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mm/filemap.c
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/* * linux/mm/filemap.c * * Copyright (C) 1994-1999 Linus Torvalds */ /* * This file handles the generic file mmap semantics used by * most "normal" filesystems (but you don't /have/ to use this: * the NFS filesystem used to do this differently, for example) */ |
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#include <linux/export.h> |
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#include <linux/compiler.h> #include <linux/fs.h> |
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#include <linux/uaccess.h> |
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#include <linux/aio.h> |
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#include <linux/capability.h> |
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#include <linux/kernel_stat.h> |
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#include <linux/gfp.h> |
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#include <linux/mm.h> #include <linux/swap.h> #include <linux/mman.h> #include <linux/pagemap.h> #include <linux/file.h> #include <linux/uio.h> #include <linux/hash.h> #include <linux/writeback.h> |
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#include <linux/backing-dev.h> |
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#include <linux/pagevec.h> #include <linux/blkdev.h> #include <linux/security.h> #include <linux/syscalls.h> |
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#include <linux/cpuset.h> |
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#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */ |
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#include <linux/memcontrol.h> |
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#include <linux/cleancache.h> |
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#include "internal.h" |
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/* |
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* FIXME: remove all knowledge of the buffer layer from the core VM */ |
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#include <linux/buffer_head.h> /* for try_to_free_buffers */ |
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#include <asm/mman.h> /* * Shared mappings implemented 30.11.1994. It's not fully working yet, * though. * * Shared mappings now work. 15.8.1995 Bruno. * * finished 'unifying' the page and buffer cache and SMP-threaded the * page-cache, 21.05.1999, Ingo Molnar <mingo@redhat.com> * * SMP-threaded pagemap-LRU 1999, Andrea Arcangeli <andrea@suse.de> */ /* * Lock ordering: * |
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* ->i_mmap_mutex (truncate_pagecache) |
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* ->private_lock (__free_pte->__set_page_dirty_buffers) |
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* ->swap_lock (exclusive_swap_page, others) * ->mapping->tree_lock |
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* |
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* ->i_mutex |
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* ->i_mmap_mutex (truncate->unmap_mapping_range) |
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* * ->mmap_sem |
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* ->i_mmap_mutex |
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* ->page_table_lock or pte_lock (various, mainly in memory.c) |
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* ->mapping->tree_lock (arch-dependent flush_dcache_mmap_lock) * * ->mmap_sem * ->lock_page (access_process_vm) * |
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* ->i_mutex (generic_file_buffered_write) * ->mmap_sem (fault_in_pages_readable->do_page_fault) |
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* |
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* bdi->wb.list_lock |
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* sb_lock (fs/fs-writeback.c) |
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* ->mapping->tree_lock (__sync_single_inode) * |
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* ->i_mmap_mutex |
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* ->anon_vma.lock (vma_adjust) * * ->anon_vma.lock |
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* ->page_table_lock or pte_lock (anon_vma_prepare and various) |
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* |
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* ->page_table_lock or pte_lock |
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* ->swap_lock (try_to_unmap_one) |
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* ->private_lock (try_to_unmap_one) * ->tree_lock (try_to_unmap_one) * ->zone.lru_lock (follow_page->mark_page_accessed) |
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* ->zone.lru_lock (check_pte_range->isolate_lru_page) |
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* ->private_lock (page_remove_rmap->set_page_dirty) * ->tree_lock (page_remove_rmap->set_page_dirty) |
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* bdi.wb->list_lock (page_remove_rmap->set_page_dirty) |
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* ->inode->i_lock (page_remove_rmap->set_page_dirty) |
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* bdi.wb->list_lock (zap_pte_range->set_page_dirty) |
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* ->inode->i_lock (zap_pte_range->set_page_dirty) |
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* ->private_lock (zap_pte_range->__set_page_dirty_buffers) * |
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* (code doesn't rely on that order, so you could switch it around) * ->tasklist_lock (memory_failure, collect_procs_ao) |
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* ->i_mmap_mutex |
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*/ /* |
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* Delete a page from the page cache and free it. Caller has to make |
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* sure the page is locked and that nobody else uses it - or that usage |
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* is safe. The caller must hold the mapping's tree_lock. |
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*/ |
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void __delete_from_page_cache(struct page *page) |
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{ struct address_space *mapping = page->mapping; |
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/* * if we're uptodate, flush out into the cleancache, otherwise * invalidate any existing cleancache entries. We can't leave * stale data around in the cleancache once our page is gone */ if (PageUptodate(page) && PageMappedToDisk(page)) cleancache_put_page(page); else cleancache_flush_page(mapping, page); |
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radix_tree_delete(&mapping->page_tree, page->index); page->mapping = NULL; |
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/* Leave page->index set: truncation lookup relies upon it */ |
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mapping->nrpages--; |
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__dec_zone_page_state(page, NR_FILE_PAGES); |
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if (PageSwapBacked(page)) __dec_zone_page_state(page, NR_SHMEM); |
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BUG_ON(page_mapped(page)); |
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/* * Some filesystems seem to re-dirty the page even after * the VM has canceled the dirty bit (eg ext3 journaling). * * Fix it up by doing a final dirty accounting check after * having removed the page entirely. */ if (PageDirty(page) && mapping_cap_account_dirty(mapping)) { dec_zone_page_state(page, NR_FILE_DIRTY); dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE); } |
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} |
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/** * delete_from_page_cache - delete page from page cache * @page: the page which the kernel is trying to remove from page cache * * This must be called only on pages that have been verified to be in the page * cache and locked. It will never put the page into the free list, the caller * has a reference on the page. */ void delete_from_page_cache(struct page *page) |
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{ struct address_space *mapping = page->mapping; |
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void (*freepage)(struct page *); |
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|
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BUG_ON(!PageLocked(page)); |
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|
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freepage = mapping->a_ops->freepage; |
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spin_lock_irq(&mapping->tree_lock); |
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__delete_from_page_cache(page); |
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spin_unlock_irq(&mapping->tree_lock); |
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mem_cgroup_uncharge_cache_page(page); |
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if (freepage) freepage(page); |
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page_cache_release(page); } EXPORT_SYMBOL(delete_from_page_cache); |
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static int sleep_on_page(void *word) |
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{ |
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io_schedule(); return 0; } |
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static int sleep_on_page_killable(void *word) |
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{ |
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sleep_on_page(word); |
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return fatal_signal_pending(current) ? -EINTR : 0; } |
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/** |
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* __filemap_fdatawrite_range - start writeback on mapping dirty pages in range |
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* @mapping: address space structure to write * @start: offset in bytes where the range starts |
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* @end: offset in bytes where the range ends (inclusive) |
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* @sync_mode: enable synchronous operation |
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* |
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* Start writeback against all of a mapping's dirty pages that lie * within the byte offsets <start, end> inclusive. * |
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* If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as |
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* opposed to a regular memory cleansing writeback. The difference between |
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* these two operations is that if a dirty page/buffer is encountered, it must * be waited upon, and not just skipped over. */ |
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int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, loff_t end, int sync_mode) |
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{ int ret; struct writeback_control wbc = { .sync_mode = sync_mode, |
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.nr_to_write = LONG_MAX, |
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.range_start = start, .range_end = end, |
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}; if (!mapping_cap_writeback_dirty(mapping)) return 0; ret = do_writepages(mapping, &wbc); return ret; } static inline int __filemap_fdatawrite(struct address_space *mapping, int sync_mode) { |
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return __filemap_fdatawrite_range(mapping, 0, LLONG_MAX, sync_mode); |
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} int filemap_fdatawrite(struct address_space *mapping) { return __filemap_fdatawrite(mapping, WB_SYNC_ALL); } EXPORT_SYMBOL(filemap_fdatawrite); |
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int filemap_fdatawrite_range(struct address_space *mapping, loff_t start, |
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loff_t end) |
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{ return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_ALL); } |
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EXPORT_SYMBOL(filemap_fdatawrite_range); |
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|
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/** * filemap_flush - mostly a non-blocking flush * @mapping: target address_space * |
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* This is a mostly non-blocking flush. Not suitable for data-integrity * purposes - I/O may not be started against all dirty pages. */ int filemap_flush(struct address_space *mapping) { return __filemap_fdatawrite(mapping, WB_SYNC_NONE); } EXPORT_SYMBOL(filemap_flush); |
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/** |
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* filemap_fdatawait_range - wait for writeback to complete * @mapping: address space structure to wait for * @start_byte: offset in bytes where the range starts * @end_byte: offset in bytes where the range ends (inclusive) |
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* |
