Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * fs/fs-writeback.c |
| 3 | * |
| 4 | * Copyright (C) 2002, Linus Torvalds. |
| 5 | * |
| 6 | * Contains all the functions related to writing back and waiting |
| 7 | * upon dirty inodes against superblocks, and writing back dirty |
| 8 | * pages against inodes. ie: data writeback. Writeout of the |
| 9 | * inode itself is not handled here. |
| 10 | * |
Francois Cami | e1f8e87 | 2008-10-15 22:01:59 -0700 | [diff] [blame] | 11 | * 10Apr2002 Andrew Morton |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Split out of fs/inode.c |
| 13 | * Additions for address_space-based writeback |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
Jens Axboe | f5ff842 | 2007-09-21 09:19:54 +0200 | [diff] [blame] | 17 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/spinlock.h> |
| 19 | #include <linux/sched.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/mm.h> |
| 22 | #include <linux/writeback.h> |
| 23 | #include <linux/blkdev.h> |
| 24 | #include <linux/backing-dev.h> |
| 25 | #include <linux/buffer_head.h> |
David Howells | 07f3f05c | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 26 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 28 | |
| 29 | /** |
| 30 | * writeback_acquire - attempt to get exclusive writeback access to a device |
| 31 | * @bdi: the device's backing_dev_info structure |
| 32 | * |
| 33 | * It is a waste of resources to have more than one pdflush thread blocked on |
| 34 | * a single request queue. Exclusion at the request_queue level is obtained |
| 35 | * via a flag in the request_queue's backing_dev_info.state. |
| 36 | * |
| 37 | * Non-request_queue-backed address_spaces will share default_backing_dev_info, |
| 38 | * unless they implement their own. Which is somewhat inefficient, as this |
| 39 | * may prevent concurrent writeback against multiple devices. |
| 40 | */ |
| 41 | static int writeback_acquire(struct backing_dev_info *bdi) |
| 42 | { |
| 43 | return !test_and_set_bit(BDI_pdflush, &bdi->state); |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * writeback_in_progress - determine whether there is writeback in progress |
| 48 | * @bdi: the device's backing_dev_info structure. |
| 49 | * |
| 50 | * Determine whether there is writeback in progress against a backing device. |
| 51 | */ |
| 52 | int writeback_in_progress(struct backing_dev_info *bdi) |
| 53 | { |
| 54 | return test_bit(BDI_pdflush, &bdi->state); |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * writeback_release - relinquish exclusive writeback access against a device. |
| 59 | * @bdi: the device's backing_dev_info structure |
| 60 | */ |
| 61 | static void writeback_release(struct backing_dev_info *bdi) |
| 62 | { |
| 63 | BUG_ON(!writeback_in_progress(bdi)); |
| 64 | clear_bit(BDI_pdflush, &bdi->state); |
| 65 | } |
| 66 | |
Nick Piggin | 4195f73 | 2009-05-28 09:01:15 +0200 | [diff] [blame] | 67 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) |
| 68 | { |
| 69 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { |
| 70 | struct dentry *dentry; |
| 71 | const char *name = "?"; |
| 72 | |
| 73 | dentry = d_find_alias(inode); |
| 74 | if (dentry) { |
| 75 | spin_lock(&dentry->d_lock); |
| 76 | name = (const char *) dentry->d_name.name; |
| 77 | } |
| 78 | printk(KERN_DEBUG |
| 79 | "%s(%d): dirtied inode %lu (%s) on %s\n", |
| 80 | current->comm, task_pid_nr(current), inode->i_ino, |
| 81 | name, inode->i_sb->s_id); |
| 82 | if (dentry) { |
| 83 | spin_unlock(&dentry->d_lock); |
| 84 | dput(dentry); |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | /** |
| 90 | * __mark_inode_dirty - internal function |
| 91 | * @inode: inode to mark |
| 92 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) |
| 93 | * Mark an inode as dirty. Callers should use mark_inode_dirty or |
| 94 | * mark_inode_dirty_sync. |
| 95 | * |
| 96 | * Put the inode on the super block's dirty list. |
| 97 | * |
| 98 | * CAREFUL! We mark it dirty unconditionally, but move it onto the |
| 99 | * dirty list only if it is hashed or if it refers to a blockdev. |
| 100 | * If it was not hashed, it will never be added to the dirty list |
| 101 | * even if it is later hashed, as it will have been marked dirty already. |
| 102 | * |
| 103 | * In short, make sure you hash any inodes _before_ you start marking |
| 104 | * them dirty. |
| 105 | * |
| 106 | * This function *must* be atomic for the I_DIRTY_PAGES case - |
| 107 | * set_page_dirty() is called under spinlock in several places. |
| 108 | * |
| 109 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
| 110 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of |
