From 2f120c05e67ae34c93786b1050c6828904314429 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 10 Nov 2011 20:45:05 -0500 Subject: Btrfs: only map pages if we know we need them when reading the space cache People have been running into a warning when loading space cache because the page is already mapped when trying to read in a bitmap. The way we read in entries and pages is kind of convoluted, so fix it so that io_ctl_read_entry maps the entries if it needs to, and if it hits the end of the page it simply unmaps the page. That way we can unconditionally unmap the io_ctl before reading in the bitmap and we should stop hitting these warnings. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/free-space-cache.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 7a15fcfb3e1f..181760f9d2ab 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -537,6 +537,13 @@ static int io_ctl_read_entry(struct io_ctl *io_ctl, struct btrfs_free_space *entry, u8 *type) { struct btrfs_free_space_entry *e; + int ret; + + if (!io_ctl->cur) { + ret = io_ctl_check_crc(io_ctl, io_ctl->index); + if (ret) + return ret; + } e = io_ctl->cur; entry->offset = le64_to_cpu(e->offset); @@ -550,10 +557,7 @@ static int io_ctl_read_entry(struct io_ctl *io_ctl, io_ctl_unmap_page(io_ctl); - if (io_ctl->index >= io_ctl->num_pages) - return 0; - - return io_ctl_check_crc(io_ctl, io_ctl->index); + return 0; } static int io_ctl_read_bitmap(struct io_ctl *io_ctl, @@ -561,9 +565,6 @@ static int io_ctl_read_bitmap(struct io_ctl *io_ctl, { int ret; - if (io_ctl->cur && io_ctl->cur != io_ctl->orig) - io_ctl_unmap_page(io_ctl); - ret = io_ctl_check_crc(io_ctl, io_ctl->index); if (ret) return ret; @@ -699,6 +700,8 @@ int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, num_entries--; } + io_ctl_unmap_page(&io_ctl); + /* * We add the bitmaps at the end of the entries in order that * the bitmap entries are added to the cache. -- cgit v1.2.2