| /* |
| * fs/fs-writeback.c |
| * |
| * Copyright (C) 2002, Linus Torvalds. |
| * |
| * Contains all the functions related to writing back and waiting |
| * upon dirty inodes against superblocks, and writing back dirty |
| * pages against inodes. ie: data writeback. Writeout of the |
| * inode itself is not handled here. |
| * |
| * 10Apr2002 Andrew Morton |
| * Split out of fs/inode.c |
| * Additions for address_space-based writeback |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| #include <linux/sched.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/writeback.h> |
| #include <linux/blkdev.h> |
| #include <linux/backing-dev.h> |
| #include <linux/buffer_head.h> |
| #include "internal.h" |
| |
| |
| /** |
| * writeback_acquire - attempt to get exclusive writeback access to a device |
| * @bdi: the device's backing_dev_info structure |
| * |
| * It is a waste of resources to have more than one pdflush thread blocked on |
| * a single request queue. Exclusion at the request_queue level is obtained |
| * via a flag in the request_queue's backing_dev_info.state. |
| * |
| * Non-request_queue-backed address_spaces will share default_backing_dev_info, |
| * unless they implement their own. Which is somewhat inefficient, as this |
| * may prevent concurrent writeback against multiple devices. |
| */ |
| static int writeback_acquire(struct backing_dev_info *bdi) |
| { |
| return !test_and_set_bit(BDI_pdflush, &bdi->state); |
| } |
| |
| /** |
| * writeback_in_progress - determine whether there is writeback in progress |
| * @bdi: the device's backing_dev_info structure. |
| * |
| * Determine whether there is writeback in progress against a backing device. |
| */ |
| int writeback_in_progress(struct backing_dev_info *bdi) |
| { |
| return test_bit(BDI_pdflush, &bdi->state); |
| } |
| |
| /** |
| * writeback_release - relinquish exclusive writeback access against a device. |
| * @bdi: the device's backing_dev_info structure |
| */ |
| static void writeback_release(struct backing_dev_info *bdi) |
| { |
| BUG_ON(!writeback_in_progress(bdi)); |
| clear_bit(BDI_pdflush, &bdi->state); |
| } |
| |
| /** |
| * __mark_inode_dirty - internal function |
| * @inode: inode to mark |
| * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) |
| * Mark an inode as dirty. Callers should use mark_inode_dirty or |
| * mark_inode_dirty_sync. |
| * |
| * Put the inode on the super block's dirty list. |
| * |
| * CAREFUL! We mark it dirty unconditionally, but move it onto the |
| * dirty list only if it is hashed or if it refers to a blockdev. |
| * If it was not hashed, it will never be added to the dirty list |
| * even if it is later hashed, as it will have been marked dirty already. |
| * |
| * In short, make sure you hash any inodes _before_ you start marking |
| * them dirty. |
| * |
| * This function *must* be atomic for the I_DIRTY_PAGES case - |
| * set_page_dirty() is called under spinlock in several places. |
| * |
| * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
| * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of |
| * the kernel-internal blockdev inode represents the dirtying time of the |
| * blockdev's pages. This is why for I_DIRTY_PAGES we always use |
| * page->mapping->host, so the page-dirtying time is recorded in the internal |
| * blockdev inode. |
| */ |
| void __mark_inode_dirty(struct inode *inode, int flags) |
| { |
| struct super_block *sb = inode->i_sb; |
| |
| /* |