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* Walk the list of under-writeback pages of the given address space * in the given range and wait for all of them. |
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*/ |
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int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte, loff_t end_byte) |
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{ |
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pgoff_t index = start_byte >> PAGE_CACHE_SHIFT; pgoff_t end = end_byte >> PAGE_CACHE_SHIFT; |
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struct pagevec pvec; int nr_pages; int ret = 0; |
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|
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if (end_byte < start_byte) |
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return 0; pagevec_init(&pvec, 0); |
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while ((index <= end) && (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_WRITEBACK, min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1)) != 0) { unsigned i; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; /* until radix tree lookup accepts end_index */ if (page->index > end) continue; wait_on_page_writeback(page); |
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if (TestClearPageError(page)) |
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ret = -EIO; } pagevec_release(&pvec); cond_resched(); } /* Check for outstanding write errors */ if (test_and_clear_bit(AS_ENOSPC, &mapping->flags)) ret = -ENOSPC; if (test_and_clear_bit(AS_EIO, &mapping->flags)) ret = -EIO; return ret; } |
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EXPORT_SYMBOL(filemap_fdatawait_range); /** |
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* filemap_fdatawait - wait for all under-writeback pages to complete |
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* @mapping: address space structure to wait for |
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* * Walk the list of under-writeback pages of the given address space * and wait for all of them. |
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*/ int filemap_fdatawait(struct address_space *mapping) { loff_t i_size = i_size_read(mapping->host); if (i_size == 0) return 0; |
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return filemap_fdatawait_range(mapping, 0, i_size - 1); |
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} EXPORT_SYMBOL(filemap_fdatawait); int filemap_write_and_wait(struct address_space *mapping) { |
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int err = 0; |
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if (mapping->nrpages) { |
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err = filemap_fdatawrite(mapping); /* * Even if the above returned error, the pages may be * written partially (e.g. -ENOSPC), so we wait for it. * But the -EIO is special case, it may indicate the worst * thing (e.g. bug) happened, so we avoid waiting for it. */ if (err != -EIO) { int err2 = filemap_fdatawait(mapping); if (!err) err = err2; } |
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} |
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return err; |
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} |
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EXPORT_SYMBOL(filemap_write_and_wait); |
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|
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/** * filemap_write_and_wait_range - write out & wait on a file range * @mapping: the address_space for the pages * @lstart: offset in bytes where the range starts * @lend: offset in bytes where the range ends (inclusive) * |
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* Write out and wait upon file offsets lstart->lend, inclusive. * * Note that `lend' is inclusive (describes the last byte to be written) so * that this function can be used to write to the very end-of-file (end = -1). */ |
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int filemap_write_and_wait_range(struct address_space *mapping, loff_t lstart, loff_t lend) { |
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int err = 0; |
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if (mapping->nrpages) { |
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err = __filemap_fdatawrite_range(mapping, lstart, lend, WB_SYNC_ALL); /* See comment of filemap_write_and_wait() */ if (err != -EIO) { |
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int err2 = filemap_fdatawait_range(mapping, lstart, lend); |
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if (!err) err = err2; } |
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} |
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return err; |
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} |
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EXPORT_SYMBOL(filemap_write_and_wait_range); |
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|
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/** |
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* replace_page_cache_page - replace a pagecache page with a new one * @old: page to be replaced * @new: page to replace with * @gfp_mask: allocation mode * * This function replaces a page in the pagecache with a new one. On * success it acquires the pagecache reference for the new page and * drops it for the old page. Both the old and new pages must be * locked. This function does not add the new page to the LRU, the * caller must do that. * * The remove + add is atomic. The only way this function can fail is * memory allocation failure. */ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) { int error; struct mem_cgroup *memcg = NULL; VM_BUG_ON(!PageLocked(old)); VM_BUG_ON(!PageLocked(new)); VM_BUG_ON(new->mapping); /* * This is not page migration, but prepare_migration and * end_migration does enough work for charge replacement. * * In the longer term we probably want a specialized function * for moving the charge from old to new in a more efficient * manner. */ error = mem_cgroup_prepare_migration(old, new, &memcg, gfp_mask); if (error) return error; error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM); if (!error) { struct address_space *mapping = old->mapping; void (*freepage)(struct page *); pgoff_t offset = old->index; freepage = mapping->a_ops->freepage; page_cache_get(new); new->mapping = mapping; new->index = offset; spin_lock_irq(&mapping->tree_lock); |
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__delete_from_page_cache(old); |
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error = radix_tree_insert(&mapping->page_tree, offset, new); BUG_ON(error); mapping->nrpages++; __inc_zone_page_state(new, NR_FILE_PAGES); if (PageSwapBacked(new)) __inc_zone_page_state(new, NR_SHMEM); spin_unlock_irq(&mapping->tree_lock); radix_tree_preload_end(); if (freepage) freepage(old); page_cache_release(old); mem_cgroup_end_migration(memcg, old, new, true); } else { mem_cgroup_end_migration(memcg, old, new, false); } return error; } EXPORT_SYMBOL_GPL(replace_page_cache_page); /** |
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* add_to_page_cache_locked - add a locked page to the pagecache |
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* @page: page to add * @mapping: the page's address_space * @offset: page index * @gfp_mask: page allocation mode * |
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* This function is used to add a page to the pagecache. It must be locked. |
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* This function does not add the page to the LRU. The caller must do that. */ |
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int add_to_page_cache_locked(struct page *page, struct address_space *mapping, |
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449 |
pgoff_t offset, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
450 |
{ |
e286781d5 mm: speculative p... |
451 452 453 |
int error; VM_BUG_ON(!PageLocked(page)); |
31475dd61 mm: a few small u... |
454 |
VM_BUG_ON(PageSwapBacked(page)); |
e286781d5 mm: speculative p... |
455 456 |
error = mem_cgroup_cache_charge(page, current->mm, |
2c26fdd70 memcg: revert gfp... |
457 |
gfp_mask & GFP_RECLAIM_MASK); |
35c754d79 memory controller... |
458 459 |
if (error) goto out; |
1da177e4c Linux-2.6.12-rc2 |
460 |
|
35c754d79 memory controller... |
461 |
error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM); |
1da177e4c Linux-2.6.12-rc2 |
462 |
if (error == 0) { |
e286781d5 mm: speculative p... |
463 464 465 |
page_cache_get(page); page->mapping = mapping; page->index = offset; |
19fd62312 mm: spinlock tree... |
466 |
spin_lock_irq(&mapping->tree_lock); |
1da177e4c Linux-2.6.12-rc2 |
467 |
error = radix_tree_insert(&mapping->page_tree, offset, page); |
e286781d5 mm: speculative p... |
468 |
if (likely(!error)) { |
1da177e4c Linux-2.6.12-rc2 |
469 |
mapping->nrpages++; |
347ce434d [PATCH] zoned vm ... |
470 |
__inc_zone_page_state(page, NR_FILE_PAGES); |
e767e0561 memcg: fix deadlo... |
471 |
spin_unlock_irq(&mapping->tree_lock); |
e286781d5 mm: speculative p... |
472 473 |
} else { page->mapping = NULL; |
b85e0effd mm: consistent tr... |
474 |
/* Leave page->index set: truncation relies upon it */ |
e767e0561 memcg: fix deadlo... |
475 |
spin_unlock_irq(&mapping->tree_lock); |
69029cd55 memcg: remove ref... |
476 |
mem_cgroup_uncharge_cache_page(page); |
e286781d5 mm: speculative p... |
477 478 |
page_cache_release(page); } |
1da177e4c Linux-2.6.12-rc2 |
479 |
radix_tree_preload_end(); |
35c754d79 memory controller... |
480 |
} else |
69029cd55 memcg: remove ref... |
481 |
mem_cgroup_uncharge_cache_page(page); |
8a9f3ccd2 Memory controller... |
482 |
out: |
1da177e4c Linux-2.6.12-rc2 |
483 484 |
return error; } |
e286781d5 mm: speculative p... |
485 |
EXPORT_SYMBOL(add_to_page_cache_locked); |
1da177e4c Linux-2.6.12-rc2 |
486 487 |
int add_to_page_cache_lru(struct page *page, struct address_space *mapping, |
6daa0e286 [PATCH] gfp_t: mm... |
488 |
pgoff_t offset, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
489 |
{ |
4f98a2fee vmscan: split LRU... |
490 |
int ret; |
4f98a2fee vmscan: split LRU... |
491 |
ret = add_to_page_cache(page, mapping, offset, gfp_mask); |
31475dd61 mm: a few small u... |
492 493 |
if (ret == 0) lru_cache_add_file(page); |
1da177e4c Linux-2.6.12-rc2 |
494 495 |
return ret; } |
18bc0bbd1 Staging: pohmelfs... |
496 |
EXPORT_SYMBOL_GPL(add_to_page_cache_lru); |
1da177e4c Linux-2.6.12-rc2 |
497 |
|
44110fe38 [PATCH] cpuset me... |
498 |
#ifdef CONFIG_NUMA |
2ae88149a [PATCH] mm: clean... |
499 |
struct page *__page_cache_alloc(gfp_t gfp) |
44110fe38 [PATCH] cpuset me... |
500 |
{ |
c0ff7453b cpuset,mm: fix no... |
501 502 |
int n; struct page *page; |
44110fe38 [PATCH] cpuset me... |
503 |
if (cpuset_do_page_mem_spread()) { |
c0ff7453b cpuset,mm: fix no... |
504 505 506 507 508 |
get_mems_allowed(); n = cpuset_mem_spread_node(); page = alloc_pages_exact_node(n, gfp, 0); put_mems_allowed(); return page; |
44110fe38 [PATCH] cpuset me... |
509 |
} |
2ae88149a [PATCH] mm: clean... |
510 |
return alloc_pages(gfp, 0); |
44110fe38 [PATCH] cpuset me... |
511 |
} |
2ae88149a [PATCH] mm: clean... |
512 |
EXPORT_SYMBOL(__page_cache_alloc); |
44110fe38 [PATCH] cpuset me... |
513 |
#endif |
1da177e4c Linux-2.6.12-rc2 |
514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 |
/* * In order to wait for pages to become available there must be * waitqueues associated with pages. By using a hash table of * waitqueues where the bucket discipline is to maintain all * waiters on the same queue and wake all when any of the pages * become available, and for the woken contexts to check to be * sure the appropriate page became available, this saves space * at a cost of "thundering herd" phenomena during rare hash * collisions. */ static wait_queue_head_t *page_waitqueue(struct page *page) { const struct zone *zone = page_zone(page); return &zone->wait_table[hash_ptr(page, zone->wait_table_bits)]; } static inline void wake_up_page(struct page *page, int bit) { __wake_up_bit(page_waitqueue(page), &page->flags, bit); } |
920c7a5d0 mm: remove fastca... |
535 |
void wait_on_page_bit(struct page *page, int bit_nr) |
1da177e4c Linux-2.6.12-rc2 |
536 537 538 539 |
{ DEFINE_WAIT_BIT(wait, &page->flags, bit_nr); if (test_bit(bit_nr, &page->flags)) |
7eaceacca block: remove per... |
540 |
__wait_on_bit(page_waitqueue(page), &wait, sleep_on_page, |
1da177e4c Linux-2.6.12-rc2 |
541 542 543 |
TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(wait_on_page_bit); |
f62e00cc3 mm: introduce wai... |
544 545 546 547 548 549 550 551 552 553 |
int wait_on_page_bit_killable(struct page *page, int bit_nr) { DEFINE_WAIT_BIT(wait, &page->flags, bit_nr); if (!test_bit(bit_nr, &page->flags)) return 0; return __wait_on_bit(page_waitqueue(page), &wait, sleep_on_page_killable, TASK_KILLABLE); } |
1da177e4c Linux-2.6.12-rc2 |
554 |
/** |
385e1ca5f CacheFiles: Permi... |
555 |
* add_page_wait_queue - Add an arbitrary waiter to a page's wait queue |
697f619fc filemap: fix kern... |
556 557 |
* @page: Page defining the wait queue of interest * @waiter: Waiter to add to the queue |
385e1ca5f CacheFiles: Permi... |
558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 |
* * Add an arbitrary @waiter to the wait queue for the nominated @page. */ void add_page_wait_queue(struct page *page, wait_queue_t *waiter) { wait_queue_head_t *q = page_waitqueue(page); unsigned long flags; spin_lock_irqsave(&q->lock, flags); __add_wait_queue(q, waiter); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL_GPL(add_page_wait_queue); /** |
