cregit-Linux how code gets into the kernel

Release 4.11 mm/truncate.c

Directory: mm
/*
 * mm/truncate.c - code for taking down pages from address_spaces
 *
 * Copyright (C) 2002, Linus Torvalds
 *
 * 10Sep2002    Andrew Morton
 *              Initial version.
 */

#include <linux/kernel.h>
#include <linux/backing-dev.h>
#include <linux/dax.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/export.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/pagevec.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/buffer_head.h>	/* grr. try_to_release_page,
                                   do_invalidatepage */
#include <linux/shmem_fs.h>
#include <linux/cleancache.h>
#include <linux/rmap.h>
#include "internal.h"


static void clear_shadow_entry(struct address_space *mapping, pgoff_t index, void *entry) { struct radix_tree_node *node; void **slot; spin_lock_irq(&mapping->tree_lock); /* * Regular page slots are stabilized by the page lock even * without the tree itself locked. These unlocked entries * need verification under the tree lock. */ if (!__radix_tree_lookup(&mapping->page_tree, index, &node, &slot)) goto unlock; if (*slot != entry) goto unlock; __radix_tree_replace(&mapping->page_tree, node, slot, NULL, workingset_update_node, mapping); mapping->nrexceptional--; unlock: spin_unlock_irq(&mapping->tree_lock); }

Contributors

PersonTokensPropCommitsCommitProp
Johannes Weiner9189.22%562.50%
Jan Kara76.86%225.00%
Ross Zwisler43.92%112.50%
Total102100.00%8100.00%

/* * Unconditionally remove exceptional entry. Usually called from truncate path. */
static void truncate_exceptional_entry(struct address_space *mapping, pgoff_t index, void *entry) { /* Handled by shmem itself */ if (shmem_mapping(mapping)) return; if (dax_mapping(mapping)) { dax_delete_mapping_entry(mapping, index); return; } clear_shadow_entry(mapping, index, entry); }

Contributors

PersonTokensPropCommitsCommitProp
Jan Kara53100.00%1100.00%
Total53100.00%1100.00%

/* * Invalidate exceptional entry if easily possible. This handles exceptional * entries for invalidate_inode_pages() so for DAX it evicts only unlocked and * clean entries. */
static int invalidate_exceptional_entry(struct address_space *mapping, pgoff_t index, void *entry) { /* Handled by shmem itself */ if (shmem_mapping(mapping)) return 1; if (dax_mapping(mapping)) return dax_invalidate_mapping_entry(mapping, index); clear_shadow_entry(mapping, index, entry); return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Jan Kara56100.00%1100.00%
Total56100.00%1100.00%

/* * Invalidate exceptional entry if clean. This handles exceptional entries for * invalidate_inode_pages2() so for DAX it evicts only clean entries. */
static int invalidate_exceptional_entry2(struct address_space *mapping, pgoff_t index, void *entry) { /* Handled by shmem itself */ if (shmem_mapping(mapping)) return 1; if (dax_mapping(mapping)) return dax_invalidate_mapping_entry_sync(mapping, index); clear_shadow_entry(mapping, index, entry); return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Jan Kara56100.00%1100.00%
Total56100.00%1100.00%

/** * do_invalidatepage - invalidate part or all of a page * @page: the page which is affected * @offset: start of the range to invalidate * @length: length of the range to invalidate * * do_invalidatepage() is called when all or part of the page has become * invalidated by a truncate operation. * * do_invalidatepage() does not have to release all buffers, but it must * ensure that no dirty buffer is left outside @offset and that no I/O * is underway against any of the blocks which are outside the truncation * point. Because the caller is about to free (and possibly reuse) those * blocks on-disk. */
void do_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { void (*invalidatepage)(struct page *, unsigned int, unsigned int); invalidatepage = page->mapping->a_ops->invalidatepage; #ifdef CONFIG_BLOCK if (!invalidatepage) invalidatepage = block_invalidatepage; #endif if (invalidatepage) (*invalidatepage)(page, offset, length); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells6485.33%266.67%
Lukas Czerner1114.67%133.33%
Total75100.00%3100.00%