| * Don't do this for I_DIRTY_PAGES - that doesn't actually |
| * dirty the inode itself |
| */ |
| if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
| if (sb->s_op->dirty_inode) |
| sb->s_op->dirty_inode(inode); |
| } |
| |
| /* |
| * make sure that changes are seen by all cpus before we test i_state |
| * -- mikulas |
| */ |
| smp_mb(); |
| |
| /* avoid the locking if we can */ |
| if ((inode->i_state & flags) == flags) |
| return; |
| |
| if (unlikely(block_dump)) { |
| struct dentry *dentry = NULL; |
| const char *name = "?"; |
| |
| if (!list_empty(&inode->i_dentry)) { |
| dentry = list_entry(inode->i_dentry.next, |
| struct dentry, d_alias); |
| if (dentry && dentry->d_name.name) |
| name = (const char *) dentry->d_name.name; |
| } |
| |
| if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) |
| printk(KERN_DEBUG |
| "%s(%d): dirtied inode %lu (%s) on %s\n", |
| current->comm, task_pid_nr(current), inode->i_ino, |
| name, inode->i_sb->s_id); |
| } |
| |
| spin_lock(&inode_lock); |
| if ((inode->i_state & flags) != flags) { |
| const int was_dirty = inode->i_state & I_DIRTY; |
| |
| inode->i_state |= flags; |
| |
| /* |
| * If the inode is being synced, just update its dirty state. |
| * The unlocker will place the inode on the appropriate |
| * superblock list, based upon its state. |
| */ |
| if (inode->i_state & I_SYNC) |
| goto out; |
| |
| /* |
| * Only add valid (hashed) inodes to the superblock's |
| * dirty list. Add blockdev inodes as well. |
| */ |
| if (!S_ISBLK(inode->i_mode)) { |
| if (hlist_unhashed(&inode->i_hash)) |
| goto out; |
| } |
| if (inode->i_state & (I_FREEING|I_CLEAR)) |
| goto out; |
| |
| /* |
| * If the inode was already on s_dirty/s_io/s_more_io, don't |
| * reposition it (that would break s_dirty time-ordering). |
| */ |
| if (!was_dirty) { |
| inode->dirtied_when = jiffies; |
| list_move(&inode->i_list, &sb->s_dirty); |
| } |
| } |
| out: |
| spin_unlock(&inode_lock); |
| } |
| |
| EXPORT_SYMBOL(__mark_inode_dirty); |
| |
| static int write_inode(struct inode *inode, int sync) |
| { |
| if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) |
| return inode->i_sb->s_op->write_inode(inode, sync); |
| return 0; |
| } |
| |
| /* |
| * Redirty an inode: set its when-it-was dirtied timestamp and move it to the |
| * furthest end of its superblock's dirty-inode list. |
| * |
| * Before stamping the inode's ->dirtied_when, we check to see whether it is |
| * already the most-recently-dirtied inode on the s_dirty list. If that is |
| * the case then the inode must have been redirtied while it was being written |
| * out and we don't reset its dirtied_when. |
| */ |
| static void redirty_tail(struct inode *inode) |
| { |
| struct super_block *sb = inode->i_sb; |
| |
| if (!list_empty(&sb->s_dirty)) { |
| struct inode *tail_inode; |
| |
| tail_inode = list_entry(sb->s_dirty.next, struct inode, i_list); |
| if (!time_after_eq(inode->dirtied_when, |
| tail_inode->dirtied_when)) |
| inode->dirtied_when = jiffies; |
| } |
| list_move(&inode->i_list, &sb->s_dirty); |
| } |
| |
| /* |
| * requeue inode for re-scanning after sb->s_io list is exhausted. |
| */ |
| static void requeue_io(struct inode *inode) |
| { |
| list_move(&inode->i_list, &inode->i_sb->s_more_io); |
| } |
| |
| static void inode_sync_complete(struct inode *inode) |
| { |
| /* |
| * Prevent speculative execution through spin_unlock(&inode_lock); |
| */ |
| smp_mb(); |
| wake_up_bit(&inode->i_state, __I_SYNC); |
