | if (!--bdev->bd_holders) |
| 680 | bdev->bd_holder = NULL; |
| 681 | spin_unlock(&bdev_lock); |
| 682 | } |
| 683 | |
| 684 | EXPORT_SYMBOL(bd_release); |
| 685 | |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 686 | #ifdef CONFIG_SYSFS |
| 687 | /* |
| 688 | * Functions for bd_claim_by_kobject / bd_release_from_kobject |
| 689 | * |
| 690 | * If a kobject is passed to bd_claim_by_kobject() |
| 691 | * and the kobject has a parent directory, |
| 692 | * following symlinks are created: |
| 693 | * o from the kobject to the claimed bdev |
| 694 | * o from "holders" directory of the bdev to the parent of the kobject |
| 695 | * bd_release_from_kobject() removes these symlinks. |
| 696 | * |
| 697 | * Example: |
| 698 | * If /dev/dm-0 maps to /dev/sda, kobject corresponding to |
| 699 | * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then: |
| 700 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
| 701 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 |
| 702 | */ |
| 703 | |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 704 | static int add_symlink(struct kobject *from, struct kobject *to) |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 705 | { |
| 706 | if (!from || !to) |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 707 | return 0; |
| 708 | return sysfs_create_link(from, to, kobject_name(to)); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 709 | } |
| 710 | |
| 711 | static void del_symlink(struct kobject *from, struct kobject *to) |
| 712 | { |
| 713 | if (!from || !to) |
| 714 | return; |
| 715 | sysfs_remove_link(from, kobject_name(to)); |
| 716 | } |
| 717 | |
| 718 | /* |
| 719 | * 'struct bd_holder' contains pointers to kobjects symlinked by |
| 720 | * bd_claim_by_kobject. |
| 721 | * It's connected to bd_holder_list which is protected by bdev->bd_sem. |
| 722 | */ |
| 723 | struct bd_holder { |
| 724 | struct list_head list; /* chain of holders of the bdev */ |
| 725 | int count; /* references from the holder */ |
| 726 | struct kobject *sdir; /* holder object, e.g. "/block/dm-0/slaves" */ |
| 727 | struct kobject *hdev; /* e.g. "/block/dm-0" */ |
| 728 | struct kobject *hdir; /* e.g. "/block/sda/holders" */ |
| 729 | struct kobject *sdev; /* e.g. "/block/sda" */ |
| 730 | }; |
| 731 | |
| 732 | /* |
| 733 | * Get references of related kobjects at once. |
| 734 | * Returns 1 on success. 0 on failure. |
| 735 | * |
| 736 | * Should call bd_holder_release_dirs() after successful use. |
| 737 | */ |
| 738 | static int bd_holder_grab_dirs(struct block_device *bdev, |
| 739 | struct bd_holder *bo) |
| 740 | { |
| 741 | if (!bdev || !bo) |
| 742 | return 0; |
| 743 | |
| 744 | bo->sdir = kobject_get(bo->sdir); |
| 745 | if (!bo->sdir) |
| 746 | return 0; |
| 747 | |
| 748 | bo->hdev = kobject_get(bo->sdir->parent); |
| 749 | if (!bo->hdev) |
| 750 | goto fail_put_sdir; |
| 751 | |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 752 | bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 753 | if (!bo->sdev) |
| 754 | goto fail_put_hdev; |
| 755 | |
Tejun Heo | 4c46501 | 2008-08-25 19:56:11 +0900 | [diff] [blame] | 756 | bo->hdir = kobject_get(bdev->bd_part->holder_dir); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 757 | if (!bo->hdir) |
| 758 | goto fail_put_sdev; |
| 759 | |
| 760 | return 1; |
| 761 | |
| 762 | fail_put_sdev: |
| 763 | kobject_put(bo->sdev); |
| 764 | fail_put_hdev: |
| 765 | kobject_put(bo->hdev); |
| 766 | fail_put_sdir: |
| 767 | kobject_put(bo->sdir); |
| 768 | |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | /* Put references of related kobjects at once. */ |
| 773 | static void bd_holder_release_dirs(struct bd_holder *bo) |
| 774 | { |
| 775 | kobject_put(bo->hdir); |
| 776 | kobject_put(bo->sdev); |
| 777 | kobject_put(bo->hdev); |
| 778 | kobject_put(bo->sdir); |
| 779 | } |
| 780 | |
| 781 | static struct bd_holder *alloc_bd_holder(struct kobject *kobj) |
| 782 | { |
| 783 | struct bd_holder *bo; |
| 784 | |
| 785 | bo = kzalloc(sizeof(*bo), GFP_KERNEL); |
| 786 | if (!bo) |
| 787 | return NULL; |
| 788 | |
| 789 | bo->count = 1; |
| 790 | bo->sdir = kobj; |
| 791 | |
| 792 | return bo; |
| 793 | } |
| 794 | |
| 795 | static void free_bd_holder(struct bd_holder *bo) |
| 796 | { |
| 797 | kfree(bo); |
| 798 | } |
| 799 | |
| 800 | /** |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 801 | * find_bd_holder - find matching struct bd_holder from the block device |
| 802 | * |
| 803 | * @bdev: struct block device to be searched |
| 804 | * @bo: target struct bd_holder |
| 805 | * |
| 806 | * Returns matching entry with @bo in @bdev->bd_holder_list. |
| 807 | * If found, increment the reference count and return the pointer. |
| 808 | * If not found, returns NULL. |
| 809 | */ |
Andrew Morton | 36a561d | 2006-10-30 22:07:03 -0800 | [diff] [blame] | 810 | static struct bd_holder *find_bd_holder(struct block_device *bdev, |
| 811 | struct bd_holder *bo) |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 812 | { |
| 813 | struct bd_holder *tmp; |
| 814 | |
| 815 | list_for_each_entry(tmp, &bdev->bd_holder_list, list) |
| 816 | if (tmp->sdir == bo->sdir) { |
| 817 | tmp->count++; |
| 818 | return tmp; |
| 819 | } |
| 820 | |
| 821 | return NULL; |