| 111 | * the kernel-internal blockdev inode represents the dirtying time of the |
| 112 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use |
| 113 | * page->mapping->host, so the page-dirtying time is recorded in the internal |
| 114 | * blockdev inode. |
| 115 | */ |
| 116 | void __mark_inode_dirty(struct inode *inode, int flags) |
| 117 | { |
| 118 | struct super_block *sb = inode->i_sb; |
| 119 | |
| 120 | /* |
| 121 | * Don't do this for I_DIRTY_PAGES - that doesn't actually |
| 122 | * dirty the inode itself |
| 123 | */ |
| 124 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
| 125 | if (sb->s_op->dirty_inode) |
| 126 | sb->s_op->dirty_inode(inode); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * make sure that changes are seen by all cpus before we test i_state |
| 131 | * -- mikulas |
| 132 | */ |
| 133 | smp_mb(); |
| 134 | |
| 135 | /* avoid the locking if we can */ |
| 136 | if ((inode->i_state & flags) == flags) |
| 137 | return; |
| 138 | |
Nick Piggin | 4195f73 | 2009-05-28 09:01:15 +0200 | [diff] [blame] | 139 | if (unlikely(block_dump)) |
| 140 | block_dump___mark_inode_dirty(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
| 142 | spin_lock(&inode_lock); |
| 143 | if ((inode->i_state & flags) != flags) { |
| 144 | const int was_dirty = inode->i_state & I_DIRTY; |
| 145 | |
| 146 | inode->i_state |= flags; |
| 147 | |
| 148 | /* |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 149 | * If the inode is being synced, just update its dirty state. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | * The unlocker will place the inode on the appropriate |
| 151 | * superblock list, based upon its state. |
| 152 | */ |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 153 | if (inode->i_state & I_SYNC) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | goto out; |
| 155 | |
| 156 | /* |
| 157 | * Only add valid (hashed) inodes to the superblock's |
| 158 | * dirty list. Add blockdev inodes as well. |
| 159 | */ |
| 160 | if (!S_ISBLK(inode->i_mode)) { |
| 161 | if (hlist_unhashed(&inode->i_hash)) |
| 162 | goto out; |
| 163 | } |
| 164 | if (inode->i_state & (I_FREEING|I_CLEAR)) |
| 165 | goto out; |
| 166 | |
| 167 | /* |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 168 | * If the inode was already on s_dirty/s_io/s_more_io, don't |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | * reposition it (that would break s_dirty time-ordering). |
| 170 | */ |
| 171 | if (!was_dirty) { |
| 172 | inode->dirtied_when = jiffies; |
| 173 | list_move(&inode->i_list, &sb->s_dirty); |
| 174 | } |
| 175 | } |
| 176 | out: |
| 177 | spin_unlock(&inode_lock); |
| 178 | } |
| 179 | |
| 180 | EXPORT_SYMBOL(__mark_inode_dirty); |
| 181 | |
| 182 | static int write_inode(struct inode *inode, int sync) |
| 183 | { |
| 184 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) |
| 185 | return inode->i_sb->s_op->write_inode(inode, sync); |
| 186 | return 0; |
| 187 | } |
| 188 | |
| 189 | /* |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 190 | * Redirty an inode: set its when-it-was dirtied timestamp and move it to the |
| 191 | * furthest end of its superblock's dirty-inode list. |
| 192 | * |
| 193 | * Before stamping the inode's ->dirtied_when, we check to see whether it is |
| 194 | * already the most-recently-dirtied inode on the s_dirty list. If that is |
| 195 | * the case then the inode must have been redirtied while it was being written |
| 196 | * out and we don't reset its dirtied_when. |
| 197 | */ |
| 198 | static void redirty_tail(struct inode *inode) |
| 199 | { |
| 200 | struct super_block *sb = inode->i_sb; |
| 201 | |
| 202 | if (!list_empty(&sb->s_dirty)) { |
| 203 | struct inode *tail_inode; |
| 204 | |
| 205 | tail_inode = list_entry(sb->s_dirty.next, struct inode, i_list); |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 206 | if (time_before(inode->dirtied_when, |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 207 | tail_inode->dirtied_when)) |
| 208 | inode->dirtied_when = jiffies; |
| 209 | } |
| 210 | list_move(&inode->i_list, &sb->s_dirty); |
| 211 | } |
| 212 | |
| 213 | /* |
Ken Chen | 0e0f4fc | 2007-10-16 23:30:38 -0700 | [diff] [blame] | 214 | * requeue inode for re-scanning after sb->s_io list is exhausted. |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 215 | */ |
Ken Chen | 0e0f4fc | 2007-10-16 23:30:38 -0700 | [diff] [blame] | 216 | static void requeue_io(struct inode *inode) |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 217 | { |
Ken Chen | 0e0f4fc | 2007-10-16 23:30:38 -0700 | [diff] [blame] | 218 | list_move(&inode->i_list, &inode->i_sb->s_more_io); |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 219 | } |