| } |
| |
| /* |
| * Move expired dirty inodes from @delaying_queue to @dispatch_queue. |
| */ |
| static void move_expired_inodes(struct list_head *delaying_queue, |
| struct list_head *dispatch_queue, |
| unsigned long *older_than_this) |
| { |
| while (!list_empty(delaying_queue)) { |
| struct inode *inode = list_entry(delaying_queue->prev, |
| struct inode, i_list); |
| if (older_than_this && |
| time_after(inode->dirtied_when, *older_than_this)) |
| break; |
| list_move(&inode->i_list, dispatch_queue); |
| } |
| } |
| |
| /* |
| * Queue all expired dirty inodes for io, eldest first. |
| */ |
| static void queue_io(struct super_block *sb, |
| unsigned long *older_than_this) |
| { |
| list_splice_init(&sb->s_more_io, sb->s_io.prev); |
| move_expired_inodes(&sb->s_dirty, &sb->s_io, older_than_this); |
| } |
| |
| int sb_has_dirty_inodes(struct super_block *sb) |
| { |
| return !list_empty(&sb->s_dirty) || |
| !list_empty(&sb->s_io) || |
| !list_empty(&sb->s_more_io); |
| } |
| EXPORT_SYMBOL(sb_has_dirty_inodes); |
| |
| /* |
| * Write a single inode's dirty pages and inode data out to disk. |
| * If `wait' is set, wait on the writeout. |
| * |
| * The whole writeout design is quite complex and fragile. We want to avoid |
| * starvation of particular inodes when others are being redirtied, prevent |
| * livelocks, etc. |
| * |
| * Called under inode_lock. |
| */ |
| static int |
| __sync_single_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| unsigned dirty; |
| struct address_space *mapping = inode->i_mapping; |
| int wait = wbc->sync_mode == WB_SYNC_ALL; |
| int ret; |
| |
| BUG_ON(inode->i_state & I_SYNC); |
| |
| /* Set I_SYNC, reset I_DIRTY */ |
| dirty = inode->i_state & I_DIRTY; |
| inode->i_state |= I_SYNC; |
| inode->i_state &= ~I_DIRTY; |
| |
| spin_unlock(&inode_lock); |
| |
| ret = do_writepages(mapping, wbc); |
| |
| /* Don't write the inode if only I_DIRTY_PAGES was set */ |
| if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
| int err = write_inode(inode, wait); |
| if (ret == 0) |
| ret = err; |
| } |
| |
| if (wait) { |
| int err = filemap_fdatawait(mapping); |
| if (ret == 0) |
| ret = err; |
| } |
| |
| spin_lock(&inode_lock); |
| inode->i_state &= ~I_SYNC; |
| if (!(inode->i_state & I_FREEING)) { |
| if (!(inode->i_state & I_DIRTY) && |
| mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { |
| /* |
| * We didn't write back all the pages. nfs_writepages() |
| * sometimes bales out without doing anything. Redirty |
| * the inode; Move it from s_io onto s_more_io/s_dirty. |
| */ |
| /* |
| * akpm: if the caller was the kupdate function we put |
| * this inode at the head of s_dirty so it gets first |
| * consideration. Otherwise, move it to the tail, for |
| * the reasons described there. I'm not really sure |
| * how much sense this makes. Presumably I had a good |
| * reasons for doing it this way, and I'd rather not |
| * muck with it at present. |
| */ |
| if (wbc->for_kupdate) { |
| /* |
| * For the kupdate function we move the inode |
| * to s_more_io so it will get more writeout as |
| * soon as the queue becomes uncongested. |
| */ |
| inode->i_state |= I_DIRTY_PAGES; |
| if (wbc->nr_to_write <= 0) { |
| /* |
| * slice used up: queue for next turn |
| */ |
| requeue_io(inode); |
| } else { |
| /* |
| * somehow blocked: retry later |
| */ |
| redirty_tail(inode); |
| } |
| } else { |
| /* |
| * Otherwise fully redirty the inode so that |
