Btrfs: Fix the unplug_io_fn to grab a consistent copy of page->mapping

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2008-04-22 13:26:47 -04:00
parent e1c4b7451e
commit bcbfce8abd
2 changed files with 22 additions and 7 deletions

View file

@ -936,14 +936,25 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
struct inode *inode; struct inode *inode;
struct extent_map_tree *em_tree; struct extent_map_tree *em_tree;
struct extent_map *em; struct extent_map *em;
struct address_space *mapping;
u64 offset; u64 offset;
/* the generic O_DIRECT read code does this */
if (!page) { if (!page) {
__unplug_io_fn(bdi, page); __unplug_io_fn(bdi, page);
return; 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); offset = page_offset(page);
em_tree = &BTRFS_I(inode)->extent_tree; em_tree = &BTRFS_I(inode)->extent_tree;

View file

@ -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 total = btrfs_super_total_bytes(&root->fs_info->super_copy);
u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy); u64 used = btrfs_super_bytes_used(&root->fs_info->super_copy);
u64 thresh; u64 thresh;
unsigned long flags;
int ret = 0; int ret = 0;
if (for_del) if (for_del)
@ -89,10 +90,10 @@ int btrfs_check_free_space(struct btrfs_root *root, u64 num_required,
do_div(thresh, 100); 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) if (used + root->fs_info->delalloc_bytes + num_required > thresh)
ret = -ENOSPC; ret = -ENOSPC;
spin_unlock(&root->fs_info->delalloc_lock); spin_unlock_irqrestore(&root->fs_info->delalloc_lock, flags);
return ret; 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, int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end,
unsigned long old, unsigned long bits) unsigned long old, unsigned long bits)
{ {
unsigned long flags;
if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root; 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; BTRFS_I(inode)->delalloc_bytes += end - start + 1;
root->fs_info->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; 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)) { if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root; 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) { if (end - start + 1 > root->fs_info->delalloc_bytes) {
printk("warning: delalloc account %Lu %Lu\n", printk("warning: delalloc account %Lu %Lu\n",
end - start + 1, root->fs_info->delalloc_bytes); 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; root->fs_info->delalloc_bytes -= end - start + 1;
BTRFS_I(inode)->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; return 0;
} }