485bb99b4 [PATCH] kernel-do... |
573 |
* unlock_page - unlock a locked page |
1da177e4c Linux-2.6.12-rc2 |
574 575 576 577 578 579 580 |
* @page: the page * * Unlocks the page and wakes up sleepers in ___wait_on_page_locked(). * Also wakes sleepers in wait_on_page_writeback() because the wakeup * mechananism between PageLocked pages and PageWriteback pages is shared. * But that's OK - sleepers in wait_on_page_writeback() just go back to sleep. * |
8413ac9d8 mm: page lock use... |
581 582 |
* The mb is necessary to enforce ordering between the clear_bit and the read * of the waitqueue (to avoid SMP races with a parallel wait_on_page_locked()). |
1da177e4c Linux-2.6.12-rc2 |
583 |
*/ |
920c7a5d0 mm: remove fastca... |
584 |
void unlock_page(struct page *page) |
1da177e4c Linux-2.6.12-rc2 |
585 |
{ |
8413ac9d8 mm: page lock use... |
586 587 588 |
VM_BUG_ON(!PageLocked(page)); clear_bit_unlock(PG_locked, &page->flags); smp_mb__after_clear_bit(); |
1da177e4c Linux-2.6.12-rc2 |
589 590 591 |
wake_up_page(page, PG_locked); } EXPORT_SYMBOL(unlock_page); |
485bb99b4 [PATCH] kernel-do... |
592 593 594 |
/** * end_page_writeback - end writeback against a page * @page: the page |
1da177e4c Linux-2.6.12-rc2 |
595 596 597 |
*/ void end_page_writeback(struct page *page) { |
ac6aadb24 mm: rotate_reclai... |
598 599 600 601 602 |
if (TestClearPageReclaim(page)) rotate_reclaimable_page(page); if (!test_clear_page_writeback(page)) BUG(); |
1da177e4c Linux-2.6.12-rc2 |
603 604 605 606 |
smp_mb__after_clear_bit(); wake_up_page(page, PG_writeback); } EXPORT_SYMBOL(end_page_writeback); |
485bb99b4 [PATCH] kernel-do... |
607 608 609 |
/** * __lock_page - get a lock on the page, assuming we need to sleep to get it * @page: the page to lock |
1da177e4c Linux-2.6.12-rc2 |
610 |
*/ |
920c7a5d0 mm: remove fastca... |
611 |
void __lock_page(struct page *page) |
1da177e4c Linux-2.6.12-rc2 |
612 613 |
{ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); |
7eaceacca block: remove per... |
614 |
__wait_on_bit_lock(page_waitqueue(page), &wait, sleep_on_page, |
1da177e4c Linux-2.6.12-rc2 |
615 616 617 |
TASK_UNINTERRUPTIBLE); } EXPORT_SYMBOL(__lock_page); |
b5606c2d4 remove final fast... |
618 |
int __lock_page_killable(struct page *page) |
2687a3569 Add lock_page_kil... |
619 620 621 622 |
{ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); return __wait_on_bit_lock(page_waitqueue(page), &wait, |
7eaceacca block: remove per... |
623 |
sleep_on_page_killable, TASK_KILLABLE); |
2687a3569 Add lock_page_kil... |
624 |
} |
18bc0bbd1 Staging: pohmelfs... |
625 |
EXPORT_SYMBOL_GPL(__lock_page_killable); |
2687a3569 Add lock_page_kil... |
626 |
|
d065bd810 mm: retry page fa... |
627 628 629 |
int __lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags) { |
37b23e052 x86,mm: make page... |
630 631 632 633 634 635 636 637 638 639 640 641 |
if (flags & FAULT_FLAG_ALLOW_RETRY) { /* * CAUTION! In this case, mmap_sem is not released * even though return 0. */ if (flags & FAULT_FLAG_RETRY_NOWAIT) return 0; up_read(&mm->mmap_sem); if (flags & FAULT_FLAG_KILLABLE) wait_on_page_locked_killable(page); else |
318b275fb mm: allow GUP to ... |
642 |
wait_on_page_locked(page); |
d065bd810 mm: retry page fa... |
643 |
return 0; |
37b23e052 x86,mm: make page... |
644 645 646 647 648 649 650 651 652 653 654 655 |
} else { if (flags & FAULT_FLAG_KILLABLE) { int ret; ret = __lock_page_killable(page); if (ret) { up_read(&mm->mmap_sem); return 0; } } else __lock_page(page); return 1; |
d065bd810 mm: retry page fa... |
656 657 |
} } |
485bb99b4 [PATCH] kernel-do... |
658 659 660 661 662 |
/** * find_get_page - find and get a page reference * @mapping: the address_space to search * @offset: the page index * |
da6052f7b [PATCH] update so... |
663 664 |
* Is there a pagecache struct page at the given (mapping, offset) tuple? * If yes, increment its refcount and return it; if no, return NULL. |
1da177e4c Linux-2.6.12-rc2 |
665 |
*/ |
a60637c85 mm: lockless page... |
666 |
struct page *find_get_page(struct address_space *mapping, pgoff_t offset) |
1da177e4c Linux-2.6.12-rc2 |
667 |
{ |
a60637c85 mm: lockless page... |
668 |
void **pagep; |
1da177e4c Linux-2.6.12-rc2 |
669 |
struct page *page; |
a60637c85 mm: lockless page... |
670 671 672 673 674 675 |
rcu_read_lock(); repeat: page = NULL; pagep = radix_tree_lookup_slot(&mapping->page_tree, offset); if (pagep) { page = radix_tree_deref_slot(pagep); |
27d20fddc radix-tree: fix R... |
676 677 |
if (unlikely(!page)) goto out; |
a2c16d6cb mm: let swap use ... |
678 |
if (radix_tree_exception(page)) { |
8079b1c85 mm: clarify the r... |
679 680 681 682 683 684 685 686 |
if (radix_tree_deref_retry(page)) goto repeat; /* * Otherwise, shmem/tmpfs must be storing a swap entry * here as an exceptional entry: so return it without * attempting to raise page count. */ goto out; |
a2c16d6cb mm: let swap use ... |
687 |
} |
a60637c85 mm: lockless page... |
688 689 690 691 692 693 694 695 696 697 698 699 700 |
if (!page_cache_get_speculative(page)) goto repeat; /* * 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); goto repeat; } } |
27d20fddc radix-tree: fix R... |
701 |
out: |
a60637c85 mm: lockless page... |
702 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
703 704 |
return page; } |
1da177e4c Linux-2.6.12-rc2 |
705 |
EXPORT_SYMBOL(find_get_page); |
485bb99b4 [PATCH] kernel-do... |
706 |
/** |
1da177e4c Linux-2.6.12-rc2 |
707 |
* find_lock_page - locate, pin and lock a pagecache page |
67be2dd1b [PATCH] DocBook: ... |
708 709 |
* @mapping: the address_space to search * @offset: the page index |
1da177e4c Linux-2.6.12-rc2 |
710 711 712 713 714 715 |
* * Locates the desired pagecache page, locks it, increments its reference * count and returns its address. * * Returns zero if the page was not present. find_lock_page() may sleep. */ |
a60637c85 mm: lockless page... |
716 |
struct page *find_lock_page(struct address_space *mapping, pgoff_t offset) |
1da177e4c Linux-2.6.12-rc2 |
717 718 |
{ struct page *page; |
1da177e4c Linux-2.6.12-rc2 |
719 |
repeat: |
a60637c85 mm: lockless page... |
720 |
page = find_get_page(mapping, offset); |
a2c16d6cb mm: let swap use ... |
721 |
if (page && !radix_tree_exception(page)) { |
a60637c85 mm: lockless page... |
722 723 724 725 726 727 |
lock_page(page); /* Has the page been truncated? */ if (unlikely(page->mapping != mapping)) { unlock_page(page); page_cache_release(page); goto repeat; |
1da177e4c Linux-2.6.12-rc2 |
728 |
} |
a60637c85 mm: lockless page... |
729 |
VM_BUG_ON(page->index != offset); |
1da177e4c Linux-2.6.12-rc2 |
730 |
} |
1da177e4c Linux-2.6.12-rc2 |
731 732 |
return page; } |
1da177e4c Linux-2.6.12-rc2 |
733 734 735 736 |
EXPORT_SYMBOL(find_lock_page); /** * find_or_create_page - locate or add a pagecache page |
67be2dd1b [PATCH] DocBook: ... |
737 738 739 |
* @mapping: the page's address_space * @index: the page's index into the mapping * @gfp_mask: page allocation mode |
1da177e4c Linux-2.6.12-rc2 |
740 741 742 743 744 745 746 747 748 749 750 751 752 |
* * Locates a page in the pagecache. If the page is not present, a new page * is allocated using @gfp_mask and is added to the pagecache and to the VM's * LRU list. The returned page is locked and has its reference count * incremented. * * find_or_create_page() may sleep, even if @gfp_flags specifies an atomic * allocation! * * find_or_create_page() returns the desired page's address, or zero on * memory exhaustion. */ struct page *find_or_create_page(struct address_space *mapping, |
57f6b96c0 filemap: convert ... |
753 |
pgoff_t index, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
754 |
{ |
eb2be1893 mm: buffered writ... |
755 |
struct page *page; |
1da177e4c Linux-2.6.12-rc2 |
756 757 758 759 |
int err; repeat: page = find_lock_page(mapping, index); if (!page) { |
eb2be1893 mm: buffered writ... |
760 761 762 |
page = __page_cache_alloc(gfp_mask); if (!page) return NULL; |
67d58ac47 mm: pagecache gfp... |
763 764 765 766 767 768 769 770 |
/* * We want a regular kernel memory (not highmem or DMA etc) * allocation for the radix tree nodes, but we need to honour * the context-specific requirements the caller has asked for. * GFP_RECLAIM_MASK collects those requirements. */ err = add_to_page_cache_lru(page, mapping, index, (gfp_mask & GFP_RECLAIM_MASK)); |
eb2be1893 mm: buffered writ... |
771 772 773 774 775 |
if (unlikely(err)) { page_cache_release(page); page = NULL; if (err == -EEXIST) goto repeat; |
1da177e4c Linux-2.6.12-rc2 |
776 |
} |
1da177e4c Linux-2.6.12-rc2 |
777 |
} |
1da177e4c Linux-2.6.12-rc2 |
778 779 |
return page; } |
1da177e4c Linux-2.6.12-rc2 |
780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 |
EXPORT_SYMBOL(find_or_create_page); /** * find_get_pages - gang pagecache lookup * @mapping: The address_space to search * @start: The starting page index * @nr_pages: The maximum number of pages * @pages: Where the resulting pages are placed * * find_get_pages() will search for and return a group of up to * @nr_pages pages in the mapping. The pages are placed at @pages. * find_get_pages() takes a reference against the returned pages. * * The search returns a group of mapping-contiguous pages with ascending * indexes. There may be holes in the indices due to not-present pages. * * find_get_pages() returns the number of pages which were found. */ unsigned find_get_pages(struct address_space *mapping, pgoff_t start, unsigned int nr_pages, struct page **pages) { unsigned int i; unsigned int ret; |
cc39c6a9b mm: account skipp... |
803 |
unsigned int nr_found, nr_skip; |
a60637c85 mm: lockless page... |
804 805 806 807 |
rcu_read_lock(); restart: nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree, |
6328650bb radix_tree: excep... |
808 |
(void ***)pages, NULL, start, nr_pages); |
a60637c85 mm: lockless page... |
809 |
ret = 0; |
cc39c6a9b mm: account skipp... |
810 |
nr_skip = 0; |
a60637c85 mm: lockless page... |
811 812 813 814 815 816 |
for (i = 0; i < nr_found; i++) { struct page *page; repeat: page = radix_tree_deref_slot((void **)pages[i]); if (unlikely(!page)) continue; |
9d8aa4ea8 mm: remove worryi... |
817 |
|
a2c16d6cb mm: let swap use ... |
818 |
if (radix_tree_exception(page)) { |
8079b1c85 mm: clarify the r... |
819 820 821 822 823 824 825 826 827 |
if (radix_tree_deref_retry(page)) { /* * Transient condition which can only trigger * when entry at index 0 moves out of or back * to root: none yet gotten, safe to restart. */ WARN_ON(start | i); goto restart; } |
a2c16d6cb mm: let swap use ... |
828 |
/* |
8079b1c85 mm: clarify the r... |
829 830 831 |
* Otherwise, shmem/tmpfs must be storing a swap entry * here as an exceptional entry: so skip over it - * we only reach this from invalidate_mapping_pages(). |
a2c16d6cb mm: let swap use ... |
832 |
*/ |
cc39c6a9b mm: account skipp... |
833 |
nr_skip++; |
8079b1c85 mm: clarify the r... |
834 |
continue; |
27d20fddc radix-tree: fix R... |
835 |
} |
a60637c85 mm: lockless page... |
836 837 838 839 840 841 842 843 844 |
if (!page_cache_get_speculative(page)) goto repeat; /* Has the page moved? */ if (unlikely(page != *((void **)pages[i]))) { page_cache_release(page); goto repeat; } |
1da177e4c Linux-2.6.12-rc2 |
845 |
|
a60637c85 mm: lockless page... |
846 847 848 |
pages[ret] = page; ret++; } |
5b280c0cc mm: don't return ... |
849 850 851 852 853 |
/* * If all entries were removed before we could secure them, * try again, because callers stop trying once 0 is returned. */ |
cc39c6a9b mm: account skipp... |
854 |
if (unlikely(!ret && nr_found > nr_skip)) |
5b280c0cc mm: don't return ... |
855 |
goto restart; |
a60637c85 mm: lockless page... |
856 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
857 858 |
return ret; } |
ebf43500e [PATCH] Add find_... |
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 |
/** * find_get_pages_contig - gang contiguous pagecache lookup * @mapping: The address_space to search * @index: The starting page index * @nr_pages: The maximum number of pages * @pages: Where the resulting pages are placed * * find_get_pages_contig() works exactly like find_get_pages(), except * that the returned number of pages are guaranteed to be contiguous. * * find_get_pages_contig() returns the number of pages which were found. */ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, unsigned int nr_pages, struct page **pages) { unsigned int i; unsigned int ret; |
a60637c85 mm: lockless page... |
876 877 878 879 880 |
unsigned int nr_found; rcu_read_lock(); restart: nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree, |
6328650bb radix_tree: excep... |
881 |
(void ***)pages, NULL, index, nr_pages); |
a60637c85 mm: lockless page... |
882 883 884 885 886 887 888 |
ret = 0; for (i = 0; i < nr_found; i++) { struct page *page; repeat: page = radix_tree_deref_slot((void **)pages[i]); if (unlikely(!page)) continue; |
9d8aa4ea8 mm: remove worryi... |
889 |
|
a2c16d6cb mm: let swap use ... |
890 |
if (radix_tree_exception(page)) { |
8079b1c85 mm: clarify the r... |
891 892 893 894 895 896 897 898 |
if (radix_tree_deref_retry(page)) { /* * Transient condition which can only trigger * when entry at index 0 moves out of or back * to root: none yet gotten, safe to restart. */ goto restart; } |
a2c16d6cb mm: let swap use ... |
899 |
/* |
8079b1c85 mm: clarify the r... |
900 901 902 |
* Otherwise, shmem/tmpfs must be storing a swap entry * here as an exceptional entry: so stop looking for * contiguous pages. |
a2c16d6cb mm: let swap use ... |
903 |
*/ |
8079b1c85 mm: clarify the r... |