| * other inodes on this superblock will get some |
| * writeout. Otherwise heavy writing to one |
| * file would indefinitely suspend writeout of |
| * all the other files. |
| */ |
| inode->i_state |= I_DIRTY_PAGES; |
| redirty_tail(inode); |
| } |
| } else if (inode->i_state & I_DIRTY) { |
| /* |
| * Someone redirtied the inode while were writing back |
| * the pages. |
| */ |
| redirty_tail(inode); |
| } else if (atomic_read(&inode->i_count)) { |
| /* |
| * The inode is clean, inuse |
| */ |
| list_move(&inode->i_list, &inode_in_use); |
| } else { |
| /* |
| * The inode is clean, unused |
| */ |
| list_move(&inode->i_list, &inode_unused); |
| } |
| } |
| inode_sync_complete(inode); |
| return ret; |
| } |
| |
| /* |
| * Write out an inode's dirty pages. Called under inode_lock. Either the |
| * caller has ref on the inode (either via __iget or via syscall against an fd) |
| * or the inode has I_WILL_FREE set (via generic_forget_inode) |
| */ |
| static int |
| __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| wait_queue_head_t *wqh; |
| |
| if (!atomic_read(&inode->i_count)) |
| WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); |
| else |
| WARN_ON(inode->i_state & I_WILL_FREE); |
| |
| if ((wbc->sync_mode != WB_SYNC_ALL) && (inode->i_state & I_SYNC)) { |
| /* |
| * We're skipping this inode because it's locked, and we're not |
| * doing writeback-for-data-integrity. Move it to s_more_io so |
| * that writeback can proceed with the other inodes on s_io. |
| * We'll have another go at writing back this inode when we |
| * completed a full scan of s_io. |
| */ |
| requeue_io(inode); |
| return 0; |
| } |
| |
| /* |
| * It's a data-integrity sync. We must wait. |
| */ |
| if (inode->i_state & I_SYNC) { |
| DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); |
| |
| wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
| do { |
| spin_unlock(&inode_lock); |
| __wait_on_bit(wqh, &wq, inode_wait, |
| TASK_UNINTERRUPTIBLE); |
| spin_lock(&inode_lock); |
| } while (inode->i_state & I_SYNC); |
| } |
| return __sync_single_inode(inode, wbc); |
| } |
| |
| /* |
| * Write out a superblock's list of dirty inodes. A wait will be performed |
| * upon no inodes, all inodes or the final one, depending upon sync_mode. |
| * |
| * If older_than_this is non-NULL, then only write out inodes which |
| * had their first dirtying at a time earlier than *older_than_this. |
| * |
| * If we're a pdlfush thread, then implement pdflush collision avoidance |
| * against the entire list. |
| * |
| * If `bdi' is non-zero then we're being asked to writeback a specific queue. |
| * This function assumes that the blockdev superblock's inodes are backed by |
| * a variety of queues, so all inodes are searched. For other superblocks, |
| * assume that all inodes are backed by the same queue. |
| * |
| * FIXME: this linear search could get expensive with many fileystems. But |
| * how to fix? We need to go from an address_space to all inodes which share |
| * a queue with that address_space. (Easy: have a global "dirty superblocks" |
| * list). |
| * |
| * The inodes to be written are parked on sb->s_io. They are moved back onto |
| * sb->s_dirty as they are selected for writing. This way, none can be missed |
| * on the writer throttling path, and we get decent balancing between many |
| * throttled threads: we don't want them all piling up on inode_sync_wait. |
| */ |
| void generic_sync_sb_inodes(struct super_block *sb, |