/* * If truncate cannot remove the fs-private metadata from the page, the page * becomes orphaned. It will be left on the LRU and may even be mapped into * user pagetables if we're racing with filemap_fault(). * * We need to bale out if page->mapping is no longer equal to the original * mapping. This happens a) when the VM reclaimed the page while we waited on * its lock, b) when a concurrent invalidate_mapping_pages got there first and * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. */
static int truncate_complete_page(struct address_space *mapping, struct page *page) { if (page->mapping != mapping) return -EIO; if (page_has_private(page)) do_invalidatepage(page, 0, PAGE_SIZE); /* * Some filesystems seem to re-dirty the page even after * the VM has canceled the dirty bit (eg ext3 journaling). * Hence dirty accounting check is placed after invalidation. */ cancel_dirty_page(page); ClearPageMappedToDisk(page); delete_from_page_cache(page); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton4469.84%325.00%
Nicholas Piggin914.29%216.67%
Björn Steinbrink46.35%18.33%
Kirill A. Shutemov11.59%18.33%
MinChan Kim11.59%18.33%
Konstantin Khlebnikov11.59%18.33%
David Howells11.59%18.33%
Tejun Heo11.59%18.33%
Lukas Czerner11.59%18.33%
Total63100.00%12100.00%

/* * This is for invalidate_mapping_pages(). That function can be called at * any time, and is not supposed to throw away dirty pages. But pages can * be marked dirty at any time too, so use remove_mapping which safely * discards clean, unused pages. * * Returns non-zero if the page was successfully invalidated. */
static int invalidate_complete_page(struct address_space *mapping, struct page *page) { int ret; if (page->mapping != mapping) return 0; if (page_has_private(page) && !try_to_release_page(page, 0)) return 0; ret = remove_mapping(mapping, page); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton5185.00%466.67%
Nicholas Piggin813.33%116.67%
David Howells11.67%116.67%
Total60100.00%6100.00%


int truncate_inode_page(struct address_space *mapping, struct page *page) { loff_t holelen; VM_BUG_ON_PAGE(PageTail(page), page); holelen = PageTransHuge(page) ? HPAGE_PMD_SIZE : PAGE_SIZE; if (page_mapped(page)) { unmap_mapping_range(mapping, (loff_t)page->index << PAGE_SHIFT, holelen, 0); } return truncate_complete_page(mapping, page); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin4864.86%133.33%
Kirill A. Shutemov2635.14%266.67%
Total74100.00%3100.00%

/* * Used to get rid of pages on hardware memory corruption. */
int generic_error_remove_page(struct address_space *mapping, struct page *page) { if (!mapping) return -EINVAL; /* * Only punch for normal data pages for now. * Handling other types like directories would need more auditing. */ if (!S_ISREG(mapping->host->i_mode)) return -EIO; return truncate_inode_page(mapping, page); }

Contributors

PersonTokensPropCommitsCommitProp
Andi Kleen49100.00%1100.00%
Total49100.00%1100.00%

EXPORT_SYMBOL(generic_error_remove_page); /* * Safely invalidate one page from its pagecache mapping. * It only drops clean, unused pages. The page must be locked. * * Returns 1 if the page is successfully invalidated, otherwise 0. */
int invalidate_inode_page(struct page *page) { struct address_space *mapping = page_mapping(page); if (!mapping) return 0; if (PageDirty(page) || PageWriteback(page)) return 0; if (page_mapped(page)) return 0; return invalidate_complete_page(mapping, page); }

Contributors

PersonTokensPropCommitsCommitProp
Fengguang Wu61100.00%1100.00%
Total61100.00%1100.00%

/** * truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets * @mapping: mapping to truncate * @lstart: offset from which to truncate * @lend: offset to which to truncate (inclusive) * * Truncate the page cache, removing the pages that are between * specified offsets (and zeroing out partial pages * if lstart or lend + 1 is not page aligned). * * Truncate takes two passes - the first pass is nonblocking. It will not * block on page locks and it will not block on writeback. The second pass * will wait. This is to prevent as much IO as possible in the affected region. * The first pass will remove most pages, so the search cost of the second pass * is low. * * We pass down the cache-hot hint to the page freeing code. Even if the * mapping is large, it is probably the case that the final pages are the most * recently touched, and freeing happens in ascending file offset order. * * Note that since ->invalidatepage() accepts range to invalidate * truncate_inode_pages_range is able to handle cases where lend + 1 is not * page aligned properly. */
void truncate_inode_pages_range(struct address_space *mapping, loff_t lstart, loff_t lend) { pgoff_t start; /* inclusive */ pgoff_t end; /* exclusive */ unsigned int partial_start; /* inclusive */ unsigned int partial_end; /* exclusive */ struct pagevec pvec; pgoff_t indices[PAGEVEC_SIZE]; pgoff_t index; int i; cleancache_invalidate_inode(mapping); if (mapping->nrpages == 0 && mapping->nrexceptional == 0) return; /* Offsets within partial pages */ partial_start = lstart & (PAGE_SIZE - 1); partial_end = (lend + 1) & (PAGE_SIZE - 1); /* * 'start' and 'end' always covers the range of pages to be fully * truncated. Partial pages are covered with 'partial_start' at the * start of the range and 'partial_end' at the end of the range. * Note that 'end' is exclusive while 'lend' is inclusive. */ start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT; if (lend == -1) /* * lend == -1 indicates end-of-file so we have to set 'end' * to the highest possible pgoff_t and since the type is * unsigned we're using -1. */ end = -1; else end = (lend + 1) >> PAGE_SHIFT; pagevec_init(&pvec, 0); index = start; while (index < end && pagevec_lookup_entries(&pvec, mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE), indices)) { for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; /* We rely upon deletion not changing page->index */ index = indices[i]; if (index >= end) break; if (radix_tree_exceptional_entry(page)) { truncate_exceptional_entry(mapping, index, page); continue; } if (!trylock_page(page)) continue; WARN_ON(page_to_index(page) != index); if (PageWriteback(page)) { unlock_page(page); continue; } truncate_inode_page(mapping, page); unlock_page(page); } pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); cond_resched(); index++; } if (partial_start) { struct page *page = find_lock_page(mapping, start - 1); if (page) { unsigned int top = PAGE_SIZE; if (start > end) { /* Truncation within a single page */ top = partial_end; partial_end = 0; } wait_on_page_writeback(page); zero_user_segment(page, partial_start, top); cleancache_invalidate_page(mapping, page); if (page_has_private(page)) do_invalidatepage(page, partial_start, top - partial_start); unlock_page(page); put_page(page); } } if (partial_end) { struct page *page = find_lock_page(mapping, end); if (page) { wait_on_page_writeback(page); zero_user_segment(page, 0, partial_end); cleancache_invalidate_page(mapping, page); if (page_has_private(page)) do_invalidatepage(page, 0, partial_end); unlock_page(page); put_page(page); } } /* * If the truncation happened within a single page no pages * will be released, just zeroed, so we can bail out now. */ if (start >= end) return; index = start; for ( ; ; ) { cond_resched(); if (!pagevec_lookup_entries(&pvec, mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE), indices)) { /* If all gone from start onwards, we're done */ if (index == start) break; /* Otherwise restart to make sure all gone */ index = start; continue; } if (index == start && indices[0] >= end) { /* All gone out of hole to be punched, we're done */ pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); break; } for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; /* We rely upon deletion not changing page->index */ index = indices[i]; if (index >= end) { /* Restart punch to make sure all gone */ index = start - 1; break; } if (radix_tree_exceptional_entry(page)) { truncate_exceptional_entry(mapping, index, page); continue; } lock_page(page); WARN_ON(page_to_index(page) != index); wait_on_page_writeback(page); truncate_inode_page(mapping, page); unlock_page(page); } pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); index++; } cleancache_invalidate_inode(mapping); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton26838.62%522.73%
Lukas Czerner18626.80%14.55%
Johannes Weiner8011.53%29.09%
Hugh Dickins7711.10%313.64%
Hans Reiser466.63%14.55%
Kirill A. Shutemov142.02%313.64%
Nicholas Piggin101.44%313.64%
Dan Magenheimer101.44%29.09%
Jan Kara20.29%14.55%
Ross Zwisler10.14%14.55%
Total694100.00%22100.00%

