From bcbfce8abd5f8d3f84eab60a9df1ec147f81c34f Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 22 Apr 2008 13:26:47 -0400 Subject: [PATCH] Btrfs: Fix the unplug_io_fn to grab a consistent copy of page->mapping Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 13 ++++++++++++- fs/btrfs/inode.c | 16 ++++++++++------ 2 files changed, 22 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 19c258d2c7e2..1281c393c7e6 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -936,14 +936,25 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) struct inode *inode; struct extent_map_tree *em_tree; struct extent_map *em; + struct address_space *mapping; u64 offset; + /* the generic O_DIRECT read code does this */ if (!page) { __unplug_io_fn(bdi, page); return; } - inode = page->mapping->host; + /* + * page->mapping may change at any time. Get a consistent copy + * and use that for everything below + */ + smp_mb(); + mapping = page->mapping; + if (!mapping) + return; + + inode = mapping->host; offset = page_offset(page); em_tree = &BTRFS_I(inode)->extent_tree; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index abfe86df02d2..d58b4d5a1fef 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -80,6 +80,7 @@ int btrfs_check_free_space(struct btrfs_root *root, u64 num_required, u64 total = btrfs_super_total_bytes(&root->fs_info->super_copy); u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy); u64 thresh; + unsigned long flags; int ret = 0; if (for_del) @@ -89,10 +90,10 @@ int btrfs_check_free_space(struct btrfs_root *root, u64 num_required, do_div(thresh, 100); - spin_lock(&root->fs_info->delalloc_lock); + spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); if (used + root->fs_info->delalloc_bytes + num_required > thresh) ret = -ENOSPC; - spin_unlock(&root->fs_info->delalloc_lock); + spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags); return ret; } @@ -275,12 +276,13 @@ static int run_delalloc_range(struct inode *inode, u64 start, u64 end) int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end, unsigned long old, unsigned long bits) { + unsigned long flags; if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; - spin_lock(&root->fs_info->delalloc_lock); + spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); BTRFS_I(inode)->delalloc_bytes += end - start + 1; root->fs_info->delalloc_bytes += end - start + 1; - spin_unlock(&root->fs_info->delalloc_lock); + spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags); } return 0; } @@ -290,7 +292,9 @@ int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end, { if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; - spin_lock(&root->fs_info->delalloc_lock); + unsigned long flags; + + spin_lock_irqsave(&root->fs_info->delalloc_lock, flags); if (end - start + 1 > root->fs_info->delalloc_bytes) { printk("warning: delalloc account %Lu %Lu\n", end - start + 1, root->fs_info->delalloc_bytes); @@ -300,7 +304,7 @@ int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end, root->fs_info->delalloc_bytes -= end - start + 1; BTRFS_I(inode)->delalloc_bytes -= end - start + 1; } - spin_unlock(&root->fs_info->delalloc_lock); + spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags); } return 0; }