904 |
break; |
a2c16d6cb mm: let swap use ... |
905 |
} |
ebf43500e [PATCH] Add find_... |
906 |
|
a60637c85 mm: lockless page... |
907 908 909 910 911 912 913 914 |
if (!page_cache_get_speculative(page)) goto repeat; /* Has the page moved? */ if (unlikely(page != *((void **)pages[i]))) { page_cache_release(page); goto repeat; } |
9cbb4cb21 mm: find_get_page... |
915 916 917 918 919 920 921 922 923 |
/* * must check mapping and index after taking the ref. * otherwise we can get both false positives and false * negatives, which is just confusing to the caller. */ if (page->mapping == NULL || page->index != index) { page_cache_release(page); break; } |
a60637c85 mm: lockless page... |
924 925 |
pages[ret] = page; ret++; |
ebf43500e [PATCH] Add find_... |
926 927 |
index++; } |
a60637c85 mm: lockless page... |
928 929 |
rcu_read_unlock(); return ret; |
ebf43500e [PATCH] Add find_... |
930 |
} |
ef71c15c4 AFS: export a cou... |
931 |
EXPORT_SYMBOL(find_get_pages_contig); |
ebf43500e [PATCH] Add find_... |
932 |
|
485bb99b4 [PATCH] kernel-do... |
933 934 935 936 937 938 939 940 |
/** * find_get_pages_tag - find and return pages that match @tag * @mapping: the address_space to search * @index: the starting page index * @tag: the tag index * @nr_pages: the maximum number of pages * @pages: where the resulting pages are placed * |
1da177e4c Linux-2.6.12-rc2 |
941 |
* Like find_get_pages, except we only return pages which are tagged with |
485bb99b4 [PATCH] kernel-do... |
942 |
* @tag. We update @index to index the next page for the traversal. |
1da177e4c Linux-2.6.12-rc2 |
943 944 945 946 947 948 |
*/ unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index, int tag, unsigned int nr_pages, struct page **pages) { unsigned int i; unsigned int ret; |
a60637c85 mm: lockless page... |
949 950 951 952 953 954 955 956 957 958 959 960 961 |
unsigned int nr_found; rcu_read_lock(); restart: nr_found = radix_tree_gang_lookup_tag_slot(&mapping->page_tree, (void ***)pages, *index, nr_pages, tag); ret = 0; for (i = 0; i < nr_found; i++) { struct page *page; repeat: page = radix_tree_deref_slot((void **)pages[i]); if (unlikely(!page)) continue; |
9d8aa4ea8 mm: remove worryi... |
962 |
|
a2c16d6cb mm: let swap use ... |
963 |
if (radix_tree_exception(page)) { |
8079b1c85 mm: clarify the r... |
964 965 966 967 968 969 970 971 |
if (radix_tree_deref_retry(page)) { /* * Transient condition which can only trigger * when entry at index 0 moves out of or back * to root: none yet gotten, safe to restart. */ goto restart; } |
a2c16d6cb mm: let swap use ... |
972 |
/* |
8079b1c85 mm: clarify the r... |
973 974 |
* This function is never used on a shmem/tmpfs * mapping, so a swap entry won't be found here. |
a2c16d6cb mm: let swap use ... |
975 |
*/ |
8079b1c85 mm: clarify the r... |
976 |
BUG(); |
a2c16d6cb mm: let swap use ... |
977 |
} |
a60637c85 mm: lockless page... |
978 979 980 981 982 983 984 985 986 987 988 989 990 |
if (!page_cache_get_speculative(page)) goto repeat; /* Has the page moved? */ if (unlikely(page != *((void **)pages[i]))) { page_cache_release(page); goto repeat; } pages[ret] = page; ret++; } |
5b280c0cc mm: don't return ... |
991 992 993 994 995 996 997 |
/* * If all entries were removed before we could secure them, * try again, because callers stop trying once 0 is returned. */ if (unlikely(!ret && nr_found)) goto restart; |
a60637c85 mm: lockless page... |
998 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
999 |
|
1da177e4c Linux-2.6.12-rc2 |
1000 1001 |
if (ret) *index = pages[ret - 1]->index + 1; |
a60637c85 mm: lockless page... |
1002 |
|
1da177e4c Linux-2.6.12-rc2 |
1003 1004 |
return ret; } |
ef71c15c4 AFS: export a cou... |
1005 |
EXPORT_SYMBOL(find_get_pages_tag); |
1da177e4c Linux-2.6.12-rc2 |
1006 |
|
485bb99b4 [PATCH] kernel-do... |
1007 1008 1009 1010 1011 |
/** * grab_cache_page_nowait - returns locked page at given index in given cache * @mapping: target address_space * @index: the page index * |
72fd4a35a [PATCH] Numerous ... |
1012 |
* Same as grab_cache_page(), but do not wait if the page is unavailable. |
1da177e4c Linux-2.6.12-rc2 |
1013 1014 1015 1016 1017 1018 1019 1020 |
* This is intended for speculative data generators, where the data can * be regenerated if the page couldn't be grabbed. This routine should * be safe to call while holding the lock for another page. * * Clear __GFP_FS when allocating the page to avoid recursion into the fs * and deadlock against the caller's locked page. */ struct page * |
57f6b96c0 filemap: convert ... |
1021 |
grab_cache_page_nowait(struct address_space *mapping, pgoff_t index) |
1da177e4c Linux-2.6.12-rc2 |
1022 1023 |
{ struct page *page = find_get_page(mapping, index); |
1da177e4c Linux-2.6.12-rc2 |
1024 1025 |
if (page) { |
529ae9aaa mm: rename page t... |
1026 |
if (trylock_page(page)) |
1da177e4c Linux-2.6.12-rc2 |
1027 1028 1029 1030 |
return page; page_cache_release(page); return NULL; } |
2ae88149a [PATCH] mm: clean... |
1031 |
page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS); |
67d58ac47 mm: pagecache gfp... |
1032 |
if (page && add_to_page_cache_lru(page, mapping, index, GFP_NOFS)) { |
1da177e4c Linux-2.6.12-rc2 |
1033 1034 1035 1036 1037 |
page_cache_release(page); page = NULL; } return page; } |
1da177e4c Linux-2.6.12-rc2 |
1038 |
EXPORT_SYMBOL(grab_cache_page_nowait); |
76d42bd96 [PATCH] readahead... |
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 |
/* * CD/DVDs are error prone. When a medium error occurs, the driver may fail * a _large_ part of the i/o request. Imagine the worst scenario: * * ---R__________________________________________B__________ * ^ reading here ^ bad block(assume 4k) * * read(R) => miss => readahead(R...B) => media error => frustrating retries * => failing the whole request => read(R) => read(R+1) => * readahead(R+1...B+1) => bang => read(R+2) => read(R+3) => * readahead(R+3...B+2) => bang => read(R+3) => read(R+4) => * readahead(R+4...B+3) => bang => read(R+4) => read(R+5) => ...... * * It is going insane. Fix it by quickly scaling down the readahead size. */ static void shrink_readahead_size_eio(struct file *filp, struct file_ra_state *ra) { |
76d42bd96 [PATCH] readahead... |
1057 |
ra->ra_pages /= 4; |
76d42bd96 [PATCH] readahead... |
1058 |
} |
485bb99b4 [PATCH] kernel-do... |
1059 |
/** |
36e789144 kill do_generic_m... |
1060 |
* do_generic_file_read - generic file read routine |
485bb99b4 [PATCH] kernel-do... |
1061 1062 1063 1064 1065 |
* @filp: the file to read * @ppos: current file position * @desc: read_descriptor * @actor: read method * |
1da177e4c Linux-2.6.12-rc2 |
1066 |
* This is a generic file read routine, and uses the |
485bb99b4 [PATCH] kernel-do... |
1067 |
* mapping->a_ops->readpage() function for the actual low-level stuff. |
1da177e4c Linux-2.6.12-rc2 |
1068 1069 1070 |
* * This is really ugly. But the goto's actually try to clarify some * of the logic when it comes to error handling etc. |
1da177e4c Linux-2.6.12-rc2 |
1071 |
*/ |
36e789144 kill do_generic_m... |
1072 1073 |
static void do_generic_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor) |
1da177e4c Linux-2.6.12-rc2 |
1074 |
{ |
36e789144 kill do_generic_m... |
1075 |
struct address_space *mapping = filp->f_mapping; |
1da177e4c Linux-2.6.12-rc2 |
1076 |
struct inode *inode = mapping->host; |
36e789144 kill do_generic_m... |
1077 |
struct file_ra_state *ra = &filp->f_ra; |
57f6b96c0 filemap: convert ... |
1078 1079 1080 1081 |
pgoff_t index; pgoff_t last_index; pgoff_t prev_index; unsigned long offset; /* offset into pagecache page */ |
ec0f16372 readahead: improv... |
1082 |
unsigned int prev_offset; |
1da177e4c Linux-2.6.12-rc2 |
1083 |
int error; |
1da177e4c Linux-2.6.12-rc2 |
1084 |
|
1da177e4c Linux-2.6.12-rc2 |
1085 |
index = *ppos >> PAGE_CACHE_SHIFT; |
7ff81078d readahead: remove... |
1086 1087 |
prev_index = ra->prev_pos >> PAGE_CACHE_SHIFT; prev_offset = ra->prev_pos & (PAGE_CACHE_SIZE-1); |
1da177e4c Linux-2.6.12-rc2 |
1088 1089 |
last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT; offset = *ppos & ~PAGE_CACHE_MASK; |
1da177e4c Linux-2.6.12-rc2 |
1090 1091 |
for (;;) { struct page *page; |
57f6b96c0 filemap: convert ... |
1092 |
pgoff_t end_index; |
a32ea1e1f Fix read/truncate... |
1093 |
loff_t isize; |
1da177e4c Linux-2.6.12-rc2 |
1094 |
unsigned long nr, ret; |
1da177e4c Linux-2.6.12-rc2 |
1095 |
cond_resched(); |
1da177e4c Linux-2.6.12-rc2 |
1096 1097 |
find_page: page = find_get_page(mapping, index); |
3ea89ee86 readahead: conver... |
1098 |
if (!page) { |
cf914a7d6 readahead: split ... |
1099 |
page_cache_sync_readahead(mapping, |
7ff81078d readahead: remove... |
1100 |
ra, filp, |
3ea89ee86 readahead: conver... |
1101 1102 1103 1104 1105 1106 |
index, last_index - index); page = find_get_page(mapping, index); if (unlikely(page == NULL)) goto no_cached_page; } if (PageReadahead(page)) { |
cf914a7d6 readahead: split ... |
1107 |
page_cache_async_readahead(mapping, |
7ff81078d readahead: remove... |
1108 |
ra, filp, page, |
3ea89ee86 readahead: conver... |
1109 |
index, last_index - index); |
1da177e4c Linux-2.6.12-rc2 |
1110 |
} |
8ab22b9ab vfs: pagecache us... |
1111 1112 1113 1114 |
if (!PageUptodate(page)) { if (inode->i_blkbits == PAGE_CACHE_SHIFT || !mapping->a_ops->is_partially_uptodate) goto page_not_up_to_date; |
529ae9aaa mm: rename page t... |
1115 |
if (!trylock_page(page)) |
8ab22b9ab vfs: pagecache us... |
1116 |
goto page_not_up_to_date; |
8d056cb96 mm/vfs: revalidat... |
1117 1118 1119 |
/* Did it get truncated before we got the lock? */ if (!page->mapping) goto page_not_up_to_date_locked; |
8ab22b9ab vfs: pagecache us... |
1120 1121 1122 1123 1124 |
if (!mapping->a_ops->is_partially_uptodate(page, desc, offset)) goto page_not_up_to_date_locked; unlock_page(page); } |
1da177e4c Linux-2.6.12-rc2 |
1125 |
page_ok: |
a32ea1e1f Fix read/truncate... |
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 |
/* * i_size must be checked after we know the page is Uptodate. * * Checking i_size after the check allows us to calculate * the correct value for "nr", which means the zero-filled * part of the page is not copied back to userspace (unless * another truncate extends the file - this is desired though). */ isize = i_size_read(inode); end_index = (isize - 1) >> PAGE_CACHE_SHIFT; if (unlikely(!isize || index > end_index)) { page_cache_release(page); goto out; } /* nr is the maximum number of bytes to copy from this page */ nr = PAGE_CACHE_SIZE; if (index == end_index) { nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; if (nr <= offset) { page_cache_release(page); goto out; } } nr = nr - offset; |
1da177e4c Linux-2.6.12-rc2 |
1152 1153 1154 1155 1156 1157 1158 1159 1160 |
/* If users can be writing to this page using arbitrary * virtual addresses, take care about potential aliasing * before reading the page on the kernel side. */ if (mapping_writably_mapped(mapping)) flush_dcache_page(page); /* |
ec0f16372 readahead: improv... |
1161 1162 |
* When a sequential read accesses a page several times, * only mark it as accessed the first time. |
1da177e4c Linux-2.6.12-rc2 |
1163 |
*/ |
ec0f16372 readahead: improv... |
1164 |
if (prev_index != index || offset != prev_offset) |
1da177e4c Linux-2.6.12-rc2 |
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 |
mark_page_accessed(page); prev_index = index; /* * Ok, we have the page, and it's up-to-date, so * now we can copy it to user space... * * The actor routine returns how many bytes were actually used.. * NOTE! This may not be the same as how much of a user buffer * we filled up (we may be padding etc), so we can only update * "pos" here (the actor routine has to update the user buffer * pointers and the remaining count). */ ret = actor(desc, page, offset, nr); offset += ret; index += offset >> PAGE_CACHE_SHIFT; offset &= ~PAGE_CACHE_MASK; |
6ce745ed3 readahead: code c... |
1182 |
prev_offset = offset; |
1da177e4c Linux-2.6.12-rc2 |
1183 1184 1185 1186 1187 1188 1189 1190 |
page_cache_release(page); if (ret == nr && desc->count) continue; goto out; page_not_up_to_date: /* Get exclusive access to the page ... */ |
854623235 do_generic_file_r... |
1191 1192 1193 |
error = lock_page_killable(page); if (unlikely(error)) goto readpage_error; |
1da177e4c Linux-2.6.12-rc2 |
1194 |
|
8ab22b9ab vfs: pagecache us... |
1195 |
page_not_up_to_date_locked: |
da6052f7b [PATCH] update so... |
1196 |
/* Did it get truncated before we got the lock? */ |
1da177e4c Linux-2.6.12-rc2 |
1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 |
if (!page->mapping) { unlock_page(page); page_cache_release(page); continue; } /* Did somebody else fill it already? */ if (PageUptodate(page)) { unlock_page(page); goto page_ok; } readpage: |
91803b499 do_generic_file_r... |
1210 1211 1212 1213 1214 1215 |
/* * A previous I/O error may have been due to temporary * failures, eg. multipath errors. * PG_error will be set again if readpage fails. */ ClearPageError(page); |
1da177e4c Linux-2.6.12-rc2 |
1216 1217 |
/* Start the actual read. The read will unlock the page. */ error = mapping->a_ops->readpage(filp, page); |
994fc28c7 [PATCH] add AOP_T... |
1218 1219 1220 1221 1222 |
if (unlikely(error)) { if (error == AOP_TRUNCATED_PAGE) { page_cache_release(page); goto find_page; } |
1da177e4c Linux-2.6.12-rc2 |
1223 |
goto readpage_error; |
994fc28c7 [PATCH] add AOP_T... |
1224 |
} |
1da177e4c Linux-2.6.12-rc2 |
1225 1226 |
if (!PageUptodate(page)) { |
854623235 do_generic_file_r... |
1227 1228 1229 |
error = lock_page_killable(page); if (unlikely(error)) goto readpage_error; |
1da177e4c Linux-2.6.12-rc2 |
