ext4: handle writeback of inodes which are being freed

[pandora-kernel.git] / fs / ext4 / page-io.c

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 46a7d6a..a24c8cc 100644 (file)
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -32,8 +32,14 @@
 
 static struct kmem_cache *io_page_cachep, *io_end_cachep;
 
+#define WQ_HASH_SZ             37
+#define to_ioend_wq(v) (&ioend_wq[((unsigned long)v) % WQ_HASH_SZ])
+static wait_queue_head_t ioend_wq[WQ_HASH_SZ];
+
 int __init ext4_init_pageio(void)
 {
+       int i;
+
        io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT);
        if (io_page_cachep == NULL)
                return -ENOMEM;
@@ -42,6 +48,8 @@ int __init ext4_init_pageio(void)
                kmem_cache_destroy(io_page_cachep);
                return -ENOMEM;
        }
+       for (i = 0; i < WQ_HASH_SZ; i++)
+               init_waitqueue_head(&ioend_wq[i]);
 
        return 0;
 }
@@ -52,9 +60,17 @@ void ext4_exit_pageio(void)
        kmem_cache_destroy(io_page_cachep);
 }
 
+void ext4_ioend_wait(struct inode *inode)
+{
+       wait_queue_head_t *wq = to_ioend_wq(inode);
+
+       wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0));
+}
+
 void ext4_free_io_end(ext4_io_end_t *io)
 {
        int i;
+       wait_queue_head_t *wq;
 
        BUG_ON(!io);
        if (io->page)
@@ -69,7 +85,10 @@ void ext4_free_io_end(ext4_io_end_t *io)
                }
        }
        io->num_io_pages = 0;
-       iput(io->inode);
+       wq = to_ioend_wq(io->inode);
+       if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count) &&
+           waitqueue_active(wq))
+               wake_up_all(wq);
        kmem_cache_free(io_end_cachep, io);
 }
 
@@ -142,8 +161,8 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
        io = kmem_cache_alloc(io_end_cachep, flags);
        if (io) {
                memset(io, 0, sizeof(*io));
-               io->inode = igrab(inode);
-               BUG_ON(!io->inode);
+               atomic_inc(&EXT4_I(inode)->i_ioend_count);
+               io->inode = inode;
                INIT_WORK(&io->work, ext4_end_io_work);
                INIT_LIST_HEAD(&io->list);
        }
@@ -171,35 +190,15 @@ static void ext4_end_bio(struct bio *bio, int error)
        struct workqueue_struct *wq;
        struct inode *inode;
        unsigned long flags;
-       ext4_fsblk_t err_block;
        int i;
 
        BUG_ON(!io_end);
-       inode = io_end->inode;
        bio->bi_private = NULL;
        bio->bi_end_io = NULL;
        if (test_bit(BIO_UPTODATE, &bio->bi_flags))
                error = 0;
-       err_block = bio->bi_sector >> (inode->i_blkbits - 9);
        bio_put(bio);
 
-       if (!(inode->i_sb->s_flags & MS_ACTIVE)) {
-               pr_err("sb umounted, discard end_io request for inode %lu\n",
-                       io_end->inode->i_ino);
-               ext4_free_io_end(io_end);
-               return;
-       }
-
-       if (error) {
-               io_end->flag |= EXT4_IO_END_ERROR;
-               ext4_warning(inode->i_sb, "I/O error writing to inode %lu "
-                            "(offset %llu size %ld starting block %llu)",
-                            inode->i_ino,
-                            (unsigned long long) io_end->offset,
-                            (long) io_end->size,
-                            (unsigned long long) err_block);
-       }
-
        for (i = 0; i < io_end->num_io_pages; i++) {
                struct page *page = io_end->pages[i]->p_page;
                struct buffer_head *bh, *head;
@@ -254,8 +253,19 @@ static void ext4_end_bio(struct bio *bio, int error)
                if (!partial_write)
                        SetPageUptodate(page);
        }
-
        io_end->num_io_pages = 0;
+       inode = io_end->inode;
+
+       if (error) {
+               io_end->flag |= EXT4_IO_END_ERROR;
+               ext4_warning(inode->i_sb, "I/O error writing to inode %lu "
+                            "(offset %llu size %ld starting block %llu)",
+                            inode->i_ino,
+                            (unsigned long long) io_end->offset,
+                            (long) io_end->size,
+                            (unsigned long long)
+                            bio->bi_sector >> (inode->i_blkbits - 9));
+       }
 
        /* Add the io_end to per-inode completed io list*/
        spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
@@ -305,7 +315,6 @@ static int io_submit_init(struct ext4_io_submit *io,
        bio->bi_private = io->io_end = io_end;
        bio->bi_end_io = ext4_end_bio;
 
-       io_end->inode = inode;
        io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh);
 
        io->io_bio = bio;