EXPORT_SYMBOL(truncate_inode_pages_range); /** * truncate_inode_pages - truncate *all* the pages from an offset * @mapping: mapping to truncate * @lstart: offset from which to truncate * * Called under (and serialised by) inode->i_mutex. * * Note: When this function returns, there can be a page in the process of * deletion (inside __delete_from_page_cache()) in the specified range. Thus * mapping->nrpages can be non-zero when this function returns even after * truncation of the whole mapping. */
void truncate_inode_pages(struct address_space *mapping, loff_t lstart) { truncate_inode_pages_range(mapping, lstart, (loff_t)-1); }

Contributors

PersonTokensPropCommitsCommitProp
Hans Reiser26100.00%1100.00%
Total26100.00%1100.00%

EXPORT_SYMBOL(truncate_inode_pages); /** * truncate_inode_pages_final - truncate *all* pages before inode dies * @mapping: mapping to truncate * * Called under (and serialized by) inode->i_mutex. * * Filesystems have to use this in the .evict_inode path to inform the * VM that this is the final truncate and the inode is going away. */
void truncate_inode_pages_final(struct address_space *mapping) { unsigned long nrexceptional; unsigned long nrpages; /* * Page reclaim can not participate in regular inode lifetime * management (can't call iput()) and thus can race with the * inode teardown. Tell it when the address space is exiting, * so that it does not install eviction information after the * final truncate has begun. */ mapping_set_exiting(mapping); /* * When reclaim installs eviction entries, it increases * nrexceptional first, then decreases nrpages. Make sure we see * this in the right order or we might miss an entry. */ nrpages = mapping->nrpages; smp_rmb(); nrexceptional = mapping->nrexceptional; if (nrpages || nrexceptional) { /* * As truncation uses a lockless tree lookup, cycle * the tree lock to make sure any ongoing tree * modification that does not see AS_EXITING is * completed before starting the final truncate. */ spin_lock_irq(&mapping->tree_lock); spin_unlock_irq(&mapping->tree_lock); truncate_inode_pages(mapping, 0); } }

Contributors

PersonTokensPropCommitsCommitProp
Johannes Weiner6793.06%150.00%
Ross Zwisler56.94%150.00%
Total72100.00%2100.00%

EXPORT_SYMBOL(truncate_inode_pages_final); /** * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode * @mapping: the address_space which holds the pages to invalidate * @start: the offset 'from' which to invalidate * @end: the offset 'to' which to invalidate (inclusive) * * This function only removes the unlocked pages, if you want to * remove all the pages of one inode, you must call truncate_inode_pages. * * invalidate_mapping_pages() will not block on IO activity. It will not * invalidate pages which are dirty, locked, under writeback or mapped into * pagetables. */
unsigned long invalidate_mapping_pages(struct address_space *mapping, pgoff_t start, pgoff_t end) { pgoff_t indices[PAGEVEC_SIZE]; struct pagevec pvec; pgoff_t index = start; unsigned long ret; unsigned long count = 0; int i; pagevec_init(&pvec, 0); while (index <= end && pagevec_lookup_entries(&pvec, mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1, indices)) { for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; /* We rely upon deletion not changing page->index */ index = indices[i]; if (index > end) break; if (radix_tree_exceptional_entry(page)) { invalidate_exceptional_entry(mapping, index, page); continue; } if (!trylock_page(page)) continue; WARN_ON(page_to_index(page) != index); /* Middle of THP: skip */ if (PageTransTail(page)) { unlock_page(page); continue; } else if (PageTransHuge(page)) { index += HPAGE_PMD_NR - 1; i += HPAGE_PMD_NR - 1; /* 'end' is in the middle of THP */ if (index == round_down(end, HPAGE_PMD_NR)) continue; } ret = invalidate_inode_page(page); unlock_page(page); /* * Invalidation is a hint that the page is no longer * of interest and try to speed up its reclaim. */ if (!ret) deactivate_file_page(page); count += ret; } pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); cond_resched(); index++; } return count; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton11441.91%637.50%
Kirill A. Shutemov5419.85%212.50%
Johannes Weiner3713.60%16.25%
Hugh Dickins3512.87%16.25%
MinChan Kim217.72%212.50%
Neil Brown82.94%16.25%
Mike Waychison10.37%16.25%
Jan Kara10.37%16.25%
Fengguang Wu10.37%16.25%
Total272100.00%16100.00%