| 220 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 221 | static void inode_sync_complete(struct inode *inode) |
| 222 | { |
| 223 | /* |
| 224 | * Prevent speculative execution through spin_unlock(&inode_lock); |
| 225 | */ |
| 226 | smp_mb(); |
| 227 | wake_up_bit(&inode->i_state, __I_SYNC); |
| 228 | } |
| 229 | |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 230 | static bool inode_dirtied_after(struct inode *inode, unsigned long t) |
| 231 | { |
| 232 | bool ret = time_after(inode->dirtied_when, t); |
| 233 | #ifndef CONFIG_64BIT |
| 234 | /* |
| 235 | * For inodes being constantly redirtied, dirtied_when can get stuck. |
| 236 | * It _appears_ to be in the future, but is actually in distant past. |
| 237 | * This test is necessary to prevent such wrapped-around relative times |
| 238 | * from permanently stopping the whole pdflush writeback. |
| 239 | */ |
| 240 | ret = ret && time_before_eq(inode->dirtied_when, jiffies); |
| 241 | #endif |
| 242 | return ret; |
| 243 | } |
| 244 | |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 245 | /* |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 246 | * Move expired dirty inodes from @delaying_queue to @dispatch_queue. |
| 247 | */ |
| 248 | static void move_expired_inodes(struct list_head *delaying_queue, |
| 249 | struct list_head *dispatch_queue, |
| 250 | unsigned long *older_than_this) |
| 251 | { |
| 252 | while (!list_empty(delaying_queue)) { |
| 253 | struct inode *inode = list_entry(delaying_queue->prev, |
| 254 | struct inode, i_list); |
| 255 | if (older_than_this && |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 256 | inode_dirtied_after(inode, *older_than_this)) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 257 | break; |
| 258 | list_move(&inode->i_list, dispatch_queue); |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | /* |
| 263 | * Queue all expired dirty inodes for io, eldest first. |
| 264 | */ |
| 265 | static void queue_io(struct super_block *sb, |
| 266 | unsigned long *older_than_this) |
| 267 | { |
| 268 | list_splice_init(&sb->s_more_io, sb->s_io.prev); |
| 269 | move_expired_inodes(&sb->s_dirty, &sb->s_io, older_than_this); |
| 270 | } |
| 271 | |
Fengguang Wu | 08d8e97 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 272 | int sb_has_dirty_inodes(struct super_block *sb) |
| 273 | { |
| 274 | return !list_empty(&sb->s_dirty) || |
| 275 | !list_empty(&sb->s_io) || |
| 276 | !list_empty(&sb->s_more_io); |
| 277 | } |
| 278 | EXPORT_SYMBOL(sb_has_dirty_inodes); |
| 279 | |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 280 | /* |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 281 | * Wait for writeback on an inode to complete. |
| 282 | */ |
| 283 | static void inode_wait_for_writeback(struct inode *inode) |
| 284 | { |
| 285 | DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); |
| 286 | wait_queue_head_t *wqh; |
| 287 | |
| 288 | wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
| 289 | do { |
| 290 | spin_unlock(&inode_lock); |
| 291 | __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); |
| 292 | spin_lock(&inode_lock); |
| 293 | } while (inode->i_state & I_SYNC); |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * Write out an inode's dirty pages. Called under inode_lock. Either the |
| 298 | * caller has ref on the inode (either via __iget or via syscall against an fd) |
| 299 | * or the inode has I_WILL_FREE set (via generic_forget_inode) |
| 300 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | * If `wait' is set, wait on the writeout. |
| 302 | * |
| 303 | * The whole writeout design is quite complex and fragile. We want to avoid |
| 304 | * starvation of particular inodes when others are being redirtied, prevent |
| 305 | * livelocks, etc. |
| 306 | * |
| 307 | * Called under inode_lock. |
| 308 | */ |
| 309 | static int |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 310 | writeback_single_inode(struct inode *inode, struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | struct address_space *mapping = inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | int wait = wbc->sync_mode == WB_SYNC_ALL; |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 314 | unsigned dirty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | int ret; |
| 316 | |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 317 | if (!atomic_read(&inode->i_count)) |
| 318 | WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); |
| 319 | else |
| 320 | WARN_ON(inode->i_state & I_WILL_FREE); |
| 321 | |
| 322 | if (inode->i_state & I_SYNC) { |
| 323 | /* |