1230 1231 1232 |
if (!PageUptodate(page)) { if (page->mapping == NULL) { /* |
2ecdc82ef kill unused inval... |
1233 |
* invalidate_mapping_pages got it |
1da177e4c Linux-2.6.12-rc2 |
1234 1235 1236 1237 1238 1239 |
*/ unlock_page(page); page_cache_release(page); goto find_page; } unlock_page(page); |
7ff81078d readahead: remove... |
1240 |
shrink_readahead_size_eio(filp, ra); |
854623235 do_generic_file_r... |
1241 1242 |
error = -EIO; goto readpage_error; |
1da177e4c Linux-2.6.12-rc2 |
1243 1244 1245 |
} unlock_page(page); } |
1da177e4c Linux-2.6.12-rc2 |
1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 |
goto page_ok; readpage_error: /* UHHUH! A synchronous read error occurred. Report it */ desc->error = error; page_cache_release(page); goto out; no_cached_page: /* * Ok, it wasn't cached, so we need to create a new * page.. */ |
eb2be1893 mm: buffered writ... |
1259 1260 1261 1262 |
page = page_cache_alloc_cold(mapping); if (!page) { desc->error = -ENOMEM; goto out; |
1da177e4c Linux-2.6.12-rc2 |
1263 |
} |
eb2be1893 mm: buffered writ... |
1264 |
error = add_to_page_cache_lru(page, mapping, |
1da177e4c Linux-2.6.12-rc2 |
1265 1266 |
index, GFP_KERNEL); if (error) { |
eb2be1893 mm: buffered writ... |
1267 |
page_cache_release(page); |
1da177e4c Linux-2.6.12-rc2 |
1268 1269 1270 1271 1272 |
if (error == -EEXIST) goto find_page; desc->error = error; goto out; } |
1da177e4c Linux-2.6.12-rc2 |
1273 1274 1275 1276 |
goto readpage; } out: |
7ff81078d readahead: remove... |
1277 1278 1279 |
ra->prev_pos = prev_index; ra->prev_pos <<= PAGE_CACHE_SHIFT; ra->prev_pos |= prev_offset; |
1da177e4c Linux-2.6.12-rc2 |
1280 |
|
f4e6b498d readahead: combin... |
1281 |
*ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset; |
0c6aa2639 mm: do_generic_fi... |
1282 |
file_accessed(filp); |
1da177e4c Linux-2.6.12-rc2 |
1283 |
} |
1da177e4c Linux-2.6.12-rc2 |
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 |
int file_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset, unsigned long size) { char *kaddr; unsigned long left, count = desc->count; if (size > count) size = count; /* * Faults on the destination of a read are common, so do it before * taking the kmap. */ if (!fault_in_pages_writeable(desc->arg.buf, size)) { kaddr = kmap_atomic(page, KM_USER0); left = __copy_to_user_inatomic(desc->arg.buf, kaddr + offset, size); kunmap_atomic(kaddr, KM_USER0); if (left == 0) goto success; } /* Do it the slow way */ kaddr = kmap(page); left = __copy_to_user(desc->arg.buf, kaddr + offset, size); kunmap(page); if (left) { size -= left; desc->error = -EFAULT; } success: desc->count = count - size; desc->written += size; desc->arg.buf += size; return size; } |
0ceb33143 mm: move common s... |
1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 |
/* * Performs necessary checks before doing a write * @iov: io vector request * @nr_segs: number of segments in the iovec * @count: number of bytes to write * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE * * Adjust number of segments and amount of bytes to write (nr_segs should be * properly initialized first). Returns appropriate error code that caller * should return or zero in case that write should be allowed. */ int generic_segment_checks(const struct iovec *iov, unsigned long *nr_segs, size_t *count, int access_flags) { unsigned long seg; size_t cnt = 0; for (seg = 0; seg < *nr_segs; seg++) { const struct iovec *iv = &iov[seg]; /* * If any segment has a negative length, or the cumulative * length ever wraps negative then return -EINVAL. */ cnt += iv->iov_len; if (unlikely((ssize_t)(cnt|iv->iov_len) < 0)) return -EINVAL; if (access_ok(access_flags, iv->iov_base, iv->iov_len)) continue; if (seg == 0) return -EFAULT; *nr_segs = seg; cnt -= iv->iov_len; /* This segment is no good */ break; } *count = cnt; return 0; } EXPORT_SYMBOL(generic_segment_checks); |
485bb99b4 [PATCH] kernel-do... |
1360 |
/** |
b2abacf3a [PATCH] mm: fix i... |
1361 |
* generic_file_aio_read - generic filesystem read routine |
485bb99b4 [PATCH] kernel-do... |
1362 1363 1364 |
* @iocb: kernel I/O control block * @iov: io vector request * @nr_segs: number of segments in the iovec |
b2abacf3a [PATCH] mm: fix i... |
1365 |
* @pos: current file position |
485bb99b4 [PATCH] kernel-do... |
1366 |
* |
1da177e4c Linux-2.6.12-rc2 |
1367 1368 1369 1370 |
* This is the "read()" routine for all filesystems * that can use the page cache directly. */ ssize_t |
543ade1fc [PATCH] Streamlin... |
1371 1372 |
generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos) |
1da177e4c Linux-2.6.12-rc2 |
1373 1374 1375 |
{ struct file *filp = iocb->ki_filp; ssize_t retval; |
66f998f61 fs: allow short d... |
1376 |
unsigned long seg = 0; |
1da177e4c Linux-2.6.12-rc2 |
1377 |
size_t count; |
543ade1fc [PATCH] Streamlin... |
1378 |
loff_t *ppos = &iocb->ki_pos; |
55602dd66 fs: make generic ... |
1379 |
struct blk_plug plug; |
1da177e4c Linux-2.6.12-rc2 |
1380 1381 |
count = 0; |
0ceb33143 mm: move common s... |
1382 1383 1384 |
retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); if (retval) return retval; |
1da177e4c Linux-2.6.12-rc2 |
1385 |
|
55602dd66 fs: make generic ... |
1386 |
blk_start_plug(&plug); |
1da177e4c Linux-2.6.12-rc2 |
1387 1388 |
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (filp->f_flags & O_DIRECT) { |
543ade1fc [PATCH] Streamlin... |
1389 |
loff_t size; |
1da177e4c Linux-2.6.12-rc2 |
1390 1391 1392 1393 1394 |
struct address_space *mapping; struct inode *inode; mapping = filp->f_mapping; inode = mapping->host; |
1da177e4c Linux-2.6.12-rc2 |
1395 1396 1397 1398 |
if (!count) goto out; /* skip atime */ size = i_size_read(inode); if (pos < size) { |
48b47c561 mm: direct IO sta... |
1399 1400 |
retval = filemap_write_and_wait_range(mapping, pos, pos + iov_length(iov, nr_segs) - 1); |
a969e903a kill generic_file... |
1401 1402 1403 1404 |
if (!retval) { retval = mapping->a_ops->direct_IO(READ, iocb, iov, pos, nr_segs); } |
66f998f61 fs: allow short d... |
1405 |
if (retval > 0) { |
1da177e4c Linux-2.6.12-rc2 |
1406 |
*ppos = pos + retval; |
66f998f61 fs: allow short d... |
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 |
count -= retval; } /* * Btrfs can have a short DIO read if we encounter * compressed extents, so if there was an error, or if * we've already read everything we wanted to, or if * there was a short read because we hit EOF, go ahead * and return. Otherwise fallthrough to buffered io for * the rest of the read. */ if (retval < 0 || !count || *ppos >= size) { |
11fa977ec generic_file_aio_... |
1419 1420 1421 |
file_accessed(filp); goto out; } |
0e0bcae3b [GFS2] Fix direct... |
1422 |
} |
1da177e4c Linux-2.6.12-rc2 |
1423 |
} |
66f998f61 fs: allow short d... |
1424 |
count = retval; |
11fa977ec generic_file_aio_... |
1425 1426 |
for (seg = 0; seg < nr_segs; seg++) { read_descriptor_t desc; |
66f998f61 fs: allow short d... |
1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 |
loff_t offset = 0; /* * If we did a short DIO read we need to skip the section of the * iov that we've already read data into. */ if (count) { if (count > iov[seg].iov_len) { count -= iov[seg].iov_len; continue; } offset = count; count = 0; } |
1da177e4c Linux-2.6.12-rc2 |
1441 |
|
11fa977ec generic_file_aio_... |
1442 |
desc.written = 0; |
66f998f61 fs: allow short d... |
1443 1444 |
desc.arg.buf = iov[seg].iov_base + offset; desc.count = iov[seg].iov_len - offset; |
11fa977ec generic_file_aio_... |
1445 1446 1447 1448 1449 1450 1451 1452 |
if (desc.count == 0) continue; desc.error = 0; do_generic_file_read(filp, ppos, &desc, file_read_actor); retval += desc.written; if (desc.error) { retval = retval ?: desc.error; break; |
1da177e4c Linux-2.6.12-rc2 |
1453 |
} |
11fa977ec generic_file_aio_... |
1454 1455 |
if (desc.count > 0) break; |
1da177e4c Linux-2.6.12-rc2 |
1456 1457 |
} out: |
55602dd66 fs: make generic ... |
1458 |
blk_finish_plug(&plug); |
1da177e4c Linux-2.6.12-rc2 |
1459 1460 |
return retval; } |
1da177e4c Linux-2.6.12-rc2 |
1461 |
EXPORT_SYMBOL(generic_file_aio_read); |
1da177e4c Linux-2.6.12-rc2 |
1462 1463 |
static ssize_t do_readahead(struct address_space *mapping, struct file *filp, |
57f6b96c0 filemap: convert ... |
1464 |
pgoff_t index, unsigned long nr) |
1da177e4c Linux-2.6.12-rc2 |
1465 1466 1467 |
{ if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage) return -EINVAL; |
f7e839dd3 readahead: move m... |
1468 |
force_page_cache_readahead(mapping, filp, index, nr); |
1da177e4c Linux-2.6.12-rc2 |
1469 1470 |
return 0; } |
6673e0c3f [CVE-2009-0029] S... |
1471 |
SYSCALL_DEFINE(readahead)(int fd, loff_t offset, size_t count) |
1da177e4c Linux-2.6.12-rc2 |
1472 1473 1474 1475 1476 1477 1478 1479 1480 |
{ ssize_t ret; struct file *file; ret = -EBADF; file = fget(fd); if (file) { if (file->f_mode & FMODE_READ) { struct address_space *mapping = file->f_mapping; |
57f6b96c0 filemap: convert ... |
1481 1482 |
pgoff_t start = offset >> PAGE_CACHE_SHIFT; pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT; |
1da177e4c Linux-2.6.12-rc2 |
1483 1484 1485 1486 1487 1488 1489 |
unsigned long len = end - start + 1; ret = do_readahead(mapping, file, start, len); } fput(file); } return ret; } |
6673e0c3f [CVE-2009-0029] S... |
1490 1491 1492 1493 1494 1495 1496 |
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS asmlinkage long SyS_readahead(long fd, loff_t offset, long count) { return SYSC_readahead((int) fd, offset, (size_t) count); } SYSCALL_ALIAS(sys_readahead, SyS_readahead); #endif |
1da177e4c Linux-2.6.12-rc2 |
1497 1498 |
#ifdef CONFIG_MMU |
485bb99b4 [PATCH] kernel-do... |
1499 1500 1501 1502 1503 |
/** * page_cache_read - adds requested page to the page cache if not already there * @file: file to read * @offset: page index * |
1da177e4c Linux-2.6.12-rc2 |
1504 1505 1506 |
* This adds the requested page to the page cache if it isn't already there, * and schedules an I/O to read in its contents from disk. */ |
920c7a5d0 mm: remove fastca... |
1507 |
static int page_cache_read(struct file *file, pgoff_t offset) |
1da177e4c Linux-2.6.12-rc2 |
1508 1509 1510 |
{ struct address_space *mapping = file->f_mapping; struct page *page; |
994fc28c7 [PATCH] add AOP_T... |
1511 |
int ret; |
1da177e4c Linux-2.6.12-rc2 |
1512 |
|
994fc28c7 [PATCH] add AOP_T... |
1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 |
do { page = page_cache_alloc_cold(mapping); if (!page) return -ENOMEM; ret = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL); if (ret == 0) ret = mapping->a_ops->readpage(file, page); else if (ret == -EEXIST) ret = 0; /* losing race to add is OK */ |
1da177e4c Linux-2.6.12-rc2 |
1523 |
|
1da177e4c Linux-2.6.12-rc2 |
1524 |
page_cache_release(page); |
1da177e4c Linux-2.6.12-rc2 |
1525 |
|
994fc28c7 [PATCH] add AOP_T... |
1526 1527 1528 |
} while (ret == AOP_TRUNCATED_PAGE); return ret; |
1da177e4c Linux-2.6.12-rc2 |
1529 1530 1531 |
} #define MMAP_LOTSAMISS (100) |
ef00e08e2 readahead: clean ... |
1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 |
/* * Synchronous readahead happens when we don't even find * a page in the page cache at all. */ static void do_sync_mmap_readahead(struct vm_area_struct *vma, struct file_ra_state *ra, struct file *file, pgoff_t offset) { unsigned long ra_pages; struct address_space *mapping = file->f_mapping; /* If we don't want any read-ahead, don't bother */ if (VM_RandomReadHint(vma)) return; |
275b12bf5 readahead: return... |
1547 1548 |
if (!ra->ra_pages) return; |
ef00e08e2 readahead: clean ... |
1549 |
|
2cbea1d3a readahead: trigge... |
1550 |
if (VM_SequentialReadHint(vma)) { |
7ffc59b4d readahead: enforc... |
1551 1552 |
page_cache_sync_readahead(mapping, ra, file, offset, ra->ra_pages); |
ef00e08e2 readahead: clean ... |
1553 1554 |
return; } |
207d04baa readahead: reduce... |
1555 1556 |
/* Avoid banging the cache line if not needed */ if (ra->mmap_miss < MMAP_LOTSAMISS * 10) |
ef00e08e2 readahead: clean ... |
1557 1558 1559 1560 1561 1562 1563 1564 |
ra->mmap_miss++; /* * Do we miss much more than hit in this file? If so, * stop bothering with read-ahead. It will only hurt. */ if (ra->mmap_miss > MMAP_LOTSAMISS) return; |
d30a11004 readahead: record... |
1565 1566 1567 |
/* * mmap read-around */ |
ef00e08e2 readahead: clean ... |
1568 |
ra_pages = max_sane_readahead(ra->ra_pages); |
275b12bf5 readahead: return... |
1569 1570 |
ra->start = max_t(long, 0, offset - ra_pages / 2); ra->size = ra_pages; |
2cbea1d3a readahead: trigge... |
1571 |
ra->async_size = ra_pages / 4; |
275b12bf5 readahead: return... |
1572 |
ra_submit(ra, mapping, file); |
ef00e08e2 readahead: clean ... |
1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 |
} /* * Asynchronous readahead happens when we find the page and PG_readahead, * so we want to possibly extend the readahead further.. */ static void do_async_mmap_readahead(struct vm_area_struct *vma, struct file_ra_state *ra, struct file *file, struct page *page, pgoff_t offset) { struct address_space *mapping = file->f_mapping; /* If we don't want any read-ahead, don't bother */ if (VM_RandomReadHint(vma)) return; if (ra->mmap_miss > 0) ra->mmap_miss--; if (PageReadahead(page)) |
2fad6f5de readahead: enforc... |
1593 1594 |
page_cache_async_readahead(mapping, ra, file, page, offset, ra->ra_pages); |
ef00e08e2 readahead: clean ... |
1595 |
} |
485bb99b4 [PATCH] kernel-do... |
1596 |
/** |
54cb8821d mm: merge populat... |
1597 |
* filemap_fault - read in file data for page fault handling |
d0217ac04 mm: fault feedbac... |
1598 1599 |
* @vma: vma in which the fault was taken * @vmf: struct vm_fault containing details of the fault |
485bb99b4 [PATCH] kernel-do... |