| 822 | } |
| 823 | |
| 824 | /** |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 825 | * add_bd_holder - create sysfs symlinks for bd_claim() relationship |
| 826 | * |
| 827 | * @bdev: block device to be bd_claimed |
| 828 | * @bo: preallocated and initialized by alloc_bd_holder() |
| 829 | * |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 830 | * Add @bo to @bdev->bd_holder_list, create symlinks. |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 831 | * |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 832 | * Returns 0 if symlinks are created. |
| 833 | * Returns -ve if something fails. |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 834 | */ |
| 835 | static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo) |
| 836 | { |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 837 | int err; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 838 | |
| 839 | if (!bo) |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 840 | return -EINVAL; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 841 | |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 842 | if (!bd_holder_grab_dirs(bdev, bo)) |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 843 | return -EBUSY; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 844 | |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 845 | err = add_symlink(bo->sdir, bo->sdev); |
| 846 | if (err) |
| 847 | return err; |
| 848 | |
| 849 | err = add_symlink(bo->hdir, bo->hdev); |
| 850 | if (err) { |
| 851 | del_symlink(bo->sdir, bo->sdev); |
| 852 | return err; |
Andrew Morton | 4d7dd8fd | 2006-09-29 01:58:56 -0700 | [diff] [blame] | 853 | } |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 854 | |
| 855 | list_add_tail(&bo->list, &bdev->bd_holder_list); |
| 856 | return 0; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 857 | } |
| 858 | |
| 859 | /** |
| 860 | * del_bd_holder - delete sysfs symlinks for bd_claim() relationship |
| 861 | * |
| 862 | * @bdev: block device to be bd_claimed |
| 863 | * @kobj: holder's kobject |
| 864 | * |
| 865 | * If there is matching entry with @kobj in @bdev->bd_holder_list |
| 866 | * and no other bd_claim() from the same kobject, |
| 867 | * remove the struct bd_holder from the list, delete symlinks for it. |
| 868 | * |
| 869 | * Returns a pointer to the struct bd_holder when it's removed from the list |
| 870 | * and ready to be freed. |
| 871 | * Returns NULL if matching claim isn't found or there is other bd_claim() |
| 872 | * by the same kobject. |
| 873 | */ |
| 874 | static struct bd_holder *del_bd_holder(struct block_device *bdev, |
| 875 | struct kobject *kobj) |
| 876 | { |
| 877 | struct bd_holder *bo; |
| 878 | |
| 879 | list_for_each_entry(bo, &bdev->bd_holder_list, list) { |
| 880 | if (bo->sdir == kobj) { |
| 881 | bo->count--; |
| 882 | BUG_ON(bo->count < 0); |
| 883 | if (!bo->count) { |
| 884 | list_del(&bo->list); |
| 885 | del_symlink(bo->sdir, bo->sdev); |
| 886 | del_symlink(bo->hdir, bo->hdev); |
| 887 | bd_holder_release_dirs(bo); |
| 888 | return bo; |
| 889 | } |
| 890 | break; |
| 891 | } |
| 892 | } |
| 893 | |
| 894 | return NULL; |
| 895 | } |
| 896 | |
| 897 | /** |
| 898 | * bd_claim_by_kobject - bd_claim() with additional kobject signature |
| 899 | * |
| 900 | * @bdev: block device to be claimed |
| 901 | * @holder: holder's signature |
| 902 | * @kobj: holder's kobject |
| 903 | * |
| 904 | * Do bd_claim() and if it succeeds, create sysfs symlinks between |
| 905 | * the bdev and the holder's kobject. |
| 906 | * Use bd_release_from_kobject() when relesing the claimed bdev. |
| 907 | * |
| 908 | * Returns 0 on success. (same as bd_claim()) |
| 909 | * Returns errno on failure. |
| 910 | */ |
| 911 | static int bd_claim_by_kobject(struct block_device *bdev, void *holder, |
| 912 | struct kobject *kobj) |
| 913 | { |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 914 | int err; |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 915 | struct bd_holder *bo, *found; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 916 | |
| 917 | if (!kobj) |
| 918 | return -EINVAL; |
| 919 | |
| 920 | bo = alloc_bd_holder(kobj); |
| 921 | if (!bo) |
| 922 | return -ENOMEM; |
| 923 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 924 | mutex_lock(&bdev->bd_mutex); |
Jun'ichi Nomura | df6c0cd | 2006-10-30 16:23:56 -0500 | [diff] [blame] | 925 | |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 926 | err = bd_claim(bdev, holder); |
| 927 | if (err) |
Andrew Morton | 4210df2 | 2007-07-15 23:41:28 -0700 | [diff] [blame] | 928 | goto fail; |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 929 | |
| 930 | found = find_bd_holder(bdev, bo); |
| 931 | if (found) |
Andrew Morton | 4210df2 | 2007-07-15 23:41:28 -0700 | [diff] [blame] | 932 | goto fail; |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 933 | |
| 934 | err = add_bd_holder(bdev, bo); |
| 935 | if (err) |
| 936 | bd_release(bdev); |
Andrew Morton | 4210df2 | 2007-07-15 23:41:28 -0700 | [diff] [blame] | 937 | else |
| 938 | bo = NULL; |
| 939 | fail: |
Jun'ichi Nomura | b4cf1b7 | 2006-03-27 01:18:00 -0800 | [diff] [blame] | 940 | mutex_unlock(&bdev->bd_mutex); |
Andrew Morton | 4210df2 | 2007-07-15 23:41:28 -0700 | [diff] [blame] | 941 | free_bd_holder(bo); |