| struct writeback_control *wbc) |
| { |
| const unsigned long start = jiffies; /* livelock avoidance */ |
| |
| spin_lock(&inode_lock); |
| if (!wbc->for_kupdate || list_empty(&sb->s_io)) |
| queue_io(sb, wbc->older_than_this); |
| |
| while (!list_empty(&sb->s_io)) { |
| struct inode *inode = list_entry(sb->s_io.prev, |
| struct inode, i_list); |
| struct address_space *mapping = inode->i_mapping; |
| struct backing_dev_info *bdi = mapping->backing_dev_info; |
| long pages_skipped; |
| |
| if (!bdi_cap_writeback_dirty(bdi)) { |
| redirty_tail(inode); |
| if (sb_is_blkdev_sb(sb)) { |
| /* |
| * Dirty memory-backed blockdev: the ramdisk |
| * driver does this. Skip just this inode |
| */ |
| continue; |
| } |
| /* |
| * Dirty memory-backed inode against a filesystem other |
| * than the kernel-internal bdev filesystem. Skip the |
| * entire superblock. |
| */ |
| break; |
| } |
| |
| if (wbc->nonblocking && bdi_write_congested(bdi)) { |
| wbc->encountered_congestion = 1; |
| if (!sb_is_blkdev_sb(sb)) |
| break; /* Skip a congested fs */ |
| requeue_io(inode); |
| continue; /* Skip a congested blockdev */ |
| } |
| |
| if (wbc->bdi && bdi != wbc->bdi) { |
| if (!sb_is_blkdev_sb(sb)) |
| break; /* fs has the wrong queue */ |
| requeue_io(inode); |
| continue; /* blockdev has wrong queue */ |
| } |
| |
| /* Was this inode dirtied after sync_sb_inodes was called? */ |
| if (time_after(inode->dirtied_when, start)) |
| break; |
| |
| /* Is another pdflush already flushing this queue? */ |
| if (current_is_pdflush() && !writeback_acquire(bdi)) |
| break; |
| |
| BUG_ON(inode->i_state & I_FREEING); |
| __iget(inode); |
| pages_skipped = wbc->pages_skipped; |
| __writeback_single_inode(inode, wbc); |
| if (current_is_pdflush()) |
| writeback_release(bdi); |
| if (wbc->pages_skipped != pages_skipped) { |
| /* |
| * writeback is not making progress due to locked |
| * buffers. Skip this inode for now. |
| */ |
| redirty_tail(inode); |
| } |
| spin_unlock(&inode_lock); |
| iput(inode); |
| cond_resched(); |
| spin_lock(&inode_lock); |
| if (wbc->nr_to_write <= 0) { |
| wbc->more_io = 1; |
| break; |
| } |
| if (!list_empty(&sb->s_more_io)) |
| wbc->more_io = 1; |
| } |
| spin_unlock(&inode_lock); |
| return; /* Leave any unwritten inodes on s_io */ |
| } |
| EXPORT_SYMBOL_GPL(generic_sync_sb_inodes); |
| |
| static void sync_sb_inodes(struct super_block *sb, |
| struct writeback_control *wbc) |
| { |
| generic_sync_sb_inodes(sb, wbc); |
| } |
| |
| /* |
| * Start writeback of dirty pagecache data against all unlocked inodes. |
| * |
| * Note: |
| * We don't need to grab a reference to superblock here. If it has non-empty |
| * ->s_dirty it's hadn't been killed yet and kill_super() won't proceed |
| * past sync_inodes_sb() until the ->s_dirty/s_io/s_more_io lists are all |
| * empty. Since __sync_single_inode() regains inode_lock before it finally moves |
| * inode from superblock lists we are OK. |
| * |
| * If `older_than_this' is non-zero then only flush inodes which have a |
| * flushtime older than *older_than_this. |
| * |
| * If `bdi' is non-zero then we will scan the first inode against each |
| * superblock until we find the matching ones. One group will be the dirty |
| * inodes against a filesystem. Then when we hit the dummy blockdev superblock, |
| * sync_sb_inodes will seekout the blockdev which matches `bdi'. Maybe not |
| * super-efficient but we're about to do a ton of I/O... |
| */ |