1600 |
* |
54cb8821d mm: merge populat... |
1601 |
* filemap_fault() is invoked via the vma operations vector for a |
1da177e4c Linux-2.6.12-rc2 |
1602 1603 1604 1605 1606 1607 |
* mapped memory region to read in file data during a page fault. * * The goto's are kind of ugly, but this streamlines the normal case of having * it in the page cache, and handles the special cases reasonably without * having a lot of duplicated code. */ |
d0217ac04 mm: fault feedbac... |
1608 |
int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4c Linux-2.6.12-rc2 |
1609 1610 |
{ int error; |
54cb8821d mm: merge populat... |
1611 |
struct file *file = vma->vm_file; |
1da177e4c Linux-2.6.12-rc2 |
1612 1613 1614 |
struct address_space *mapping = file->f_mapping; struct file_ra_state *ra = &file->f_ra; struct inode *inode = mapping->host; |
ef00e08e2 readahead: clean ... |
1615 |
pgoff_t offset = vmf->pgoff; |
1da177e4c Linux-2.6.12-rc2 |
1616 |
struct page *page; |
2004dc8ee Use pgoff_t inste... |
1617 |
pgoff_t size; |
83c54070e mm: fault feedbac... |
1618 |
int ret = 0; |
1da177e4c Linux-2.6.12-rc2 |
1619 |
|
1da177e4c Linux-2.6.12-rc2 |
1620 |
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
ef00e08e2 readahead: clean ... |
1621 |
if (offset >= size) |
5307cc1aa Remove broken ptr... |
1622 |
return VM_FAULT_SIGBUS; |
1da177e4c Linux-2.6.12-rc2 |
1623 |
|
1da177e4c Linux-2.6.12-rc2 |
1624 |
/* |
1da177e4c Linux-2.6.12-rc2 |
1625 1626 |
* Do we have something in the page cache already? */ |
ef00e08e2 readahead: clean ... |
1627 1628 |
page = find_get_page(mapping, offset); if (likely(page)) { |
1da177e4c Linux-2.6.12-rc2 |
1629 |
/* |
ef00e08e2 readahead: clean ... |
1630 1631 |
* We found the page, so try async readahead before * waiting for the lock. |
1da177e4c Linux-2.6.12-rc2 |
1632 |
*/ |
ef00e08e2 readahead: clean ... |
1633 |
do_async_mmap_readahead(vma, ra, file, page, offset); |
ef00e08e2 readahead: clean ... |
1634 1635 1636 1637 |
} else { /* No page in the page cache at all */ do_sync_mmap_readahead(vma, ra, file, offset); count_vm_event(PGMAJFAULT); |
456f998ec memcg: add the pa... |
1638 |
mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); |
ef00e08e2 readahead: clean ... |
1639 1640 |
ret = VM_FAULT_MAJOR; retry_find: |
b522c94da mm: filemap_fault... |
1641 |
page = find_get_page(mapping, offset); |
1da177e4c Linux-2.6.12-rc2 |
1642 1643 1644 |
if (!page) goto no_cached_page; } |
d88c0922f Release page refe... |
1645 1646 |
if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags)) { page_cache_release(page); |
d065bd810 mm: retry page fa... |
1647 |
return ret | VM_FAULT_RETRY; |
d88c0922f Release page refe... |
1648 |
} |
b522c94da mm: filemap_fault... |
1649 1650 1651 1652 1653 1654 1655 1656 |
/* Did it get truncated? */ if (unlikely(page->mapping != mapping)) { unlock_page(page); put_page(page); goto retry_find; } VM_BUG_ON(page->index != offset); |
1da177e4c Linux-2.6.12-rc2 |
1657 |
/* |
d00806b18 mm: fix fault vs ... |
1658 1659 |
* We have a locked page in the page cache, now we need to check * that it's up-to-date. If not, it is going to be due to an error. |
1da177e4c Linux-2.6.12-rc2 |
1660 |
*/ |
d00806b18 mm: fix fault vs ... |
1661 |
if (unlikely(!PageUptodate(page))) |
1da177e4c Linux-2.6.12-rc2 |
1662 |
goto page_not_uptodate; |
ef00e08e2 readahead: clean ... |
1663 1664 1665 1666 |
/* * Found the page and have a reference on it. * We must recheck i_size under page lock. */ |
d00806b18 mm: fix fault vs ... |
1667 |
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
ef00e08e2 readahead: clean ... |
1668 |
if (unlikely(offset >= size)) { |
d00806b18 mm: fix fault vs ... |
1669 |
unlock_page(page); |
745ad48e8 fix page release ... |
1670 |
page_cache_release(page); |
5307cc1aa Remove broken ptr... |
1671 |
return VM_FAULT_SIGBUS; |
d00806b18 mm: fix fault vs ... |
1672 |
} |
d0217ac04 mm: fault feedbac... |
1673 |
vmf->page = page; |
83c54070e mm: fault feedbac... |
1674 |
return ret | VM_FAULT_LOCKED; |
1da177e4c Linux-2.6.12-rc2 |
1675 |
|
1da177e4c Linux-2.6.12-rc2 |
1676 1677 1678 1679 1680 |
no_cached_page: /* * We're only likely to ever get here if MADV_RANDOM is in * effect. */ |
ef00e08e2 readahead: clean ... |
1681 |
error = page_cache_read(file, offset); |
1da177e4c Linux-2.6.12-rc2 |
1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 |
/* * The page we want has now been added to the page cache. * In the unlikely event that someone removed it in the * meantime, we'll just come back here and read it again. */ if (error >= 0) goto retry_find; /* * An error return from page_cache_read can result if the * system is low on memory, or a problem occurs while trying * to schedule I/O. */ if (error == -ENOMEM) |
d0217ac04 mm: fault feedbac... |
1697 1698 |
return VM_FAULT_OOM; return VM_FAULT_SIGBUS; |
1da177e4c Linux-2.6.12-rc2 |
1699 1700 |
page_not_uptodate: |
1da177e4c Linux-2.6.12-rc2 |
1701 1702 1703 1704 1705 1706 |
/* * Umm, take care of errors if the page isn't up-to-date. * Try to re-read it _once_. We do this synchronously, * because there really aren't any performance issues here * and we need to check for errors. */ |
1da177e4c Linux-2.6.12-rc2 |
1707 |
ClearPageError(page); |
994fc28c7 [PATCH] add AOP_T... |
1708 |
error = mapping->a_ops->readpage(file, page); |
3ef0f720e mm: fix infinite ... |
1709 1710 1711 1712 1713 |
if (!error) { wait_on_page_locked(page); if (!PageUptodate(page)) error = -EIO; } |
d00806b18 mm: fix fault vs ... |
1714 1715 1716 |
page_cache_release(page); if (!error || error == AOP_TRUNCATED_PAGE) |
994fc28c7 [PATCH] add AOP_T... |
1717 |
goto retry_find; |
1da177e4c Linux-2.6.12-rc2 |
1718 |
|
d00806b18 mm: fix fault vs ... |
1719 |
/* Things didn't work out. Return zero to tell the mm layer so. */ |
76d42bd96 [PATCH] readahead... |
1720 |
shrink_readahead_size_eio(file, ra); |
d0217ac04 mm: fault feedbac... |
1721 |
return VM_FAULT_SIGBUS; |
54cb8821d mm: merge populat... |
1722 1723 |
} EXPORT_SYMBOL(filemap_fault); |
f0f37e2f7 const: mark struc... |
1724 |
const struct vm_operations_struct generic_file_vm_ops = { |
54cb8821d mm: merge populat... |
1725 |
.fault = filemap_fault, |
1da177e4c Linux-2.6.12-rc2 |
1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 |
}; /* This is used for a general mmap of a disk file */ int generic_file_mmap(struct file * file, struct vm_area_struct * vma) { struct address_space *mapping = file->f_mapping; if (!mapping->a_ops->readpage) return -ENOEXEC; file_accessed(file); vma->vm_ops = &generic_file_vm_ops; |
d0217ac04 mm: fault feedbac... |
1738 |
vma->vm_flags |= VM_CAN_NONLINEAR; |
1da177e4c Linux-2.6.12-rc2 |
1739 1740 |
return 0; } |
1da177e4c Linux-2.6.12-rc2 |
1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 |
/* * This is for filesystems which do not implement ->writepage. */ int generic_file_readonly_mmap(struct file *file, struct vm_area_struct *vma) { if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) return -EINVAL; return generic_file_mmap(file, vma); } #else int generic_file_mmap(struct file * file, struct vm_area_struct * vma) { return -ENOSYS; } int generic_file_readonly_mmap(struct file * file, struct vm_area_struct * vma) { return -ENOSYS; } #endif /* CONFIG_MMU */ EXPORT_SYMBOL(generic_file_mmap); EXPORT_SYMBOL(generic_file_readonly_mmap); |
6fe6900e1 mm: make read_cac... |
1764 |
static struct page *__read_cache_page(struct address_space *mapping, |
57f6b96c0 filemap: convert ... |
1765 |
pgoff_t index, |
5e5358e7c mm: cleanup descr... |
1766 |
int (*filler)(void *, struct page *), |
0531b2aac mm: add new 'read... |
1767 1768 |
void *data, gfp_t gfp) |
1da177e4c Linux-2.6.12-rc2 |
1769 |
{ |
eb2be1893 mm: buffered writ... |
1770 |
struct page *page; |
1da177e4c Linux-2.6.12-rc2 |
1771 1772 1773 1774 |
int err; repeat: page = find_get_page(mapping, index); if (!page) { |
0531b2aac mm: add new 'read... |
1775 |
page = __page_cache_alloc(gfp | __GFP_COLD); |
eb2be1893 mm: buffered writ... |
1776 1777 1778 1779 1780 1781 1782 |
if (!page) return ERR_PTR(-ENOMEM); err = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL); if (unlikely(err)) { page_cache_release(page); if (err == -EEXIST) goto repeat; |
1da177e4c Linux-2.6.12-rc2 |
1783 |
/* Presumably ENOMEM for radix tree node */ |
1da177e4c Linux-2.6.12-rc2 |
1784 1785 |
return ERR_PTR(err); } |
1da177e4c Linux-2.6.12-rc2 |
1786 1787 1788 1789 1790 1791 |
err = filler(data, page); if (err < 0) { page_cache_release(page); page = ERR_PTR(err); } } |
1da177e4c Linux-2.6.12-rc2 |
1792 1793 |
return page; } |
0531b2aac mm: add new 'read... |
1794 |
static struct page *do_read_cache_page(struct address_space *mapping, |
57f6b96c0 filemap: convert ... |
1795 |
pgoff_t index, |
5e5358e7c mm: cleanup descr... |
1796 |
int (*filler)(void *, struct page *), |
0531b2aac mm: add new 'read... |
1797 1798 |
void *data, gfp_t gfp) |
1da177e4c Linux-2.6.12-rc2 |
1799 1800 1801 1802 1803 |
{ struct page *page; int err; retry: |
0531b2aac mm: add new 'read... |
1804 |
page = __read_cache_page(mapping, index, filler, data, gfp); |
1da177e4c Linux-2.6.12-rc2 |
1805 |
if (IS_ERR(page)) |
c855ff371 Fix a bad error c... |
1806 |
return page; |
1da177e4c Linux-2.6.12-rc2 |
1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 |
if (PageUptodate(page)) goto out; lock_page(page); if (!page->mapping) { unlock_page(page); page_cache_release(page); goto retry; } if (PageUptodate(page)) { unlock_page(page); goto out; } err = filler(data, page); if (err < 0) { page_cache_release(page); |
c855ff371 Fix a bad error c... |
1823 |
return ERR_PTR(err); |
1da177e4c Linux-2.6.12-rc2 |
1824 |
} |
c855ff371 Fix a bad error c... |
1825 |
out: |
6fe6900e1 mm: make read_cac... |
1826 1827 1828 |
mark_page_accessed(page); return page; } |
0531b2aac mm: add new 'read... |
1829 1830 1831 1832 1833 1834 |
/** * read_cache_page_async - read into page cache, fill it if needed * @mapping: the page's address_space * @index: the page index * @filler: function to perform the read |
5e5358e7c mm: cleanup descr... |
1835 |
* @data: first arg to filler(data, page) function, often left as NULL |
0531b2aac mm: add new 'read... |
1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 |
* * Same as read_cache_page, but don't wait for page to become unlocked * after submitting it to the filler. * * Read into the page cache. If a page already exists, and PageUptodate() is * not set, try to fill the page but don't wait for it to become unlocked. * * If the page does not get brought uptodate, return -EIO. */ struct page *read_cache_page_async(struct address_space *mapping, pgoff_t index, |
5e5358e7c mm: cleanup descr... |
1847 |
int (*filler)(void *, struct page *), |
0531b2aac mm: add new 'read... |
1848 1849 1850 1851 |
void *data) { return do_read_cache_page(mapping, index, filler, data, mapping_gfp_mask(mapping)); } |
6fe6900e1 mm: make read_cac... |
1852 |
EXPORT_SYMBOL(read_cache_page_async); |
0531b2aac mm: add new 'read... |
1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 |
static struct page *wait_on_page_read(struct page *page) { if (!IS_ERR(page)) { wait_on_page_locked(page); if (!PageUptodate(page)) { page_cache_release(page); page = ERR_PTR(-EIO); } } return page; } /** * read_cache_page_gfp - read into page cache, using specified page allocation flags. * @mapping: the page's address_space * @index: the page index * @gfp: the page allocator flags to use if allocating * * This is the same as "read_mapping_page(mapping, index, NULL)", but with * any new page allocations done using the specified allocation flags. Note * that the Radix tree operations will still use GFP_KERNEL, so you can't * expect to do this atomically or anything like that - but you can pass in * other page requirements. * * If the page does not get brought uptodate, return -EIO. */ struct page *read_cache_page_gfp(struct address_space *mapping, pgoff_t index, gfp_t gfp) { filler_t *filler = (filler_t *)mapping->a_ops->readpage; return wait_on_page_read(do_read_cache_page(mapping, index, filler, NULL, gfp)); } EXPORT_SYMBOL(read_cache_page_gfp); |
6fe6900e1 mm: make read_cac... |
1888 1889 1890 1891 1892 |
/** * read_cache_page - read into page cache, fill it if needed * @mapping: the page's address_space * @index: the page index * @filler: function to perform the read |
5e5358e7c mm: cleanup descr... |
1893 |
* @data: first arg to filler(data, page) function, often left as NULL |
6fe6900e1 mm: make read_cac... |
1894 1895 1896 1897 1898 1899 1900 |
* * Read into the page cache. If a page already exists, and PageUptodate() is * not set, try to fill the page then wait for it to become unlocked. * * If the page does not get brought uptodate, return -EIO. */ struct page *read_cache_page(struct address_space *mapping, |
57f6b96c0 filemap: convert ... |
1901 |
pgoff_t index, |
5e5358e7c mm: cleanup descr... |
1902 |
int (*filler)(void *, struct page *), |
6fe6900e1 mm: make read_cac... |
1903 1904 |
void *data) { |
0531b2aac mm: add new 'read... |
1905 |
return wait_on_page_read(read_cache_page_async(mapping, index, filler, data)); |
1da177e4c Linux-2.6.12-rc2 |
1906 |
} |
1da177e4c Linux-2.6.12-rc2 |
1907 1908 1909 |
EXPORT_SYMBOL(read_cache_page); /* |
1da177e4c Linux-2.6.12-rc2 |
1910 1911 1912 1913 1914 |
* The logic we want is * * if suid or (sgid and xgrp) * remove privs */ |
01de85e05 [PATCH] Add lockl... |
1915 |
int should_remove_suid(struct dentry *dentry) |
1da177e4c Linux-2.6.12-rc2 |
1916 1917 1918 |
{ mode_t mode = dentry->d_inode->i_mode; int kill = 0; |
1da177e4c Linux-2.6.12-rc2 |
1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 |