Johannes Weiner | 4e91672 | 2007-07-15 23:41:25 -0700 | [diff] [blame] | 942 | return err; |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 943 | } |
| 944 | |
| 945 | /** |
| 946 | * bd_release_from_kobject - bd_release() with additional kobject signature |
| 947 | * |
| 948 | * @bdev: block device to be released |
| 949 | * @kobj: holder's kobject |
| 950 | * |
| 951 | * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject(). |
| 952 | */ |
| 953 | static void bd_release_from_kobject(struct block_device *bdev, |
| 954 | struct kobject *kobj) |
| 955 | { |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 956 | if (!kobj) |
| 957 | return; |
| 958 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 959 | mutex_lock(&bdev->bd_mutex); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 960 | bd_release(bdev); |
Andrew Morton | 4210df2 | 2007-07-15 23:41:28 -0700 | [diff] [blame] | 961 | free_bd_holder(del_bd_holder(bdev, kobj)); |
Jun'ichi Nomura | b4cf1b7 | 2006-03-27 01:18:00 -0800 | [diff] [blame] | 962 | mutex_unlock(&bdev->bd_mutex); |
Jun'ichi Nomura | 641dc63 | 2006-03-27 01:17:57 -0800 | [diff] [blame] | 963 | } |
| 964 | |
| 965 | /** |
| 966 | * bd_claim_by_disk - wrapper function for bd_claim_by_kobject() |
| 967 | * |
| 968 | * @bdev: block device to be claimed |
| 969 | * @holder: holder's signature |
| 970 | * @disk: holder's gendisk |
| 971 | * |
| 972 | * Call bd_claim_by_kobject() with getting @disk->slave_dir. |
| 973 | */ |
| 974 | int bd_claim_by_disk(struct block_device *bdev, void *holder, |
| 975 | struct gendisk *disk) |
| 976 | { |
| 977 | return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir)); |
| 978 | } |
| 979 | EXPORT_SYMBOL_GPL(bd_claim_by_disk); |
| 980 | |
| 981 | /** |
| 982 | * bd_release_from_disk - wrapper function for bd_release_from_kobject() |
| 983 | * |
| 984 | * @bdev: block device to be claimed |
| 985 | * @disk: holder's gendisk |
| 986 | * |
| 987 | * Call bd_release_from_kobject() and put @disk->slave_dir. |
| 988 | */ |
| 989 | void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk) |
| 990 | { |
| 991 | bd_release_from_kobject(bdev, disk->slave_dir); |
| 992 | kobject_put(disk->slave_dir); |
| 993 | } |
| 994 | EXPORT_SYMBOL_GPL(bd_release_from_disk); |
| 995 | #endif |
| 996 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | /* |
| 998 | * Tries to open block device by device number. Use it ONLY if you |
| 999 | * really do not have anything better - i.e. when you are behind a |
| 1000 | * truly sucky interface and all you are given is a device number. _Never_ |
| 1001 | * to be used for internal purposes. If you ever need it - reconsider |
| 1002 | * your API. |
| 1003 | */ |
Al Viro | aeb5d72 | 2008-09-02 15:28:45 -0400 | [diff] [blame] | 1004 | struct block_device *open_by_devnum(dev_t dev, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | { |
| 1006 | struct block_device *bdev = bdget(dev); |
| 1007 | int err = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | if (bdev) |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1009 | err = blkdev_get(bdev, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | return err ? ERR_PTR(err) : bdev; |
| 1011 | } |
| 1012 | |
| 1013 | EXPORT_SYMBOL(open_by_devnum); |
| 1014 | |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1015 | /** |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 1016 | * flush_disk - invalidates all buffer-cache entries on a disk |
| 1017 | * |
| 1018 | * @bdev: struct block device to be flushed |
| 1019 | * |
| 1020 | * Invalidates all buffer-cache entries on a disk. It should be called |
| 1021 | * when a disk has been changed -- either by a media change or online |
| 1022 | * resize. |
| 1023 | */ |
| 1024 | static void flush_disk(struct block_device *bdev) |
| 1025 | { |
| 1026 | if (__invalidate_device(bdev)) { |
| 1027 | char name[BDEVNAME_SIZE] = ""; |
| 1028 | |
| 1029 | if (bdev->bd_disk) |
| 1030 | disk_name(bdev->bd_disk, 0, name); |
| 1031 | printk(KERN_WARNING "VFS: busy inodes on changed media or " |
| 1032 | "resized disk %s\n", name); |
| 1033 | } |
| 1034 | |
| 1035 | if (!bdev->bd_disk) |
| 1036 | return; |
| 1037 | if (disk_partitionable(bdev->bd_disk)) |
| 1038 | bdev->bd_invalidated = 1; |
| 1039 | } |
| 1040 | |
| 1041 | /** |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 1042 | * 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] | 1043 | * @disk: struct gendisk to check |
| 1044 | * @bdev: struct bdev to adjust. |
| 1045 | * |
| 1046 | * This routine checks to see if the bdev size does not match the disk size |
| 1047 | * and adjusts it if it differs. |
| 1048 | */ |
| 1049 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) |
| 1050 | { |
| 1051 | loff_t disk_size, bdev_size; |
| 1052 | |
| 1053 | disk_size = (loff_t)get_capacity(disk) << 9; |
| 1054 | bdev_size = i_size_read(bdev->bd_inode); |
| 1055 | if (disk_size != bdev_size) { |
| 1056 | char name[BDEVNAME_SIZE]; |
| 1057 | |
| 1058 | disk_name(disk, 0, name); |
| 1059 | printk(KERN_INFO |
| 1060 | "%s: detected capacity change from %lld to %lld\n", |
| 1061 | name, bdev_size, disk_size); |
| 1062 | i_size_write(bdev->bd_inode, disk_size); |