| void |
| writeback_inodes(struct writeback_control *wbc) |
| { |
| struct super_block *sb; |
| |
| might_sleep(); |
| spin_lock(&sb_lock); |
| restart: |
| list_for_each_entry_reverse(sb, &super_blocks, s_list) { |
| if (sb_has_dirty_inodes(sb)) { |
| /* we're making our own get_super here */ |
| sb->s_count++; |
| spin_unlock(&sb_lock); |
| /* |
| * If we can't get the readlock, there's no sense in |
| * waiting around, most of the time the FS is going to |
| * be unmounted by the time it is released. |
| */ |
| if (down_read_trylock(&sb->s_umount)) { |
| if (sb->s_root) |
| sync_sb_inodes(sb, wbc); |
| up_read(&sb->s_umount); |
| } |
| spin_lock(&sb_lock); |
| if (__put_super_and_need_restart(sb)) |
| goto restart; |
| } |
| if (wbc->nr_to_write <= 0) |
| break; |
| } |
| spin_unlock(&sb_lock); |
| } |
| |
| /* |
| * writeback and wait upon the filesystem's dirty inodes. The caller will |
| * do this in two passes - one to write, and one to wait. |
| * |
| * A finite limit is set on the number of pages which will be written. |
| * To prevent infinite livelock of sys_sync(). |
| * |
| * We add in the number of potentially dirty inodes, because each inode write |
| * can dirty pagecache in the underlying blockdev. |
| */ |
| void sync_inodes_sb(struct super_block *sb, int wait) |
| { |
| struct writeback_control wbc = { |
| .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, |
| .range_start = 0, |
| .range_end = LLONG_MAX, |
| }; |
| unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY); |
| unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); |
| |
| wbc.nr_to_write = nr_dirty + nr_unstable + |
| (inodes_stat.nr_inodes - inodes_stat.nr_unused) + |
| nr_dirty + nr_unstable; |
| wbc.nr_to_write += wbc.nr_to_write / 2; /* Bit more for luck */ |
| sync_sb_inodes(sb, &wbc); |
| } |
| |
| /* |
| * Rather lame livelock avoidance. |
| */ |
| static void set_sb_syncing(int val) |
| { |
| struct super_block *sb; |
| spin_lock(&sb_lock); |
| list_for_each_entry_reverse(sb, &super_blocks, s_list) |
| sb->s_syncing = val; |
| spin_unlock(&sb_lock); |
| } |
| |
| /** |
| * sync_inodes - writes all inodes to disk |
| * @wait: wait for completion |
| * |
| * sync_inodes() goes through each super block's dirty inode list, writes the |
| * inodes out, waits on the writeout and puts the inodes back on the normal |
| * list. |
| * |
| * This is for sys_sync(). fsync_dev() uses the same algorithm. The subtle |
| * part of the sync functions is that the blockdev "superblock" is processed |
| * last. This is because the write_inode() function of a typical fs will |
| * perform no I/O, but will mark buffers in the blockdev mapping as dirty. |
| * What we want to do is to perform all that dirtying first, and then write |
| * back all those inode blocks via the blockdev mapping in one sweep. So the |
| * additional (somewhat redundant) sync_blockdev() calls here are to make |
| * sure that really happens. Because if we call sync_inodes_sb(wait=1) with |
| * outstanding dirty inodes, the writeback goes block-at-a-time within the |
| * filesystem's write_inode(). This is extremely slow. |
| */ |
| static void __sync_inodes(int wait) |
| { |
| struct super_block *sb; |
| |
| spin_lock(&sb_lock); |
| restart: |
| list_for_each_entry(sb, &super_blocks, s_list) { |
| if (sb->s_syncing) |
| continue; |
| sb->s_syncing = 1; |
| sb->s_count++; |
| spin_unlock(&sb_lock); |
| down_read(&sb->s_umount); |
| if (sb->s_root) { |
