diff options
Diffstat (limited to 'fs/btrfs/subpage.c')
| -rw-r--r-- | fs/btrfs/subpage.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index 7d72eaf5f972..640bcd21bf28 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -3,6 +3,7 @@ #include <linux/slab.h> #include "ctree.h" #include "subpage.h" +#include "btrfs_inode.h" /* * Subpage (sectorsize < PAGE_SIZE) support overview: @@ -185,12 +186,10 @@ void btrfs_subpage_start_reader(const struct btrfs_fs_info *fs_info, { struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; const int nbits = len >> fs_info->sectorsize_bits; - int ret; btrfs_subpage_assert(fs_info, page, start, len); - ret = atomic_add_return(nbits, &subpage->readers); - ASSERT(ret == nbits); + atomic_add(nbits, &subpage->readers); } void btrfs_subpage_end_reader(const struct btrfs_fs_info *fs_info, @@ -198,10 +197,22 @@ void btrfs_subpage_end_reader(const struct btrfs_fs_info *fs_info, { struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private; const int nbits = len >> fs_info->sectorsize_bits; + bool is_data; + bool last; btrfs_subpage_assert(fs_info, page, start, len); + is_data = is_data_inode(page->mapping->host); ASSERT(atomic_read(&subpage->readers) >= nbits); - if (atomic_sub_and_test(nbits, &subpage->readers)) + last = atomic_sub_and_test(nbits, &subpage->readers); + + /* + * For data we need to unlock the page if the last read has finished. + * + * And please don't replace @last with atomic_sub_and_test() call + * inside if () condition. + * As we want the atomic_sub_and_test() to be always executed. + */ + if (is_data && last) unlock_page(page); } |