Andrew Patterson | 608aeef | 2008-09-04 14:27:45 -0600 | [diff] [blame] | 1063 | flush_disk(bdev); |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1064 | } |
| 1065 | } |
| 1066 | EXPORT_SYMBOL(check_disk_size_change); |
| 1067 | |
| 1068 | /** |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 1069 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1070 | * @disk: struct gendisk to be revalidated |
| 1071 | * |
| 1072 | * This routine is a wrapper for lower-level driver's revalidate_disk |
| 1073 | * call-backs. It is used to do common pre and post operations needed |
| 1074 | * for all revalidate_disk operations. |
| 1075 | */ |
| 1076 | int revalidate_disk(struct gendisk *disk) |
| 1077 | { |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1078 | struct block_device *bdev; |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1079 | int ret = 0; |
| 1080 | |
| 1081 | if (disk->fops->revalidate_disk) |
| 1082 | ret = disk->fops->revalidate_disk(disk); |
| 1083 | |
Andrew Patterson | c3279d1 | 2008-09-04 14:27:25 -0600 | [diff] [blame] | 1084 | bdev = bdget_disk(disk, 0); |
| 1085 | if (!bdev) |
| 1086 | return ret; |
| 1087 | |
| 1088 | mutex_lock(&bdev->bd_mutex); |
| 1089 | check_disk_size_change(disk, bdev); |
| 1090 | mutex_unlock(&bdev->bd_mutex); |
| 1091 | bdput(bdev); |
Andrew Patterson | 0c002c2 | 2008-09-04 14:27:20 -0600 | [diff] [blame] | 1092 | return ret; |
| 1093 | } |
| 1094 | EXPORT_SYMBOL(revalidate_disk); |
| 1095 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1096 | /* |
| 1097 | * This routine checks whether a removable media has been changed, |
| 1098 | * and invalidates all buffer-cache-entries in that case. This |
| 1099 | * is a relatively slow routine, so we have to try to minimize using |
| 1100 | * it. Thus it is called only upon a 'mount' or 'open'. This |
| 1101 | * is the best way of combining speed and utility, I think. |
| 1102 | * People changing diskettes in the middle of an operation deserve |
| 1103 | * to lose :-) |
| 1104 | */ |
| 1105 | int check_disk_change(struct block_device *bdev) |
| 1106 | { |
| 1107 | struct gendisk *disk = bdev->bd_disk; |
| 1108 | struct block_device_operations * bdops = disk->fops; |
| 1109 | |
| 1110 | if (!bdops->media_changed) |
| 1111 | return 0; |
| 1112 | if (!bdops->media_changed(bdev->bd_disk)) |
| 1113 | return 0; |
| 1114 | |
Andrew Patterson | 56ade44 | 2008-09-04 14:27:40 -0600 | [diff] [blame] | 1115 | flush_disk(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1116 | if (bdops->revalidate_disk) |
| 1117 | bdops->revalidate_disk(bdev->bd_disk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | return 1; |
| 1119 | } |
| 1120 | |
| 1121 | EXPORT_SYMBOL(check_disk_change); |
| 1122 | |
| 1123 | void bd_set_size(struct block_device *bdev, loff_t size) |
| 1124 | { |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 1125 | unsigned bsize = bdev_logical_block_size(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | |
| 1127 | bdev->bd_inode->i_size = size; |
| 1128 | while (bsize < PAGE_CACHE_SIZE) { |
| 1129 | if (size & bsize) |
| 1130 | break; |
| 1131 | bsize <<= 1; |
| 1132 | } |
| 1133 | bdev->bd_block_size = bsize; |
| 1134 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); |
| 1135 | } |
| 1136 | EXPORT_SYMBOL(bd_set_size); |
| 1137 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1138 | static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1139 | |
Peter Zijlstra | 6d740cd | 2007-02-20 13:58:18 -0800 | [diff] [blame] | 1140 | /* |
| 1141 | * bd_mutex locking: |
| 1142 | * |
| 1143 | * mutex_lock(part->bd_mutex) |
| 1144 | * mutex_lock_nested(whole->bd_mutex, 1) |
| 1145 | */ |
| 1146 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1147 | 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] | 1148 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1149 | struct gendisk *disk; |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1150 | int ret; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1151 | int partno; |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1152 | int perm = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1153 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1154 | if (mode & FMODE_READ) |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1155 | perm |= MAY_READ; |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1156 | if (mode & FMODE_WRITE) |
Al Viro | fe6e9c1 | 2008-06-23 08:30:55 -0400 | [diff] [blame] | 1157 | perm |= MAY_WRITE; |
| 1158 | /* |
| 1159 | * hooks: /n/, see "layering violations". |
| 1160 | */ |
| 1161 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); |
Al Viro | 8266602 | 2008-08-01 05:32:04 -0400 | [diff] [blame] | 1162 | if (ret != 0) { |
| 1163 | bdput(bdev); |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1164 | return ret; |
Al Viro | 8266602 | 2008-08-01 05:32:04 -0400 | [diff] [blame] | 1165 | } |
Pavel Emelyanov | 7db9cfd | 2008-06-05 22:46:27 -0700 | [diff] [blame] | 1166 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | lock_kernel(); |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1168 | restart: |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1169 | |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1170 | ret = -ENXIO; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1171 | disk = get_gendisk(bdev->bd_dev, &partno); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1172 | if (!disk) |