/* suid always must be killed */ if (unlikely(mode & S_ISUID)) kill = ATTR_KILL_SUID; /* * sgid without any exec bits is just a mandatory locking mark; leave * it alone. If some exec bits are set, it's a real sgid; kill it. */ if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) kill |= ATTR_KILL_SGID; |
7f5ff766a kill suid bit onl... |
1930 |
if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode))) |
01de85e05 [PATCH] Add lockl... |
1931 |
return kill; |
1da177e4c Linux-2.6.12-rc2 |
1932 |
|
01de85e05 [PATCH] Add lockl... |
1933 1934 |
return 0; } |
d23a147bb [PATCH] Export sh... |
1935 |
EXPORT_SYMBOL(should_remove_suid); |
01de85e05 [PATCH] Add lockl... |
1936 |
|
7f3d4ee10 vfs: splice remov... |
1937 |
static int __remove_suid(struct dentry *dentry, int kill) |
01de85e05 [PATCH] Add lockl... |
1938 1939 1940 1941 1942 1943 |
{ struct iattr newattrs; newattrs.ia_valid = ATTR_FORCE | kill; return notify_change(dentry, &newattrs); } |
2f1936b87 [patch 3/5] vfs: ... |
1944 |
int file_remove_suid(struct file *file) |
01de85e05 [PATCH] Add lockl... |
1945 |
{ |
2f1936b87 [patch 3/5] vfs: ... |
1946 |
struct dentry *dentry = file->f_path.dentry; |
69b457329 Cache xattr secur... |
1947 1948 1949 |
struct inode *inode = dentry->d_inode; int killsuid; int killpriv; |
b53767719 Implement file po... |
1950 |
int error = 0; |
01de85e05 [PATCH] Add lockl... |
1951 |
|
69b457329 Cache xattr secur... |
1952 1953 1954 1955 1956 1957 |
/* Fast path for nothing security related */ if (IS_NOSEC(inode)) return 0; killsuid = should_remove_suid(dentry); killpriv = security_inode_need_killpriv(dentry); |
b53767719 Implement file po... |
1958 1959 1960 1961 1962 1963 |
if (killpriv < 0) return killpriv; if (killpriv) error = security_inode_killpriv(dentry); if (!error && killsuid) error = __remove_suid(dentry, killsuid); |
9e1f1de02 more conservative... |
1964 |
if (!error && (inode->i_sb->s_flags & MS_NOSEC)) |
69b457329 Cache xattr secur... |
1965 |
inode->i_flags |= S_NOSEC; |
01de85e05 [PATCH] Add lockl... |
1966 |
|
b53767719 Implement file po... |
1967 |
return error; |
1da177e4c Linux-2.6.12-rc2 |
1968 |
} |
2f1936b87 [patch 3/5] vfs: ... |
1969 |
EXPORT_SYMBOL(file_remove_suid); |
1da177e4c Linux-2.6.12-rc2 |
1970 |
|
2f718ffc1 mm: buffered writ... |
1971 |
static size_t __iovec_copy_from_user_inatomic(char *vaddr, |
1da177e4c Linux-2.6.12-rc2 |
1972 1973 |
const struct iovec *iov, size_t base, size_t bytes) { |
f18005369 x86, mm: dont use... |
1974 |
size_t copied = 0, left = 0; |
1da177e4c Linux-2.6.12-rc2 |
1975 1976 1977 1978 1979 1980 |
while (bytes) { char __user *buf = iov->iov_base + base; int copy = min(bytes, iov->iov_len - base); base = 0; |
f18005369 x86, mm: dont use... |
1981 |
left = __copy_from_user_inatomic(vaddr, buf, copy); |
1da177e4c Linux-2.6.12-rc2 |
1982 1983 1984 1985 |
copied += copy; bytes -= copy; vaddr += copy; iov++; |
01408c493 [PATCH] Prepare f... |
1986 |
if (unlikely(left)) |
1da177e4c Linux-2.6.12-rc2 |
1987 |
break; |
1da177e4c Linux-2.6.12-rc2 |
1988 1989 1990 1991 1992 |
} return copied - left; } /* |
2f718ffc1 mm: buffered writ... |
1993 |
* Copy as much as we can into the page and return the number of bytes which |
af901ca18 tree-wide: fix as... |
1994 |
* were successfully copied. If a fault is encountered then return the number of |
2f718ffc1 mm: buffered writ... |
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 |
* bytes which were copied. */ size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes) { char *kaddr; size_t copied; BUG_ON(!in_atomic()); kaddr = kmap_atomic(page, KM_USER0); if (likely(i->nr_segs == 1)) { int left; char __user *buf = i->iov->iov_base + i->iov_offset; |
f18005369 x86, mm: dont use... |
2008 |
left = __copy_from_user_inatomic(kaddr + offset, buf, bytes); |
2f718ffc1 mm: buffered writ... |
2009 2010 2011 2012 2013 2014 2015 2016 2017 |
copied = bytes - left; } else { copied = __iovec_copy_from_user_inatomic(kaddr + offset, i->iov, i->iov_offset, bytes); } kunmap_atomic(kaddr, KM_USER0); return copied; } |
89e107877 fs: new cont helpers |
2018 |
EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); |
2f718ffc1 mm: buffered writ... |
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 |
/* * This has the same sideeffects and return value as * iov_iter_copy_from_user_atomic(). * The difference is that it attempts to resolve faults. * Page must not be locked. */ size_t iov_iter_copy_from_user(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes) { char *kaddr; size_t copied; kaddr = kmap(page); if (likely(i->nr_segs == 1)) { int left; char __user *buf = i->iov->iov_base + i->iov_offset; |
f18005369 x86, mm: dont use... |
2036 |
left = __copy_from_user(kaddr + offset, buf, bytes); |
2f718ffc1 mm: buffered writ... |
2037 2038 2039 2040 2041 2042 2043 2044 |
copied = bytes - left; } else { copied = __iovec_copy_from_user_inatomic(kaddr + offset, i->iov, i->iov_offset, bytes); } kunmap(page); return copied; } |
89e107877 fs: new cont helpers |
2045 |
EXPORT_SYMBOL(iov_iter_copy_from_user); |
2f718ffc1 mm: buffered writ... |
2046 |
|
f7009264c iov_iter_advance(... |
2047 |
void iov_iter_advance(struct iov_iter *i, size_t bytes) |
2f718ffc1 mm: buffered writ... |
2048 |
{ |
f7009264c iov_iter_advance(... |
2049 |
BUG_ON(i->count < bytes); |
2f718ffc1 mm: buffered writ... |
2050 2051 |
if (likely(i->nr_segs == 1)) { i->iov_offset += bytes; |
f7009264c iov_iter_advance(... |
2052 |
i->count -= bytes; |
2f718ffc1 mm: buffered writ... |
2053 2054 2055 |
} else { const struct iovec *iov = i->iov; size_t base = i->iov_offset; |
39be79c16 vfs: iov_iter: ha... |
2056 |
unsigned long nr_segs = i->nr_segs; |
2f718ffc1 mm: buffered writ... |
2057 |
|
124d3b704 fix writev regres... |
2058 2059 |
/* * The !iov->iov_len check ensures we skip over unlikely |
f7009264c iov_iter_advance(... |
2060 |
* zero-length segments (without overruning the iovec). |
124d3b704 fix writev regres... |
2061 |
*/ |
94ad374a0 Fix off-by-one er... |
2062 |
while (bytes || unlikely(i->count && !iov->iov_len)) { |
f7009264c iov_iter_advance(... |
2063 |
int copy; |
2f718ffc1 mm: buffered writ... |
2064 |
|
f7009264c iov_iter_advance(... |
2065 2066 2067 |
copy = min(bytes, iov->iov_len - base); BUG_ON(!i->count || i->count < copy); i->count -= copy; |
2f718ffc1 mm: buffered writ... |
2068 2069 2070 2071 |
bytes -= copy; base += copy; if (iov->iov_len == base) { iov++; |
39be79c16 vfs: iov_iter: ha... |
2072 |
nr_segs--; |
2f718ffc1 mm: buffered writ... |
2073 2074 2075 2076 2077 |
base = 0; } } i->iov = iov; i->iov_offset = base; |
39be79c16 vfs: iov_iter: ha... |
2078 |
i->nr_segs = nr_segs; |
2f718ffc1 mm: buffered writ... |
2079 2080 |
} } |
89e107877 fs: new cont helpers |
2081 |
EXPORT_SYMBOL(iov_iter_advance); |
2f718ffc1 mm: buffered writ... |
2082 |
|
afddba49d fs: introduce wri... |
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 |
/* * Fault in the first iovec of the given iov_iter, to a maximum length * of bytes. Returns 0 on success, or non-zero if the memory could not be * accessed (ie. because it is an invalid address). * * writev-intensive code may want this to prefault several iovecs -- that * would be possible (callers must not rely on the fact that _only_ the * first iovec will be faulted with the current implementation). */ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) |
2f718ffc1 mm: buffered writ... |
2093 |
{ |
2f718ffc1 mm: buffered writ... |
2094 |
char __user *buf = i->iov->iov_base + i->iov_offset; |
afddba49d fs: introduce wri... |
2095 2096 |
bytes = min(bytes, i->iov->iov_len - i->iov_offset); return fault_in_pages_readable(buf, bytes); |
2f718ffc1 mm: buffered writ... |
2097 |
} |
89e107877 fs: new cont helpers |
2098 |
EXPORT_SYMBOL(iov_iter_fault_in_readable); |
2f718ffc1 mm: buffered writ... |
2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 |
/* * Return the count of just the current iov_iter segment. */ size_t iov_iter_single_seg_count(struct iov_iter *i) { const struct iovec *iov = i->iov; if (i->nr_segs == 1) return i->count; else return min(i->count, iov->iov_len - i->iov_offset); } |
89e107877 fs: new cont helpers |
2111 |
EXPORT_SYMBOL(iov_iter_single_seg_count); |
2f718ffc1 mm: buffered writ... |
2112 2113 |
/* |
1da177e4c Linux-2.6.12-rc2 |
2114 2115 |
* Performs necessary checks before doing a write * |
485bb99b4 [PATCH] kernel-do... |
2116 |
* Can adjust writing position or amount of bytes to write. |
1da177e4c Linux-2.6.12-rc2 |
2117 2118 2119 2120 2121 2122 |
* Returns appropriate error code that caller should return or * zero in case that write should be allowed. */ inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk) { struct inode *inode = file->f_mapping->host; |
59e99e5b9 mm: use rlimit he... |
2123 |
unsigned long limit = rlimit(RLIMIT_FSIZE); |
1da177e4c Linux-2.6.12-rc2 |
2124 2125 2126 |
if (unlikely(*pos < 0)) return -EINVAL; |
1da177e4c Linux-2.6.12-rc2 |
2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 |
if (!isblk) { /* FIXME: this is for backwards compatibility with 2.4 */ if (file->f_flags & O_APPEND) *pos = i_size_read(inode); if (limit != RLIM_INFINITY) { if (*pos >= limit) { send_sig(SIGXFSZ, current, 0); return -EFBIG; } if (*count > limit - (typeof(limit))*pos) { *count = limit - (typeof(limit))*pos; } } } /* * LFS rule */ if (unlikely(*pos + *count > MAX_NON_LFS && !(file->f_flags & O_LARGEFILE))) { if (*pos >= MAX_NON_LFS) { |
1da177e4c Linux-2.6.12-rc2 |
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 |
return -EFBIG; } if (*count > MAX_NON_LFS - (unsigned long)*pos) { *count = MAX_NON_LFS - (unsigned long)*pos; } } /* * Are we about to exceed the fs block limit ? * * If we have written data it becomes a short write. If we have * exceeded without writing data we send a signal and return EFBIG. * Linus frestrict idea will clean these up nicely.. */ if (likely(!isblk)) { if (unlikely(*pos >= inode->i_sb->s_maxbytes)) { if (*count || *pos > inode->i_sb->s_maxbytes) { |
1da177e4c Linux-2.6.12-rc2 |
2166 2167 2168 2169 2170 2171 2172 2173 |
return -EFBIG; } /* zero-length writes at ->s_maxbytes are OK */ } if (unlikely(*pos + *count > inode->i_sb->s_maxbytes)) *count = inode->i_sb->s_maxbytes - *pos; } else { |
9361401eb [PATCH] BLOCK: Ma... |
2174 |
#ifdef CONFIG_BLOCK |
1da177e4c Linux-2.6.12-rc2 |
2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 |
loff_t isize; if (bdev_read_only(I_BDEV(inode))) return -EPERM; isize = i_size_read(inode); if (*pos >= isize) { if (*count || *pos > isize) return -ENOSPC; } if (*pos + *count > isize) *count = isize - *pos; |
9361401eb [PATCH] BLOCK: Ma... |
2186 2187 2188 |
#else return -EPERM; #endif |
1da177e4c Linux-2.6.12-rc2 |
2189 2190 2191 2192 |
} return 0; } EXPORT_SYMBOL(generic_write_checks); |
afddba49d fs: introduce wri... |
2193 2194 2195 2196 2197 |
int pagecache_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { const struct address_space_operations *aops = mapping->a_ops; |
4e02ed4b4 fs: remove prepar... |
2198 |
return aops->write_begin(file, mapping, pos, len, flags, |
afddba49d fs: introduce wri... |
2199 |
pagep, fsdata); |
afddba49d fs: introduce wri... |
2200 2201 2202 2203 2204 2205 2206 2207 |
} EXPORT_SYMBOL(pagecache_write_begin); int pagecache_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { const struct address_space_operations *aops = mapping->a_ops; |
afddba49d fs: introduce wri... |
2208 |
|
4e02ed4b4 fs: remove prepar... |
2209 2210 |
mark_page_accessed(page); return aops->write_end(file, mapping, pos, len, copied, page, fsdata); |
afddba49d fs: introduce wri... |
2211 2212 |
} EXPORT_SYMBOL(pagecache_write_end); |
1da177e4c Linux-2.6.12-rc2 |
2213 2214 2215 2216 2217 2218 2219 2220 2221 |
ssize_t generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, unsigned long *nr_segs, loff_t pos, loff_t *ppos, size_t count, size_t ocount) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; ssize_t written; |
a969e903a kill generic_file... |
2222 2223 |
size_t write_len; pgoff_t end; |
1da177e4c Linux-2.6.12-rc2 |
2224 2225 2226 |
if (count != ocount) *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count); |
a969e903a kill generic_file... |
2227 2228 |
write_len = iov_length(iov, *nr_segs); end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT; |
a969e903a kill generic_file... |
2229 |
|
48b47c561 mm: direct IO sta... |
2230 |
written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1); |
a969e903a kill generic_file... |
2231 2232 2233 2234 2235 2236 2237 |
if (written) goto out; /* * After a write we want buffered reads to be sure to go to disk to get * the new data. We invalidate clean cached page from the region we're * about to write. We do this *before* the write so that we can return |
6ccfa806a VFS: fix dio writ... |
2238 |
* without clobbering -EIOCBQUEUED from ->direct_IO(). |
a969e903a kill generic_file... |
2239 2240 2241 2242 |
*/ if (mapping->nrpages) { written = invalidate_inode_pages2_range(mapping, pos >> PAGE_CACHE_SHIFT, end); |
6ccfa806a VFS: fix dio writ... |
2243 2244 2245 2246 2247 2248 2249 |
/* * If a page can not be invalidated, return 0 to fall back * to buffered write. */ if (written) { if (written == -EBUSY) return 0; |
a969e903a kill generic_file... |
2250 |
goto out; |
6ccfa806a VFS: fix dio writ... |
2251 |
} |
a969e903a kill generic_file... |
2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 |
