diff options
| -rw-r--r-- | fs/btrfs/btrfs_inode.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/file.c | 4 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 72 |
3 files changed, 71 insertions, 7 deletions
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index c9a24444ec9..a0cf3e56fe2 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -284,4 +284,6 @@ static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode) &BTRFS_I(inode)->runtime_flags); } +bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end); + #endif diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 8accf94ef22..e46bfaf6cde 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2266,9 +2266,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) if ((!ordered || (ordered->file_offset + ordered->len <= lockstart || ordered->file_offset > lockend)) && - !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart, - lockend, EXTENT_UPTODATE, 0, - cached_state)) { + !btrfs_page_exists_in_range(inode, lockstart, lockend)) { if (ordered) btrfs_put_ordered_extent(ordered); break; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 0b8ce3002cf..a462da1a3e6 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6735,6 +6735,71 @@ out: return ret; } +bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end) +{ + struct radix_tree_root *root = &inode->i_mapping->page_tree; + int found = false; + void **pagep = NULL; + struct page *page = NULL; + int start_idx; + int end_idx; + + start_idx = start >> PAGE_CACHE_SHIFT; + + /* + * end is the last byte in the last page. end == start is legal + */ + end_idx = end >> PAGE_CACHE_SHIFT; + + rcu_read_lock(); + + /* Most of the code in this while loop is lifted from + * find_get_page. It's been modified to begin searching from a + * page and return just the first page found in that range. If the + * found idx is less than or equal to the end idx then we know that + * a page exists. If no pages are found or if those pages are + * outside of the range then we're fine (yay!) */ + while (page == NULL && + radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) { + page = radix_tree_deref_slot(pagep); + if (unlikely(!page)) + break; + + if (radix_tree_exception(page)) { + if (radix_tree_deref_retry(page)) + continue; + /* + * Otherwise, shmem/tmpfs must be storing a swap entry + * here as an exceptional entry: so return it without + * attempting to raise page count. + */ + break; /* TODO: Is this relevant for this use case? */ + } + + if (!page_cache_get_speculative(page)) + continue; + + /* + * Has the page moved? + * This is part of the lockless pagecache protocol. See + * include/linux/pagemap.h for details. + */ + if (unlikely(page != *pagep)) { + page_cache_release(page); + page = NULL; + } + } + + if (page) { + if (page->index <= end_idx) + found = true; + page_cache_release(page); + } + + rcu_read_unlock(); + return found; +} + static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, struct extent_state **cached_state, int writing) { @@ -6759,10 +6824,9 @@ static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, * invalidate needs to happen so that reads after a write do not * get stale data. */ - if (!ordered && (!writing || - !test_range_bit(&BTRFS_I(inode)->io_tree, - lockstart, lockend, EXTENT_UPTODATE, 0, - *cached_state))) + if (!ordered && + (!writing || + !btrfs_page_exists_in_range(inode, lockstart, lockend))) break; unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, |