EXPORT_SYMBOL(invalidate_mapping_pages); /* * This is like invalidate_complete_page(), except it ignores the page's * refcount. We do this because invalidate_inode_pages2() needs stronger * invalidation guarantees, and cannot afford to leave pages behind because * shrink_page_list() has a temp ref on them, or because they're transiently * sitting in the lru_cache_add() pagevecs. */
static int invalidate_complete_page2(struct address_space *mapping, struct page *page) { unsigned long flags; if (page->mapping != mapping) return 0; if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return 0; spin_lock_irqsave(&mapping->tree_lock, flags); if (PageDirty(page)) goto failed; BUG_ON(page_has_private(page)); __delete_from_page_cache(page, NULL); spin_unlock_irqrestore(&mapping->tree_lock, flags); if (mapping->a_ops->freepage) mapping->a_ops->freepage(page); put_page(page); /* pagecache ref */ return 1; failed: spin_unlock_irqrestore(&mapping->tree_lock, flags); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton9469.63%112.50%
Linus Torvalds1712.59%112.50%
Greg Thelen1712.59%112.50%
David Howells21.48%112.50%
Johannes Weiner21.48%112.50%
Trond Myklebust10.74%112.50%
MinChan Kim10.74%112.50%
Kirill A. Shutemov10.74%112.50%
Total135100.00%8100.00%


static int do_launder_page(struct address_space *mapping, struct page *page) { if (!PageDirty(page)) return 0; if (page->mapping != mapping || mapping->a_ops->launder_page == NULL) return 0; return mapping->a_ops->launder_page(page); }

Contributors

PersonTokensPropCommitsCommitProp
Trond Myklebust56100.00%1100.00%
Total56100.00%1100.00%

/** * invalidate_inode_pages2_range - remove range of pages from an address_space * @mapping: the address_space * @start: the page offset 'from' which to invalidate * @end: the page offset 'to' which to invalidate (inclusive) * * Any pages which are found to be mapped into pagetables are unmapped prior to * invalidation. * * Returns -EBUSY if any pages could not be invalidated. */
int invalidate_inode_pages2_range(struct address_space *mapping, pgoff_t start, pgoff_t end) { pgoff_t indices[PAGEVEC_SIZE]; struct pagevec pvec; pgoff_t index; int i; int ret = 0; int ret2 = 0; int did_range_unmap = 0; cleancache_invalidate_inode(mapping); pagevec_init(&pvec, 0); index = start; while (index <= end && pagevec_lookup_entries(&pvec, mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1, indices)) { for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; /* We rely upon deletion not changing page->index */ index = indices[i]; if (index > end) break; if (radix_tree_exceptional_entry(page)) { if (!invalidate_exceptional_entry2(mapping, index, page)) ret = -EBUSY; continue; } lock_page(page); WARN_ON(page_to_index(page) != index); if (page->mapping != mapping) { unlock_page(page); continue; } wait_on_page_writeback(page); if (page_mapped(page)) { if (!did_range_unmap) { /* * Zap the rest of the file in one hit. */ unmap_mapping_range(mapping, (loff_t)index << PAGE_SHIFT, (loff_t)(1 + end - index) << PAGE_SHIFT, 0); did_range_unmap = 1; } else { /* * Just zap this page */ unmap_mapping_range(mapping, (loff_t)index << PAGE_SHIFT, PAGE_SIZE, 0); } } BUG_ON(page_mapped(page)); ret2 = do_launder_page(mapping, page); if (ret2 == 0) { if (!invalidate_complete_page2(mapping, page)) ret2 = -EBUSY; } if (ret2 < 0) ret = ret2; unlock_page(page); } pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); cond_resched(); index++; } cleancache_invalidate_inode(mapping); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton15443.02%627.27%
Johannes Weiner3710.34%14.55%
Zach Brown3610.06%14.55%
Hugh Dickins328.94%14.55%
Hisashi Hifumi246.70%29.09%
Stephen C. Tweedie154.19%14.55%
Oleg Drokin113.07%14.55%
Dan Magenheimer102.79%29.09%
Trond Myklebust102.79%14.55%
Nicholas Piggin92.51%14.55%
Jan Kara92.51%14.55%
Kirill A. Shutemov71.96%313.64%
Jens Axboe41.12%14.55%
Total358100.00%22100.00%

EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range); /** * invalidate_inode_pages2 - remove all pages from an address_space * @mapping: the address_space * * Any pages which are found to be mapped into pagetables are unmapped prior to * invalidation. * * Returns -EBUSY if any pages could not be invalidated. */
int invalidate_inode_pages2(struct address_space *mapping) { return invalidate_inode_pages2_range(mapping, 0, -1); }

Contributors

PersonTokensPropCommitsCommitProp
Zach Brown21100.00%1100.00%
Total21100.00%1100.00%

EXPORT_SYMBOL_GPL(invalidate_inode_pages2); /** * truncate_pagecache - unmap and remove pagecache that has been truncated * @inode: inode * @newsize: new file size * * inode's new i_size must already be written before truncate_pagecache * is called. * * This function should typically be called before the filesystem * releases resources associated with the freed range (eg. deallocates * blocks). This way, pagecache will always stay logically coherent * with on-disk format, and the filesystem would not have to deal with * situations such as writepage being called for a page that has already * had its underlying blocks deallocated. */
void truncate_pagecache(struct inode *inode, loff_t newsize) { struct address_space *mapping = inode->i_mapping; loff_t holebegin = round_up(newsize, PAGE_SIZE); /* * unmap_mapping_range is called twice, first simply for * efficiency so that truncate_inode_pages does fewer * single-page unmaps. However after this first call, and * before truncate_inode_pages finishes, it is possible for * private pages to be COWed, which remain after * truncate_inode_pages finishes, hence the second * unmap_mapping_range call must be made for correctness. */ unmap_mapping_range(mapping, holebegin, 0, 1); truncate_inode_pages(mapping, newsize); unmap_mapping_range(mapping, holebegin, 0, 1); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin4775.81%133.33%
Hugh Dickins1422.58%133.33%
Hirofumi Ogawa11.61%133.33%
Total62100.00%3100.00%

EXPORT_SYMBOL(truncate_pagecache); /** * truncate_setsize - update inode and pagecache for a new file size * @inode: inode * @newsize: new file size * * truncate_setsize updates i_size and performs pagecache truncation (if * necessary) to @newsize. It will be typically be called from the filesystem's * setattr function when ATTR_SIZE is passed in. * * Must be called with a lock serializing truncates and writes (generally * i_mutex but e.g. xfs uses a different lock) and before all filesystem * specific block truncation has been performed. */
void truncate_setsize(struct inode *inode, loff_t newsize) { loff_t oldsize = inode->i_size; i_size_write(inode, newsize); if (newsize > oldsize) pagecache_isize_extended(inode, oldsize, newsize); truncate_pagecache(inode, newsize); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig2755.10%150.00%
Jan Kara2244.90%150.00%
Total49100.00%2100.00%