| 324 | * If this inode is locked for writeback and we are not doing |
| 325 | * writeback-for-data-integrity, move it to s_more_io so that |
| 326 | * writeback can proceed with the other inodes on s_io. |
| 327 | * |
| 328 | * We'll have another go at writing back this inode when we |
| 329 | * completed a full scan of s_io. |
| 330 | */ |
| 331 | if (!wait) { |
| 332 | requeue_io(inode); |
| 333 | return 0; |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * It's a data-integrity sync. We must wait. |
| 338 | */ |
| 339 | inode_wait_for_writeback(inode); |
| 340 | } |
| 341 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 342 | BUG_ON(inode->i_state & I_SYNC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 344 | /* Set I_SYNC, reset I_DIRTY */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | dirty = inode->i_state & I_DIRTY; |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 346 | inode->i_state |= I_SYNC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | inode->i_state &= ~I_DIRTY; |
| 348 | |
| 349 | spin_unlock(&inode_lock); |
| 350 | |
| 351 | ret = do_writepages(mapping, wbc); |
| 352 | |
| 353 | /* Don't write the inode if only I_DIRTY_PAGES was set */ |
| 354 | if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
| 355 | int err = write_inode(inode, wait); |
| 356 | if (ret == 0) |
| 357 | ret = err; |
| 358 | } |
| 359 | |
| 360 | if (wait) { |
| 361 | int err = filemap_fdatawait(mapping); |
| 362 | if (ret == 0) |
| 363 | ret = err; |
| 364 | } |
| 365 | |
| 366 | spin_lock(&inode_lock); |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 367 | inode->i_state &= ~I_SYNC; |
Wu Fengguang | 84a8924 | 2009-06-16 15:33:17 -0700 | [diff] [blame] | 368 | if (!(inode->i_state & (I_FREEING | I_CLEAR))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | if (!(inode->i_state & I_DIRTY) && |
| 370 | mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { |
| 371 | /* |
| 372 | * We didn't write back all the pages. nfs_writepages() |
| 373 | * sometimes bales out without doing anything. Redirty |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 374 | * the inode; Move it from s_io onto s_more_io/s_dirty. |
Andrew Morton | 1b43ef9 | 2007-10-16 23:30:35 -0700 | [diff] [blame] | 375 | */ |
| 376 | /* |
| 377 | * akpm: if the caller was the kupdate function we put |
| 378 | * this inode at the head of s_dirty so it gets first |
| 379 | * consideration. Otherwise, move it to the tail, for |
| 380 | * the reasons described there. I'm not really sure |
| 381 | * how much sense this makes. Presumably I had a good |
| 382 | * reasons for doing it this way, and I'd rather not |
| 383 | * muck with it at present. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | */ |
| 385 | if (wbc->for_kupdate) { |
| 386 | /* |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 387 | * For the kupdate function we move the inode |
| 388 | * to s_more_io so it will get more writeout as |
| 389 | * soon as the queue becomes uncongested. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | */ |
| 391 | inode->i_state |= I_DIRTY_PAGES; |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 392 | if (wbc->nr_to_write <= 0) { |
| 393 | /* |
| 394 | * slice used up: queue for next turn |
| 395 | */ |
| 396 | requeue_io(inode); |
| 397 | } else { |
| 398 | /* |
| 399 | * somehow blocked: retry later |
| 400 | */ |
| 401 | redirty_tail(inode); |
| 402 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | } else { |
| 404 | /* |
| 405 | * Otherwise fully redirty the inode so that |
| 406 | * other inodes on this superblock will get some |
| 407 | * writeout. Otherwise heavy writing to one |
| 408 | * file would indefinitely suspend writeout of |
| 409 | * all the other files. |
| 410 | */ |
| 411 | inode->i_state |= I_DIRTY_PAGES; |
Andrew Morton | 1b43ef9 | 2007-10-16 23:30:35 -0700 | [diff] [blame] | 412 | redirty_tail(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | } |
| 414 | } else if (inode->i_state & I_DIRTY) { |
| 415 | /* |
| 416 | * Someone redirtied the inode while were writing back |
| 417 | * the pages. |
| 418 | */ |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 419 | redirty_tail(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | } else if (atomic_read(&inode->i_count)) { |
| 421 | /* |
| 422 | * The inode is clean, inuse |
| 423 | */ |
| 424 | list_move(&inode->i_list, &inode_in_use); |
| 425 | } else { |
| 426 | /* |
| 427 | * The inode is clean, unused |
| 428 | */ |
| 429 | list_move(&inode->i_list, &inode_unused); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | } |
| 431 | } |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 432 | inode_sync_complete(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | return ret; |