| 1173 | goto out_unlock_kernel; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | |
NeilBrown | 6796bf5 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1175 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | if (!bdev->bd_openers) { |
| 1177 | bdev->bd_disk = disk; |
| 1178 | bdev->bd_contains = bdev; |
Tejun Heo | cf771cb | 2008-09-03 09:01:09 +0200 | [diff] [blame] | 1179 | if (!partno) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | struct backing_dev_info *bdi; |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1181 | |
| 1182 | ret = -ENXIO; |
| 1183 | bdev->bd_part = disk_get_part(disk, partno); |
| 1184 | if (!bdev->bd_part) |
| 1185 | goto out_clear; |
| 1186 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1187 | if (disk->fops->open) { |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1188 | ret = disk->fops->open(bdev, mode); |
NeilBrown | d337482 | 2009-01-09 08:31:10 +1100 | [diff] [blame] | 1189 | if (ret == -ERESTARTSYS) { |
| 1190 | /* Lost a race with 'disk' being |
| 1191 | * deleted, try again. |
| 1192 | * See md.c |
| 1193 | */ |
| 1194 | disk_put_part(bdev->bd_part); |
| 1195 | bdev->bd_part = NULL; |
| 1196 | module_put(disk->fops->owner); |
| 1197 | put_disk(disk); |
| 1198 | bdev->bd_disk = NULL; |
| 1199 | mutex_unlock(&bdev->bd_mutex); |
| 1200 | goto restart; |
| 1201 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | if (ret) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1203 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1204 | } |
| 1205 | if (!bdev->bd_openers) { |
| 1206 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
| 1207 | bdi = blk_get_backing_dev_info(bdev); |
| 1208 | if (bdi == NULL) |
| 1209 | bdi = &default_backing_dev_info; |
| 1210 | bdev->bd_inode->i_data.backing_dev_info = bdi; |
| 1211 | } |
| 1212 | if (bdev->bd_invalidated) |
| 1213 | rescan_partitions(disk, bdev); |
| 1214 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | struct block_device *whole; |
| 1216 | whole = bdget_disk(disk, 0); |
| 1217 | ret = -ENOMEM; |
| 1218 | if (!whole) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1219 | goto out_clear; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1220 | BUG_ON(for_part); |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1221 | ret = __blkdev_get(whole, mode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1222 | if (ret) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1223 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | bdev->bd_contains = whole; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | bdev->bd_inode->i_data.backing_dev_info = |
| 1226 | whole->bd_inode->i_data.backing_dev_info; |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1227 | bdev->bd_part = disk_get_part(disk, partno); |
Tejun Heo | e71bf0d | 2008-09-03 09:03:02 +0200 | [diff] [blame] | 1228 | if (!(disk->flags & GENHD_FL_UP) || |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1229 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1230 | ret = -ENXIO; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1231 | goto out_clear; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | } |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1233 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | } |
| 1235 | } else { |
| 1236 | put_disk(disk); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1237 | module_put(disk->fops->owner); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1238 | disk = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1239 | if (bdev->bd_contains == bdev) { |
| 1240 | if (bdev->bd_disk->fops->open) { |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1241 | ret = bdev->bd_disk->fops->open(bdev, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | if (ret) |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1243 | goto out_unlock_bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | } |
| 1245 | if (bdev->bd_invalidated) |
| 1246 | rescan_partitions(bdev->bd_disk, bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | } |
| 1248 | } |
| 1249 | bdev->bd_openers++; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1250 | if (for_part) |
| 1251 | bdev->bd_part_count++; |
Arjan van de Ven | c039e31 | 2006-03-23 03:00:28 -0800 | [diff] [blame] | 1252 | mutex_unlock(&bdev->bd_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | unlock_kernel(); |
| 1254 | return 0; |
| 1255 | |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1256 | out_clear: |
Tejun Heo | 89f9749 | 2008-11-05 10:21:06 +0100 | [diff] [blame] | 1257 | disk_put_part(bdev->bd_part); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1258 | bdev->bd_disk = NULL; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1259 | bdev->bd_part = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1260 | bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info; |
| 1261 | if (bdev != bdev->bd_contains) |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1262 | __blkdev_put(bdev->bd_contains, mode, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1263 | bdev->bd_contains = NULL; |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1264 | out_unlock_bdev: |