| sync_inodes_sb(sb, wait); |
| sync_blockdev(sb->s_bdev); |
| } |
| up_read(&sb->s_umount); |
| spin_lock(&sb_lock); |
| if (__put_super_and_need_restart(sb)) |
| goto restart; |
| } |
| spin_unlock(&sb_lock); |
| } |
| |
| void sync_inodes(int wait) |
| { |
| set_sb_syncing(0); |
| __sync_inodes(0); |
| |
| if (wait) { |
| set_sb_syncing(0); |
| __sync_inodes(1); |
| } |
| } |
| |
| /** |
| * write_inode_now - write an inode to disk |
| * @inode: inode to write to disk |
| * @sync: whether the write should be synchronous or not |
| * |
| * This function commits an inode to disk immediately if it is dirty. This is |
| * primarily needed by knfsd. |
| * |
| * The caller must either have a ref on the inode or must have set I_WILL_FREE. |
| */ |
| int write_inode_now(struct inode *inode, int sync) |
| { |
| int ret; |
| struct writeback_control wbc = { |
| .nr_to_write = LONG_MAX, |
| .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, |
| .range_start = 0, |
| .range_end = LLONG_MAX, |
| }; |
| |
| if (!mapping_cap_writeback_dirty(inode->i_mapping)) |
| wbc.nr_to_write = 0; |
| |
| might_sleep(); |
| spin_lock(&inode_lock); |
| ret = __writeback_single_inode(inode, &wbc); |
| spin_unlock(&inode_lock); |
| if (sync) |
| inode_sync_wait(inode); |
| return ret; |
| } |
| EXPORT_SYMBOL(write_inode_now); |
| |
| /** |
| * sync_inode - write an inode and its pages to disk. |
| * @inode: the inode to sync |
| * @wbc: controls the writeback mode |
| * |
| * sync_inode() will write an inode and its pages to disk. It will also |
| * correctly update the inode on its superblock's dirty inode lists and will |
| * update inode->i_state. |
| * |
| * The caller must have a ref on the inode. |
| */ |
| int sync_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| int ret; |
| |
| spin_lock(&inode_lock); |
| ret = __writeback_single_inode(inode, wbc); |
| spin_unlock(&inode_lock); |
| return ret; |
| } |
| EXPORT_SYMBOL(sync_inode); |
| |
| /** |
| * generic_osync_inode - flush all dirty data for a given inode to disk |
| * @inode: inode to write |
| * @mapping: the address_space that should be flushed |
| * @what: what to write and wait upon |
| * |
| * This can be called by file_write functions for files which have the |
| * O_SYNC flag set, to flush dirty writes to disk. |
| * |
| * @what is a bitmask, specifying which part of the inode's data should be |
| * written and waited upon. |
| * |
| * OSYNC_DATA: i_mapping's dirty data |
| * OSYNC_METADATA: the buffers at i_mapping->private_list |
| * OSYNC_INODE: the inode itself |
| */ |
| |
| int generic_osync_inode(struct inode *inode, struct address_space *mapping, int what) |
| { |
| int err = 0; |
| int need_write_inode_now = 0; |
| int err2; |
| |
| if (what & OSYNC_DATA) |
| err = filemap_fdatawrite(mapping); |
| if (what & (OSYNC_METADATA|OSYNC_DATA)) { |
| err2 = sync_mapping_buffers(mapping); |
| if (!err) |
| err = err2; |
| } |
| if (what & OSYNC_DATA) { |
| err2 = filemap_fdatawait(mapping); |
| if (!err) |
| err = err2; |
| } |
| |
| spin_lock(&inode_lock); |
| if ((inode->i_state & I_DIRTY) && |
| ((what & OSYNC_INODE) || (inode->i_state & I_DIRTY_DATASYNC))) |
| need_write_inode_now = 1; |
| spin_unlock(&inode_lock); |
| |
| if (need_write_inode_now) { |
| err2 = write_inode_now(inode, 1); |
| if (!err) |
| err = err2; |
| } |
| else |
| inode_sync_wait(inode); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(generic_osync_inode); |