| 434 | } |
| 435 | |
| 436 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | * Write out a superblock's list of dirty inodes. A wait will be performed |
| 438 | * upon no inodes, all inodes or the final one, depending upon sync_mode. |
| 439 | * |
| 440 | * If older_than_this is non-NULL, then only write out inodes which |
| 441 | * had their first dirtying at a time earlier than *older_than_this. |
| 442 | * |
Masatake YAMATO | 3e3cb64 | 2009-02-25 22:51:57 +0900 | [diff] [blame] | 443 | * If we're a pdflush thread, then implement pdflush collision avoidance |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | * against the entire list. |
| 445 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | * If `bdi' is non-zero then we're being asked to writeback a specific queue. |
| 447 | * This function assumes that the blockdev superblock's inodes are backed by |
| 448 | * a variety of queues, so all inodes are searched. For other superblocks, |
| 449 | * assume that all inodes are backed by the same queue. |
| 450 | * |
| 451 | * FIXME: this linear search could get expensive with many fileystems. But |
| 452 | * how to fix? We need to go from an address_space to all inodes which share |
| 453 | * a queue with that address_space. (Easy: have a global "dirty superblocks" |
| 454 | * list). |
| 455 | * |
| 456 | * The inodes to be written are parked on sb->s_io. They are moved back onto |
| 457 | * sb->s_dirty as they are selected for writing. This way, none can be missed |
| 458 | * on the writer throttling path, and we get decent balancing between many |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 459 | * throttled threads: we don't want them all piling up on inode_sync_wait. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | */ |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 461 | static void generic_sync_sb_inodes(struct super_block *sb, |
| 462 | struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | { |
| 464 | const unsigned long start = jiffies; /* livelock avoidance */ |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 465 | int sync = wbc->sync_mode == WB_SYNC_ALL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | |
Hans Reiser | ae8547b | 2008-05-07 15:48:57 +0300 | [diff] [blame] | 467 | spin_lock(&inode_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | if (!wbc->for_kupdate || list_empty(&sb->s_io)) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 469 | queue_io(sb, wbc->older_than_this); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | |
| 471 | while (!list_empty(&sb->s_io)) { |
| 472 | struct inode *inode = list_entry(sb->s_io.prev, |
| 473 | struct inode, i_list); |
| 474 | struct address_space *mapping = inode->i_mapping; |
| 475 | struct backing_dev_info *bdi = mapping->backing_dev_info; |
| 476 | long pages_skipped; |
| 477 | |
| 478 | if (!bdi_cap_writeback_dirty(bdi)) { |
Andrew Morton | 9852a0e7 | 2007-10-16 23:30:33 -0700 | [diff] [blame] | 479 | redirty_tail(inode); |
David Howells | 7b0de42 | 2006-08-29 19:06:07 +0100 | [diff] [blame] | 480 | if (sb_is_blkdev_sb(sb)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | /* |
| 482 | * Dirty memory-backed blockdev: the ramdisk |
| 483 | * driver does this. Skip just this inode |
| 484 | */ |
| 485 | continue; |
| 486 | } |
| 487 | /* |
| 488 | * Dirty memory-backed inode against a filesystem other |
| 489 | * than the kernel-internal bdev filesystem. Skip the |
| 490 | * entire superblock. |
| 491 | */ |
| 492 | break; |
| 493 | } |
| 494 | |
Wu Fengguang | 84a8924 | 2009-06-16 15:33:17 -0700 | [diff] [blame] | 495 | if (inode->i_state & (I_NEW | I_WILL_FREE)) { |
Nick Piggin | 7ef0d73 | 2009-03-12 14:31:38 -0700 | [diff] [blame] | 496 | requeue_io(inode); |
| 497 | continue; |
| 498 | } |
| 499 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | if (wbc->nonblocking && bdi_write_congested(bdi)) { |
| 501 | wbc->encountered_congestion = 1; |
David Howells | 7b0de42 | 2006-08-29 19:06:07 +0100 | [diff] [blame] | 502 | if (!sb_is_blkdev_sb(sb)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | break; /* Skip a congested fs */ |
Ken Chen | 0e0f4fc | 2007-10-16 23:30:38 -0700 | [diff] [blame] | 504 | requeue_io(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | continue; /* Skip a congested blockdev */ |
| 506 | } |
| 507 | |
| 508 | if (wbc->bdi && bdi != wbc->bdi) { |
David Howells | 7b0de42 | 2006-08-29 19:06:07 +0100 | [diff] [blame] | 509 | if (!sb_is_blkdev_sb(sb)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | break; /* fs has the wrong queue */ |