Arjan van de Ven | c039e31 | 2006-03-23 03:00:28 -0800 | [diff] [blame] | 1265 | mutex_unlock(&bdev->bd_mutex); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1266 | out_unlock_kernel: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1267 | unlock_kernel(); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1268 | |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1269 | if (disk) |
| 1270 | module_put(disk->fops->owner); |
| 1271 | put_disk(disk); |
| 1272 | bdput(bdev); |
| 1273 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1274 | return ret; |
| 1275 | } |
| 1276 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1277 | int blkdev_get(struct block_device *bdev, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | { |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1279 | return __blkdev_get(bdev, mode, 0); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1281 | EXPORT_SYMBOL(blkdev_get); |
| 1282 | |
| 1283 | static int blkdev_open(struct inode * inode, struct file * filp) |
| 1284 | { |
| 1285 | struct block_device *bdev; |
| 1286 | int res; |
| 1287 | |
| 1288 | /* |
| 1289 | * Preserve backwards compatibility and allow large file access |
| 1290 | * even if userspace doesn't ask for it explicitly. Some mkfs |
| 1291 | * binary needs it. We might want to drop this workaround |
| 1292 | * during an unstable branch. |
| 1293 | */ |
| 1294 | filp->f_flags |= O_LARGEFILE; |
| 1295 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1296 | if (filp->f_flags & O_NDELAY) |
| 1297 | filp->f_mode |= FMODE_NDELAY; |
| 1298 | if (filp->f_flags & O_EXCL) |
| 1299 | filp->f_mode |= FMODE_EXCL; |
| 1300 | if ((filp->f_flags & O_ACCMODE) == 3) |
| 1301 | filp->f_mode |= FMODE_WRITE_IOCTL; |
| 1302 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | bdev = bd_acquire(inode); |
Pavel Emelianov | 6a2aae0 | 2006-10-28 10:38:33 -0700 | [diff] [blame] | 1304 | if (bdev == NULL) |
| 1305 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1307 | filp->f_mapping = bdev->bd_inode->i_mapping; |
| 1308 | |
| 1309 | res = blkdev_get(bdev, filp->f_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | if (res) |
| 1311 | return res; |
| 1312 | |
Christoph Hellwig | ebbefc0 | 2008-11-05 14:54:41 +0100 | [diff] [blame] | 1313 | if (filp->f_mode & FMODE_EXCL) { |
| 1314 | res = bd_claim(bdev, filp); |
| 1315 | if (res) |
| 1316 | goto out_blkdev_put; |
| 1317 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | |
Christoph Hellwig | ebbefc0 | 2008-11-05 14:54:41 +0100 | [diff] [blame] | 1319 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | |
Christoph Hellwig | ebbefc0 | 2008-11-05 14:54:41 +0100 | [diff] [blame] | 1321 | out_blkdev_put: |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1322 | blkdev_put(bdev, filp->f_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | return res; |
| 1324 | } |
| 1325 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1326 | static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1327 | { |
| 1328 | int ret = 0; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1329 | struct gendisk *disk = bdev->bd_disk; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1330 | struct block_device *victim = NULL; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1331 | |
NeilBrown | 6796bf5 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1332 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1333 | lock_kernel(); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1334 | if (for_part) |
| 1335 | bdev->bd_part_count--; |
| 1336 | |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1337 | if (!--bdev->bd_openers) { |
| 1338 | sync_blockdev(bdev); |
| 1339 | kill_bdev(bdev); |
| 1340 | } |
| 1341 | if (bdev->bd_contains == bdev) { |
| 1342 | if (disk->fops->release) |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1343 | ret = disk->fops->release(disk, mode); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1344 | } |
| 1345 | if (!bdev->bd_openers) { |
| 1346 | struct module *owner = disk->fops->owner; |
| 1347 | |
| 1348 | put_disk(disk); |
| 1349 | module_put(owner); |
Tejun Heo | 0762b8b | 2008-08-25 19:56:12 +0900 | [diff] [blame] | 1350 | disk_put_part(bdev->bd_part); |
| 1351 | bdev->bd_part = NULL; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1352 | bdev->bd_disk = NULL; |
| 1353 | bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info; |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1354 | if (bdev != bdev->bd_contains) |
| 1355 | victim = bdev->bd_contains; |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1356 | bdev->bd_contains = NULL; |
| 1357 | } |
| 1358 | unlock_kernel(); |
| 1359 | mutex_unlock(&bdev->bd_mutex); |
| 1360 | bdput(bdev); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1361 | if (victim) |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1362 | __blkdev_put(victim, mode, 1); |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1363 | return ret; |
| 1364 | } |
| 1365 | |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1366 | int blkdev_put(struct block_device *bdev, fmode_t mode) |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1367 | { |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1368 | return __blkdev_put(bdev, mode, 0); |