} written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs); /* * Finally, try again to invalidate clean pages which might have been * cached by non-direct readahead, or faulted in by get_user_pages() * if the source of the write was an mmap'ed region of the file * we're writing. Either one is a pretty crazy thing to do, * so we don't support it 100%. If this invalidation * fails, tough, the write still worked... */ if (mapping->nrpages) { invalidate_inode_pages2_range(mapping, pos >> PAGE_CACHE_SHIFT, end); } |
1da177e4c Linux-2.6.12-rc2 |
2268 |
if (written > 0) { |
0116651c8 mm: remove tempor... |
2269 2270 2271 |
pos += written; if (pos > i_size_read(inode) && !S_ISBLK(inode->i_mode)) { i_size_write(inode, pos); |
1da177e4c Linux-2.6.12-rc2 |
2272 2273 |
mark_inode_dirty(inode); } |
0116651c8 mm: remove tempor... |
2274 |
*ppos = pos; |
1da177e4c Linux-2.6.12-rc2 |
2275 |
} |
a969e903a kill generic_file... |
2276 |
out: |
1da177e4c Linux-2.6.12-rc2 |
2277 2278 2279 |
return written; } EXPORT_SYMBOL(generic_file_direct_write); |
eb2be1893 mm: buffered writ... |
2280 2281 2282 2283 |
/* * Find or create a page at the given pagecache position. Return the locked * page. This function is specifically for buffered writes. */ |
54566b2c1 fs: symlink write... |
2284 2285 |
struct page *grab_cache_page_write_begin(struct address_space *mapping, pgoff_t index, unsigned flags) |
eb2be1893 mm: buffered writ... |
2286 2287 2288 |
{ int status; struct page *page; |
54566b2c1 fs: symlink write... |
2289 2290 2291 |
gfp_t gfp_notmask = 0; if (flags & AOP_FLAG_NOFS) gfp_notmask = __GFP_FS; |
eb2be1893 mm: buffered writ... |
2292 2293 |
repeat: page = find_lock_page(mapping, index); |
c585a2678 mm: remove likely... |
2294 |
if (page) |
3d08bcc88 mm: Wait for writ... |
2295 |
goto found; |
eb2be1893 mm: buffered writ... |
2296 |
|
54566b2c1 fs: symlink write... |
2297 |
page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~gfp_notmask); |
eb2be1893 mm: buffered writ... |
2298 2299 |
if (!page) return NULL; |
54566b2c1 fs: symlink write... |
2300 2301 |
status = add_to_page_cache_lru(page, mapping, index, GFP_KERNEL & ~gfp_notmask); |
eb2be1893 mm: buffered writ... |
2302 2303 2304 2305 2306 2307 |
if (unlikely(status)) { page_cache_release(page); if (status == -EEXIST) goto repeat; return NULL; } |
3d08bcc88 mm: Wait for writ... |
2308 2309 |
found: wait_on_page_writeback(page); |
eb2be1893 mm: buffered writ... |
2310 2311 |
return page; } |
54566b2c1 fs: symlink write... |
2312 |
EXPORT_SYMBOL(grab_cache_page_write_begin); |
eb2be1893 mm: buffered writ... |
2313 |
|
afddba49d fs: introduce wri... |
2314 2315 2316 2317 2318 2319 2320 |
static ssize_t generic_perform_write(struct file *file, struct iov_iter *i, loff_t pos) { struct address_space *mapping = file->f_mapping; const struct address_space_operations *a_ops = mapping->a_ops; long status = 0; ssize_t written = 0; |
674b892ed mm: restore KERNE... |
2321 2322 2323 2324 2325 2326 2327 |
unsigned int flags = 0; /* * Copies from kernel address space cannot fail (NFSD is a big user). */ if (segment_eq(get_fs(), KERNEL_DS)) flags |= AOP_FLAG_UNINTERRUPTIBLE; |
afddba49d fs: introduce wri... |
2328 2329 2330 |
do { struct page *page; |
afddba49d fs: introduce wri... |
2331 2332 2333 2334 2335 2336 |
unsigned long offset; /* Offset into pagecache page */ unsigned long bytes; /* Bytes to write to page */ size_t copied; /* Bytes copied from user */ void *fsdata; offset = (pos & (PAGE_CACHE_SIZE - 1)); |
afddba49d fs: introduce wri... |
2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 |
bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset, iov_iter_count(i)); again: /* * Bring in the user page that we will copy from _first_. * Otherwise there's a nasty deadlock on copying from the * same page as we're writing to, without it being marked * up-to-date. * * Not only is this an optimisation, but it is also required * to check that the address is actually valid, when atomic * usercopies are used, below. */ if (unlikely(iov_iter_fault_in_readable(i, bytes))) { status = -EFAULT; break; } |
674b892ed mm: restore KERNE... |
2356 |
status = a_ops->write_begin(file, mapping, pos, bytes, flags, |
afddba49d fs: introduce wri... |
2357 2358 2359 |
&page, &fsdata); if (unlikely(status)) break; |
931e80e4b mm: flush dcache ... |
2360 2361 |
if (mapping_writably_mapped(mapping)) flush_dcache_page(page); |
afddba49d fs: introduce wri... |
2362 2363 2364 2365 |
pagefault_disable(); copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes); pagefault_enable(); flush_dcache_page(page); |
c8236db9c mm: mark page acc... |
2366 |
mark_page_accessed(page); |
afddba49d fs: introduce wri... |
2367 2368 2369 2370 2371 2372 2373 |
status = a_ops->write_end(file, mapping, pos, bytes, copied, page, fsdata); if (unlikely(status < 0)) break; copied = status; cond_resched(); |
124d3b704 fix writev regres... |
2374 |
iov_iter_advance(i, copied); |
afddba49d fs: introduce wri... |
2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 |
if (unlikely(copied == 0)) { /* * If we were unable to copy any data at all, we must * fall back to a single segment length write. * * If we didn't fallback here, we could livelock * because not all segments in the iov can be copied at * once without a pagefault. */ bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset, iov_iter_single_seg_count(i)); goto again; } |
afddba49d fs: introduce wri... |
2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 |
pos += copied; written += copied; balance_dirty_pages_ratelimited(mapping); } while (iov_iter_count(i)); return written ? written : status; } ssize_t generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos, loff_t *ppos, size_t count, ssize_t written) { struct file *file = iocb->ki_filp; |
afddba49d fs: introduce wri... |
2404 2405 2406 2407 |
ssize_t status; struct iov_iter i; iov_iter_init(&i, iov, nr_segs, count, written); |
4e02ed4b4 fs: remove prepar... |
2408 |
status = generic_perform_write(file, &i, pos); |
1da177e4c Linux-2.6.12-rc2 |
2409 |
|
1da177e4c Linux-2.6.12-rc2 |
2410 |
if (likely(status >= 0)) { |
afddba49d fs: introduce wri... |
2411 2412 |
written += status; *ppos = pos + status; |
1da177e4c Linux-2.6.12-rc2 |
2413 2414 |
} |
1da177e4c Linux-2.6.12-rc2 |
2415 2416 2417 |
return written ? written : status; } EXPORT_SYMBOL(generic_file_buffered_write); |
e4dd9de3c vfs: Export __gen... |
2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 |
/** * __generic_file_aio_write - write data to a file * @iocb: IO state structure (file, offset, etc.) * @iov: vector with data to write * @nr_segs: number of segments in the vector * @ppos: position where to write * * This function does all the work needed for actually writing data to a * file. It does all basic checks, removes SUID from the file, updates * modification times and calls proper subroutines depending on whether we * do direct IO or a standard buffered write. * * It expects i_mutex to be grabbed unless we work on a block device or similar * object which does not need locking at all. * * This function does *not* take care of syncing data in case of O_SYNC write. * A caller has to handle it. This is mainly due to the fact that we want to * avoid syncing under i_mutex. */ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t *ppos) |
1da177e4c Linux-2.6.12-rc2 |
2439 2440 |
{ struct file *file = iocb->ki_filp; |
fb5527e68 [PATCH] direct-io... |
2441 |
struct address_space * mapping = file->f_mapping; |
1da177e4c Linux-2.6.12-rc2 |
2442 2443 2444 |
size_t ocount; /* original count */ size_t count; /* after file limit checks */ struct inode *inode = mapping->host; |
1da177e4c Linux-2.6.12-rc2 |
2445 2446 2447 2448 2449 |
loff_t pos; ssize_t written; ssize_t err; ocount = 0; |
0ceb33143 mm: move common s... |
2450 2451 2452 |
err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); if (err) return err; |
1da177e4c Linux-2.6.12-rc2 |
2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 |
count = ocount; pos = *ppos; vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); /* We can write back this queue in page reclaim */ current->backing_dev_info = mapping->backing_dev_info; written = 0; err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); if (err) goto out; if (count == 0) goto out; |
2f1936b87 [patch 3/5] vfs: ... |
2469 |
err = file_remove_suid(file); |
1da177e4c Linux-2.6.12-rc2 |
2470 2471 |
if (err) goto out; |
870f48179 [PATCH] replace i... |
2472 |
file_update_time(file); |
1da177e4c Linux-2.6.12-rc2 |
2473 2474 2475 |
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (unlikely(file->f_flags & O_DIRECT)) { |
fb5527e68 [PATCH] direct-io... |
2476 2477 2478 2479 2480 |
loff_t endbyte; ssize_t written_buffered; written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos, count, ocount); |
1da177e4c Linux-2.6.12-rc2 |
2481 2482 2483 2484 2485 2486 2487 2488 |
if (written < 0 || written == count) goto out; /* * direct-io write to a hole: fall through to buffered I/O * for completing the rest of the request. */ pos += written; count -= written; |
fb5527e68 [PATCH] direct-io... |
2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 |
written_buffered = generic_file_buffered_write(iocb, iov, nr_segs, pos, ppos, count, written); /* * If generic_file_buffered_write() retuned a synchronous error * then we want to return the number of bytes which were * direct-written, or the error code if that was zero. Note * that this differs from normal direct-io semantics, which * will return -EFOO even if some bytes were written. */ if (written_buffered < 0) { err = written_buffered; goto out; } |
1da177e4c Linux-2.6.12-rc2 |
2503 |
|
fb5527e68 [PATCH] direct-io... |
2504 2505 2506 2507 2508 2509 |
/* * We need to ensure that the page cache pages are written to * disk and invalidated to preserve the expected O_DIRECT * semantics. */ endbyte = pos + written_buffered - written - 1; |
c05c4edd8 direct I/O fallba... |
2510 |
err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte); |
fb5527e68 [PATCH] direct-io... |
2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 |
if (err == 0) { written = written_buffered; invalidate_mapping_pages(mapping, pos >> PAGE_CACHE_SHIFT, endbyte >> PAGE_CACHE_SHIFT); } else { /* * We don't know how much we wrote, so just return * the number of bytes which were direct-written */ } } else { written = generic_file_buffered_write(iocb, iov, nr_segs, pos, ppos, count, written); } |
1da177e4c Linux-2.6.12-rc2 |
2526 2527 2528 2529 |
out: current->backing_dev_info = NULL; return written ? written : err; } |
e4dd9de3c vfs: Export __gen... |
2530 |
EXPORT_SYMBOL(__generic_file_aio_write); |
e4dd9de3c vfs: Export __gen... |
2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 |
/** * generic_file_aio_write - write data to a file * @iocb: IO state structure * @iov: vector with data to write * @nr_segs: number of segments in the vector * @pos: position in file where to write * * This is a wrapper around __generic_file_aio_write() to be used by most * filesystems. It takes care of syncing the file in case of O_SYNC file * and acquires i_mutex as needed. */ |
027445c37 [PATCH] Vectorize... |
2542 2543 |
ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos) |
1da177e4c Linux-2.6.12-rc2 |
2544 2545 |
{ struct file *file = iocb->ki_filp; |
148f948ba vfs: Introduce ne... |
2546 |
struct inode *inode = file->f_mapping->host; |
55602dd66 fs: make generic ... |
2547 |
struct blk_plug plug; |
1da177e4c Linux-2.6.12-rc2 |
2548 |
ssize_t ret; |
1da177e4c Linux-2.6.12-rc2 |
2549 2550 |
BUG_ON(iocb->ki_pos != pos); |
1b1dcc1b5 [PATCH] mutex sub... |
2551 |
mutex_lock(&inode->i_mutex); |
55602dd66 fs: make generic ... |
2552 |
blk_start_plug(&plug); |
e4dd9de3c vfs: Export __gen... |
2553 |
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); |
1b1dcc1b5 [PATCH] mutex sub... |
2554 |
mutex_unlock(&inode->i_mutex); |
1da177e4c Linux-2.6.12-rc2 |
2555 |
|
148f948ba vfs: Introduce ne... |
2556 |
if (ret > 0 || ret == -EIOCBQUEUED) { |
1da177e4c Linux-2.6.12-rc2 |
2557 |
ssize_t err; |
148f948ba vfs: Introduce ne... |
2558 |
err = generic_write_sync(file, pos, ret); |
c7b50db21 vfs: Remove synci... |
2559 |
if (err < 0 && ret > 0) |
1da177e4c Linux-2.6.12-rc2 |
2560 2561 |
ret = err; } |
55602dd66 fs: make generic ... |
2562 |
blk_finish_plug(&plug); |
1da177e4c Linux-2.6.12-rc2 |
2563 2564 2565 |
return ret; } EXPORT_SYMBOL(generic_file_aio_write); |
cf9a2ae8d [PATCH] BLOCK: Mo... |
2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 |
/** * try_to_release_page() - release old fs-specific metadata on a page * * @page: the page which the kernel is trying to free * @gfp_mask: memory allocation flags (and I/O mode) * * The address_space is to try to release any data against the page * (presumably at page->private). If the release was successful, return `1'. * Otherwise return zero. * |
266cf658e FS-Cache: Recruit... |
2576 2577 2578 |
* This may also be called if PG_fscache is set on a page, indicating that the * page is known to the local caching routines. * |
cf9a2ae8d [PATCH] BLOCK: Mo... |
2579 |
* The @gfp_mask argument specifies whether I/O may be performed to release |
3f31fddfa jbd: fix race bet... |
2580 |
* this page (__GFP_IO), and whether the call may block (__GFP_WAIT & __GFP_FS). |
cf9a2ae8d [PATCH] BLOCK: Mo... |
2581 |
* |
cf9a2ae8d [PATCH] BLOCK: Mo... |
2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 |
*/ int try_to_release_page(struct page *page, gfp_t gfp_mask) { struct address_space * const mapping = page->mapping; BUG_ON(!PageLocked(page)); if (PageWriteback(page)) return 0; if (mapping && mapping->a_ops->releasepage) return mapping->a_ops->releasepage(page, gfp_mask); return try_to_free_buffers(page); } EXPORT_SYMBOL(try_to_release_page); |