Ken Chen | 0e0f4fc | 2007-10-16 23:30:38 -0700 | [diff] [blame] | 511 | requeue_io(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | continue; /* blockdev has wrong queue */ |
| 513 | } |
| 514 | |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 515 | /* |
| 516 | * Was this inode dirtied after sync_sb_inodes was called? |
| 517 | * This keeps sync from extra jobs and livelock. |
| 518 | */ |
| 519 | if (inode_dirtied_after(inode, start)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | break; |
| 521 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | /* Is another pdflush already flushing this queue? */ |
| 523 | if (current_is_pdflush() && !writeback_acquire(bdi)) |
| 524 | break; |
| 525 | |
Wu Fengguang | 84a8924 | 2009-06-16 15:33:17 -0700 | [diff] [blame] | 526 | BUG_ON(inode->i_state & (I_FREEING | I_CLEAR)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | __iget(inode); |
| 528 | pages_skipped = wbc->pages_skipped; |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 529 | writeback_single_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | if (current_is_pdflush()) |
| 531 | writeback_release(bdi); |
| 532 | if (wbc->pages_skipped != pages_skipped) { |
| 533 | /* |
| 534 | * writeback is not making progress due to locked |
| 535 | * buffers. Skip this inode for now. |
| 536 | */ |
Andrew Morton | f57b9b7 | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 537 | redirty_tail(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | } |
| 539 | spin_unlock(&inode_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | iput(inode); |
OGAWA Hirofumi | 4ffc844 | 2006-03-25 03:07:44 -0800 | [diff] [blame] | 541 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | spin_lock(&inode_lock); |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 543 | if (wbc->nr_to_write <= 0) { |
| 544 | wbc->more_io = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | break; |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 546 | } |
| 547 | if (!list_empty(&sb->s_more_io)) |
| 548 | wbc->more_io = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | } |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 550 | |
| 551 | if (sync) { |
| 552 | struct inode *inode, *old_inode = NULL; |
| 553 | |
| 554 | /* |
| 555 | * Data integrity sync. Must wait for all pages under writeback, |
| 556 | * because there may have been pages dirtied before our sync |
| 557 | * call, but which had writeout started before we write it out. |
| 558 | * In which case, the inode may not be on the dirty list, but |
| 559 | * we still have to wait for that writeout. |
| 560 | */ |
| 561 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
| 562 | struct address_space *mapping; |
| 563 | |
Wu Fengguang | b6fac63 | 2009-04-02 16:56:34 -0700 | [diff] [blame] | 564 | if (inode->i_state & |
| 565 | (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 566 | continue; |
| 567 | mapping = inode->i_mapping; |
| 568 | if (mapping->nrpages == 0) |
| 569 | continue; |
| 570 | __iget(inode); |
| 571 | spin_unlock(&inode_lock); |
| 572 | /* |
| 573 | * We hold a reference to 'inode' so it couldn't have |
| 574 | * been removed from s_inodes list while we dropped the |
| 575 | * inode_lock. We cannot iput the inode now as we can |
| 576 | * be holding the last reference and we cannot iput it |
| 577 | * under inode_lock. So we keep the reference and iput |
| 578 | * it later. |
| 579 | */ |
| 580 | iput(old_inode); |
| 581 | old_inode = inode; |
| 582 | |
| 583 | filemap_fdatawait(mapping); |
| 584 | |
| 585 | cond_resched(); |
| 586 | |
| 587 | spin_lock(&inode_lock); |
| 588 | } |
| 589 | spin_unlock(&inode_lock); |
| 590 | iput(old_inode); |
| 591 | } else |
| 592 | spin_unlock(&inode_lock); |
| 593 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | return; /* Leave any unwritten inodes on s_io */ |
| 595 | } |
| 596 | |
| 597 | /* |
| 598 | * Start writeback of dirty pagecache data against all unlocked inodes. |
| 599 | * |
| 600 | * Note: |
| 601 | * We don't need to grab a reference to superblock here. If it has non-empty |
| 602 | * ->s_dirty it's hadn't been killed yet and kill_super() won't proceed |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 603 | * past sync_inodes_sb() until the ->s_dirty/s_io/s_more_io lists are all |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | * empty. Since __sync_single_inode() regains inode_lock before it finally moves |
| 605 | * inode from superblock lists we are OK. |
| 606 | * |
| 607 | * If `older_than_this' is non-zero then only flush inodes which have a |
| 608 | * flushtime older than *older_than_this. |
| 609 | * |
| 610 | * If `bdi' is non-zero then we will scan the first inode against each |