NeilBrown | 37be412 | 2006-12-08 02:36:16 -0800 | [diff] [blame] | 1369 | } |
Peter Zijlstra | 2e7b651 | 2006-12-08 02:36:13 -0800 | [diff] [blame] | 1370 | EXPORT_SYMBOL(blkdev_put); |
| 1371 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | static int blkdev_close(struct inode * inode, struct file * filp) |
| 1373 | { |
| 1374 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
| 1375 | if (bdev->bd_holder == filp) |
| 1376 | bd_release(bdev); |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1377 | return blkdev_put(bdev, filp->f_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | } |
| 1379 | |
Arnd Bergmann | bb93e3a | 2005-06-23 00:10:15 -0700 | [diff] [blame] | 1380 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | { |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1382 | struct block_device *bdev = I_BDEV(file->f_mapping->host); |
| 1383 | fmode_t mode = file->f_mode; |
Christoph Hellwig | fd4ce1a | 2008-11-05 14:58:42 +0100 | [diff] [blame] | 1384 | |
| 1385 | /* |
| 1386 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have |
| 1387 | * to updated it before every ioctl. |
| 1388 | */ |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1389 | if (file->f_flags & O_NDELAY) |
Christoph Hellwig | fd4ce1a | 2008-11-05 14:58:42 +0100 | [diff] [blame] | 1390 | mode |= FMODE_NDELAY; |
| 1391 | else |
| 1392 | mode &= ~FMODE_NDELAY; |
| 1393 | |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1394 | return blkdev_ioctl(bdev, mode, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | } |
| 1396 | |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1397 | /* |
| 1398 | * Try to release a page associated with block device when the system |
| 1399 | * is under memory pressure. |
| 1400 | */ |
| 1401 | static int blkdev_releasepage(struct page *page, gfp_t wait) |
| 1402 | { |
| 1403 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; |
| 1404 | |
| 1405 | if (super && super->s_op->bdev_try_to_free_page) |
| 1406 | return super->s_op->bdev_try_to_free_page(super, page, wait); |
| 1407 | |
| 1408 | return try_to_free_buffers(page); |
| 1409 | } |
| 1410 | |
Adrian Bunk | 4c54ac62 | 2008-02-18 13:48:31 +0100 | [diff] [blame] | 1411 | static const struct address_space_operations def_blk_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1412 | .readpage = blkdev_readpage, |
| 1413 | .writepage = blkdev_writepage, |
| 1414 | .sync_page = block_sync_page, |
Nick Piggin | 6272b5a | 2007-10-16 01:25:04 -0700 | [diff] [blame] | 1415 | .write_begin = blkdev_write_begin, |
| 1416 | .write_end = blkdev_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | .writepages = generic_writepages, |
Theodore Ts'o | 87d8fe1 | 2009-01-03 09:47:09 -0500 | [diff] [blame] | 1418 | .releasepage = blkdev_releasepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | .direct_IO = blkdev_direct_IO, |
| 1420 | }; |
| 1421 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 1422 | const struct file_operations def_blk_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | .open = blkdev_open, |
| 1424 | .release = blkdev_close, |
| 1425 | .llseek = block_llseek, |
Badari Pulavarty | 543ade1 | 2006-09-30 23:28:48 -0700 | [diff] [blame] | 1426 | .read = do_sync_read, |
| 1427 | .write = do_sync_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | .aio_read = generic_file_aio_read, |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 1429 | .aio_write = generic_file_aio_write_nolock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | .mmap = generic_file_mmap, |
| 1431 | .fsync = block_fsync, |
Arnd Bergmann | bb93e3a | 2005-06-23 00:10:15 -0700 | [diff] [blame] | 1432 | .unlocked_ioctl = block_ioctl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | #ifdef CONFIG_COMPAT |
| 1434 | .compat_ioctl = compat_blkdev_ioctl, |
| 1435 | #endif |
Jens Axboe | 7f9c51f | 2006-05-01 19:59:32 +0200 | [diff] [blame] | 1436 | .splice_read = generic_file_splice_read, |
| 1437 | .splice_write = generic_file_splice_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | }; |
| 1439 | |
| 1440 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) |
| 1441 | { |
| 1442 | int res; |
| 1443 | mm_segment_t old_fs = get_fs(); |
| 1444 | set_fs(KERNEL_DS); |
Al Viro | 56b26ad | 2008-09-19 03:17:36 -0400 | [diff] [blame] | 1445 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | set_fs(old_fs); |
| 1447 | return res; |
| 1448 | } |
| 1449 | |
| 1450 | EXPORT_SYMBOL(ioctl_by_bdev); |
| 1451 | |
| 1452 | /** |
| 1453 | * lookup_bdev - lookup a struct block_device by name |
Randy Dunlap | 94e2959 | 2009-01-06 14:41:15 -0800 | [diff] [blame] | 1454 | * @pathname: special file representing the block device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1455 | * |
Randy Dunlap | 57d1b53 | 2008-10-09 10:42:38 +0200 | [diff] [blame] | 1456 | * Get a reference to the blockdevice at @pathname in the current |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1457 | * namespace if possible and return it. Return ERR_PTR(error) |
| 1458 | * otherwise. |
| 1459 | */ |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1460 | struct block_device *lookup_bdev(const char *pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | { |
| 1462 | struct block_device *bdev; |
| 1463 | struct inode *inode; |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1464 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | int error; |
| 1466 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1467 | if (!pathname || !*pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1468 | return ERR_PTR(-EINVAL); |
| 1469 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1470 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1471 | if (error) |
| 1472 | return ERR_PTR(error); |
| 1473 | |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1474 | inode = path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | error = -ENOTBLK; |
| 1476 | if (!S_ISBLK(inode->i_mode)) |
| 1477 | goto fail; |
| 1478 | error = -EACCES; |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1479 | if (path.mnt->mnt_flags & MNT_NODEV) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | goto fail; |
| 1481 | error = -ENOMEM; |
| 1482 | bdev = bd_acquire(inode); |
| 1483 | if (!bdev) |
| 1484 | goto fail; |
| 1485 | out: |
Al Viro | 421748e | 2008-08-02 01:04:36 -0400 | [diff] [blame] | 1486 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1487 | return bdev; |
| 1488 | fail: |
| 1489 | bdev = ERR_PTR(error); |
| 1490 | goto out; |
| 1491 | } |
Al Viro | d5686b4 | 2008-08-01 05:00:11 -0400 | [diff] [blame] | 1492 | EXPORT_SYMBOL(lookup_bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | |
| 1494 | /** |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1495 | * open_bdev_exclusive - open a block device by name and set it up for use |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1496 | * |
| 1497 | * @path: special file representing the block device |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1498 | * @mode: FMODE_... combination to pass be used |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | * @holder: owner for exclusion |
| 1500 | * |
| 1501 | * Open the blockdevice described by the special file at @path, claim it |
| 1502 | * for the @holder. |
| 1503 | */ |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1504 | struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1505 | { |
| 1506 | struct block_device *bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | int error = 0; |
| 1508 | |
| 1509 | bdev = lookup_bdev(path); |
| 1510 | if (IS_ERR(bdev)) |
| 1511 | return bdev; |
| 1512 | |
Al Viro | 572c489 | 2007-10-08 13:24:05 -0400 | [diff] [blame] | 1513 | error = blkdev_get(bdev, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1514 | if (error) |
| 1515 | return ERR_PTR(error); |
| 1516 | error = -EACCES; |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1517 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1518 | goto blkdev_put; |
| 1519 | error = bd_claim(bdev, holder); |
| 1520 | if (error) |
| 1521 | goto blkdev_put; |
| 1522 | |
| 1523 | return bdev; |
| 1524 | |
| 1525 | blkdev_put: |
Al Viro | 9a1c354 | 2008-02-22 20:40:24 -0500 | [diff] [blame] | 1526 | blkdev_put(bdev, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1527 | return ERR_PTR(error); |
| 1528 | } |
| 1529 | |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1530 | EXPORT_SYMBOL(open_bdev_exclusive); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1531 | |
| 1532 | /** |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1533 | * close_bdev_exclusive - close a blockdevice opened by open_bdev_exclusive() |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1534 | * |
| 1535 | * @bdev: blockdevice to close |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1536 | * @mode: mode, must match that used to open. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1537 | * |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1538 | * This is the counterpart to open_bdev_exclusive(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | */ |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1540 | void close_bdev_exclusive(struct block_device *bdev, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | { |
| 1542 | bd_release(bdev); |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1543 | blkdev_put(bdev, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1544 | } |
| 1545 | |
Al Viro | 30c40d2 | 2008-02-22 19:50:45 -0500 | [diff] [blame] | 1546 | EXPORT_SYMBOL(close_bdev_exclusive); |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1547 | |
| 1548 | int __invalidate_device(struct block_device *bdev) |
| 1549 | { |
| 1550 | struct super_block *sb = get_super(bdev); |
| 1551 | int res = 0; |
| 1552 | |
| 1553 | if (sb) { |
| 1554 | /* |
| 1555 | * no need to lock the super, get_super holds the |
| 1556 | * read mutex so the filesystem cannot go away |
| 1557 | * under us (->put_super runs with the write lock |
| 1558 | * hold). |
| 1559 | */ |
| 1560 | shrink_dcache_sb(sb); |
| 1561 | res = invalidate_inodes(sb); |
| 1562 | drop_super(sb); |
| 1563 | } |
Peter Zijlstra | f98393a | 2007-05-06 14:49:54 -0700 | [diff] [blame] | 1564 | invalidate_bdev(bdev); |
David Howells | b71e8a4 | 2006-08-29 19:06:11 +0100 | [diff] [blame] | 1565 | return res; |
| 1566 | } |
| 1567 | EXPORT_SYMBOL(__invalidate_device); |