diff options
| -rw-r--r-- | fs/dax.c | 138 |
1 files changed, 69 insertions, 69 deletions
@@ -121,6 +121,31 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo } /* + * We do not necessarily hold the mapping->tree_lock when we call this + * function so it is possible that 'entry' is no longer a valid item in the + * radix tree. This is okay because all we really need to do is to find the + * correct waitqueue where tasks might be waiting for that old 'entry' and + * wake them. + */ +void dax_wake_mapping_entry_waiter(struct address_space *mapping, + pgoff_t index, void *entry, bool wake_all) +{ + struct exceptional_entry_key key; + wait_queue_head_t *wq; + + wq = dax_entry_waitqueue(mapping, index, entry, &key); + + /* + * Checking for locked entry and prepare_to_wait_exclusive() happens + * under mapping->tree_lock, ditto for entry handling in our callers. + * So at this point all tasks that could have seen our entry locked + * must be in the waitqueue and the following check will see them. + */ + if (waitqueue_active(wq)) + __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); +} + +/* * Check whether the given slot is locked. The function must be called with * mapping->tree_lock held */ @@ -392,31 +417,6 @@ restart: return entry; } -/* - * We do not necessarily hold the mapping->tree_lock when we call this - * function so it is possible that 'entry' is no longer a valid item in the - * radix tree. This is okay because all we really need to do is to find the - * correct waitqueue where tasks might be waiting for that old 'entry' and - * wake them. - */ -void dax_wake_mapping_entry_waiter(struct address_space *mapping, - pgoff_t index, void *entry, bool wake_all) -{ - struct exceptional_entry_key key; - wait_queue_head_t *wq; - - wq = dax_entry_waitqueue(mapping, index, entry, &key); - - /* - * Checking for locked entry and prepare_to_wait_exclusive() happens - * under mapping->tree_lock, ditto for entry handling in our callers. - * So at this point all tasks that could have seen our entry locked - * must be in the waitqueue and the following check will see them. - */ - if (waitqueue_active(wq)) - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); -} - static int __dax_invalidate_mapping_entry(struct address_space *mapping, pgoff_t index, bool trunc) { @@ -468,50 +468,6 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, return __dax_invalidate_mapping_entry(mapping, index, false); } -/* - * The user has performed a load from a hole in the file. Allocating - * a new page in the file would cause excessive storage usage for - * workloads with sparse files. We allocate a page cache page instead. - * We'll kick it out of the page cache if it's ever written to, - * otherwise it will simply fall out of the page cache under memory - * pressure without ever having been dirtied. - */ -static int dax_load_hole(struct address_space *mapping, void **entry, - struct vm_fault *vmf) -{ - struct inode *inode = mapping->host; - struct page *page; - int ret; - - /* Hole page already exists? Return it... */ - if (!radix_tree_exceptional_entry(*entry)) { - page = *entry; - goto finish_fault; - } - - /* This will replace locked radix tree entry with a hole page */ - page = find_or_create_page(mapping, vmf->pgoff, - vmf->gfp_mask | __GFP_ZERO); - if (!page) { - ret = VM_FAULT_OOM; - goto out; - } - -finish_fault: - vmf->page = page; - ret = finish_fault(vmf); - vmf->page = NULL; - *entry = page; - if (!ret) { - /* Grab reference for PTE that is now referencing the page */ - get_page(page); - ret = VM_FAULT_NOPAGE; - } -out: - trace_dax_load_hole(inode, vmf, ret); - return ret; -} - static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, size_t size, struct page *to, unsigned long vaddr) @@ -941,6 +897,50 @@ int dax_pfn_mkwrite(struct vm_fault *vmf) } EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); +/* + * The user has performed a load from a hole in the file. Allocating + * a new page in the file would cause excessive storage usage for + * workloads with sparse files. We allocate a page cache page instead. + * We'll kick it out of the page cache if it's ever written to, + * otherwise it will simply fall out of the page cache under memory + * pressure without ever having been dirtied. + */ +static int dax_load_hole(struct address_space *mapping, void **entry, + struct vm_fault *vmf) +{ + struct inode *inode = mapping->host; + struct page *page; + int ret; + + /* Hole page already exists? Return it... */ + if (!radix_tree_exceptional_entry(*entry)) { + page = *entry; + goto finish_fault; + } + + /* This will replace locked radix tree entry with a hole page */ + page = find_or_create_page(mapping, vmf->pgoff, + vmf->gfp_mask | __GFP_ZERO); + if (!page) { + ret = VM_FAULT_OOM; + goto out; + } + +finish_fault: + vmf->page = page; + ret = finish_fault(vmf); + vmf->page = NULL; + *entry = page; + if (!ret) { + /* Grab reference for PTE that is now referencing the page */ + get_page(page); + ret = VM_FAULT_NOPAGE; + } +out: + trace_dax_load_hole(inode, vmf, ret); + return ret; +} + static bool dax_range_is_aligned(struct block_device *bdev, unsigned int offset, unsigned int length) { |