| 611 | * superblock until we find the matching ones. One group will be the dirty |
| 612 | * inodes against a filesystem. Then when we hit the dummy blockdev superblock, |
| 613 | * sync_sb_inodes will seekout the blockdev which matches `bdi'. Maybe not |
| 614 | * super-efficient but we're about to do a ton of I/O... |
| 615 | */ |
| 616 | void |
| 617 | writeback_inodes(struct writeback_control *wbc) |
| 618 | { |
| 619 | struct super_block *sb; |
| 620 | |
| 621 | might_sleep(); |
| 622 | spin_lock(&sb_lock); |
| 623 | restart: |
Akinobu Mita | 797074e | 2008-02-06 01:37:08 -0800 | [diff] [blame] | 624 | list_for_each_entry_reverse(sb, &super_blocks, s_list) { |
Fengguang Wu | 08d8e97 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 625 | if (sb_has_dirty_inodes(sb)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | /* we're making our own get_super here */ |
| 627 | sb->s_count++; |
| 628 | spin_unlock(&sb_lock); |
| 629 | /* |
| 630 | * If we can't get the readlock, there's no sense in |
| 631 | * waiting around, most of the time the FS is going to |
| 632 | * be unmounted by the time it is released. |
| 633 | */ |
| 634 | if (down_read_trylock(&sb->s_umount)) { |
Hans Reiser | ae8547b | 2008-05-07 15:48:57 +0300 | [diff] [blame] | 635 | if (sb->s_root) |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 636 | generic_sync_sb_inodes(sb, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | up_read(&sb->s_umount); |
| 638 | } |
| 639 | spin_lock(&sb_lock); |
| 640 | if (__put_super_and_need_restart(sb)) |
| 641 | goto restart; |
| 642 | } |
| 643 | if (wbc->nr_to_write <= 0) |
| 644 | break; |
| 645 | } |
| 646 | spin_unlock(&sb_lock); |
| 647 | } |
| 648 | |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 649 | /** |
| 650 | * writeback_inodes_sb - writeback dirty inodes from given super_block |
| 651 | * @sb: the superblock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | * |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 653 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 654 | * on how many (if any) will be written, and this function does not wait |
| 655 | * for IO completion of submitted IO. The number of pages submitted is |
| 656 | * returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | */ |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 658 | long writeback_inodes_sb(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | { |
| 660 | struct writeback_control wbc = { |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 661 | .sync_mode = WB_SYNC_NONE, |
OGAWA Hirofumi | 111ebb6 | 2006-06-23 02:03:26 -0700 | [diff] [blame] | 662 | .range_start = 0, |
| 663 | .range_end = LLONG_MAX, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | }; |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 665 | unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); |
| 666 | unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); |
| 667 | long nr_to_write; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 669 | nr_to_write = nr_dirty + nr_unstable + |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 670 | (inodes_stat.nr_inodes - inodes_stat.nr_unused); |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 671 | |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 672 | wbc.nr_to_write = nr_to_write; |
| 673 | generic_sync_sb_inodes(sb, &wbc); |
| 674 | return nr_to_write - wbc.nr_to_write; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | } |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame^] | 676 | EXPORT_SYMBOL(writeback_inodes_sb); |
| 677 | |
| 678 | /** |
| 679 | * sync_inodes_sb - sync sb inode pages |
| 680 | * @sb: the superblock |
| 681 | * |
| 682 | * This function writes and waits on any dirty inode belonging to this |
| 683 | * super_block. The number of pages synced is returned. |
| 684 | */ |
| 685 | long sync_inodes_sb(struct super_block *sb) |
| 686 | { |
| 687 | struct writeback_control wbc = { |
| 688 | .sync_mode = WB_SYNC_ALL, |
| 689 | .range_start = 0, |
| 690 | .range_end = LLONG_MAX, |
| 691 | }; |
| 692 | long nr_to_write = LONG_MAX; /* doesn't actually matter */ |
| 693 | |
| 694 | wbc.nr_to_write = nr_to_write; |
| 695 | generic_sync_sb_inodes(sb, &wbc); |
| 696 | return nr_to_write - wbc.nr_to_write; |
| 697 | } |
| 698 | EXPORT_SYMBOL(sync_inodes_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 699 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | /** |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 701 | * write_inode_now - write an inode to disk |
| 702 | * @inode: inode to write to disk |
| 703 | * @sync: whether the write should be synchronous or not |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | * |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 705 | * This function commits an inode to disk immediately if it is dirty. This is |
| 706 | * primarily needed by knfsd. |
| 707 | * |
| 708 | * The caller must either have a ref on the inode or must have set I_WILL_FREE. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | int write_inode_now(struct inode *inode, int sync) |
| 711 | { |
| 712 | int ret; |
| 713 | struct writeback_control wbc = { |
| 714 | .nr_to_write = LONG_MAX, |
Mike Galbraith | 18914b1 | 2008-02-08 04:20:23 -0800 | [diff] [blame] | 715 | .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, |
OGAWA Hirofumi | 111ebb6 | 2006-06-23 02:03:26 -0700 | [diff] [blame] | 716 | .range_start = 0, |
| 717 | .range_end = LLONG_MAX, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | }; |
| 719 | |
| 720 | if (!mapping_cap_writeback_dirty(inode->i_mapping)) |
Andrew Morton | 49364ce | 2005-11-07 00:59:15 -0800 | [diff] [blame] | 721 | wbc.nr_to_write = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | |
| 723 | might_sleep(); |
| 724 | spin_lock(&inode_lock); |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 725 | ret = writeback_single_inode(inode, &wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | spin_unlock(&inode_lock); |
| 727 | if (sync) |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 728 | inode_sync_wait(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | return ret; |
| 730 | } |
| 731 | EXPORT_SYMBOL(write_inode_now); |
| 732 | |
| 733 | /** |
| 734 | * sync_inode - write an inode and its pages to disk. |
| 735 | * @inode: the inode to sync |
| 736 | * @wbc: controls the writeback mode |
| 737 | * |
| 738 | * sync_inode() will write an inode and its pages to disk. It will also |
| 739 | * correctly update the inode on its superblock's dirty inode lists and will |
| 740 | * update inode->i_state. |
| 741 | * |
| 742 | * The caller must have a ref on the inode. |
| 743 | */ |
| 744 | int sync_inode(struct inode *inode, struct writeback_control *wbc) |
| 745 | { |
| 746 | int ret; |
| 747 | |
| 748 | spin_lock(&inode_lock); |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 749 | ret = writeback_single_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | spin_unlock(&inode_lock); |
| 751 | return ret; |
| 752 | } |
| 753 | EXPORT_SYMBOL(sync_inode); |
| 754 | |
| 755 | /** |
| 756 | * generic_osync_inode - flush all dirty data for a given inode to disk |
| 757 | * @inode: inode to write |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 758 | * @mapping: the address_space that should be flushed |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | * @what: what to write and wait upon |
| 760 | * |
| 761 | * This can be called by file_write functions for files which have the |
| 762 | * O_SYNC flag set, to flush dirty writes to disk. |
| 763 | * |
| 764 | * @what is a bitmask, specifying which part of the inode's data should be |
Randy Dunlap | b8887e6 | 2005-11-07 01:01:07 -0800 | [diff] [blame] | 765 | * written and waited upon. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | * |
| 767 | * OSYNC_DATA: i_mapping's dirty data |
| 768 | * OSYNC_METADATA: the buffers at i_mapping->private_list |
| 769 | * OSYNC_INODE: the inode itself |
| 770 | */ |
| 771 | |
| 772 | int generic_osync_inode(struct inode *inode, struct address_space *mapping, int what) |
| 773 | { |
| 774 | int err = 0; |
| 775 | int need_write_inode_now = 0; |
| 776 | int err2; |
| 777 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | if (what & OSYNC_DATA) |
| 779 | err = filemap_fdatawrite(mapping); |
| 780 | if (what & (OSYNC_METADATA|OSYNC_DATA)) { |
| 781 | err2 = sync_mapping_buffers(mapping); |
| 782 | if (!err) |
| 783 | err = err2; |
| 784 | } |
| 785 | if (what & OSYNC_DATA) { |
| 786 | err2 = filemap_fdatawait(mapping); |
| 787 | if (!err) |
| 788 | err = err2; |
| 789 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | |
| 791 | spin_lock(&inode_lock); |
| 792 | if ((inode->i_state & I_DIRTY) && |
| 793 | ((what & OSYNC_INODE) || (inode->i_state & I_DIRTY_DATASYNC))) |
| 794 | need_write_inode_now = 1; |
| 795 | spin_unlock(&inode_lock); |
| 796 | |
| 797 | if (need_write_inode_now) { |
| 798 | err2 = write_inode_now(inode, 1); |
| 799 | if (!err) |
| 800 | err = err2; |
| 801 | } |
| 802 | else |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 803 | inode_sync_wait(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | |
| 805 | return err; |
| 806 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | EXPORT_SYMBOL(generic_osync_inode); |