EXPORT_SYMBOL(truncate_setsize); /** * pagecache_isize_extended - update pagecache after extension of i_size * @inode: inode for which i_size was extended * @from: original inode size * @to: new inode size * * Handle extension of inode size either caused by extending truncate or by * write starting after current i_size. We mark the page straddling current * i_size RO so that page_mkwrite() is called on the nearest write access to * the page. This way filesystem can be sure that page_mkwrite() is called on * the page before user writes to the page via mmap after the i_size has been * changed. * * The function must be called after i_size is updated so that page fault * coming after we unlock the page will already see the new i_size. * The function must be called while we still hold i_mutex - this not only * makes sure i_size is stable but also that userspace cannot observe new * i_size value before we are prepared to store mmap writes at new inode size. */
void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to) { int bsize = i_blocksize(inode); loff_t rounded_from; struct page *page; pgoff_t index; WARN_ON(to > inode->i_size); if (from >= to || bsize == PAGE_SIZE) return; /* Page straddling @from will not have any hole block created? */ rounded_from = round_up(from, bsize); if (to <= rounded_from || !(rounded_from & (PAGE_SIZE - 1))) return; index = from >> PAGE_SHIFT; page = find_lock_page(inode->i_mapping, index); /* Page not cached? Nothing to do */ if (!page) return; /* * See clear_page_dirty_for_io() for details why set_page_dirty() * is needed. */ if (page_mkclean(page)) set_page_dirty(page); unlock_page(page); put_page(page); }

Contributors

PersonTokensPropCommitsCommitProp
Jan Kara12394.62%133.33%
Kirill A. Shutemov43.08%133.33%
Fabian Frederick32.31%133.33%
Total130100.00%3100.00%

EXPORT_SYMBOL(pagecache_isize_extended); /** * truncate_pagecache_range - unmap and remove pagecache that is hole-punched * @inode: inode * @lstart: offset of beginning of hole * @lend: offset of last byte of hole * * This function should typically be called before the filesystem * releases resources associated with the freed range (eg. deallocates * blocks). This way, pagecache will always stay logically coherent * with on-disk format, and the filesystem would not have to deal with * situations such as writepage being called for a page that has already * had its underlying blocks deallocated. */
void truncate_pagecache_range(struct inode *inode, loff_t lstart, loff_t lend) { struct address_space *mapping = inode->i_mapping; loff_t unmap_start = round_up(lstart, PAGE_SIZE); loff_t unmap_end = round_down(1 + lend, PAGE_SIZE) - 1; /* * This rounding is currently just for example: unmap_mapping_range * expands its hole outwards, whereas we want it to contract the hole * inwards. However, existing callers of truncate_pagecache_range are * doing their own page rounding first. Note that unmap_mapping_range * allows holelen 0 for all, and we allow lend -1 for end of file. */ /* * Unlike in truncate_pagecache, unmap_mapping_range is called only * once (before truncating pagecache), and without "even_cows" flag: * hole-punching should not remove private COWed pages from the hole. */ if ((u64)unmap_end > (u64)unmap_start) unmap_mapping_range(mapping, unmap_start, 1 + unmap_end - unmap_start, 0); truncate_inode_pages_range(mapping, lstart, lend); }

Contributors

PersonTokensPropCommitsCommitProp
Hugh Dickins8698.85%150.00%
Lukas Czerner11.15%150.00%
Total87100.00%2100.00%

EXPORT_SYMBOL(truncate_pagecache_range);

Overall Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton74427.20%1517.44%
Jan Kara34412.58%66.98%
Johannes Weiner32011.70%55.81%
Hugh Dickins2539.25%66.98%
Lukas Czerner2017.35%22.33%
Nicholas Piggin1395.08%66.98%
Kirill A. Shutemov1083.95%44.65%
Hans Reiser772.82%11.16%
David Howells682.49%33.49%
Trond Myklebust672.45%22.33%
Fengguang Wu632.30%11.16%
Zach Brown622.27%11.16%
Andi Kleen552.01%11.16%
Christoph Hellwig321.17%11.16%
Hisashi Hifumi250.91%22.33%
Dan Magenheimer230.84%22.33%
MinChan Kim230.84%44.65%
Greg Thelen170.62%11.16%
Linus Torvalds170.62%11.16%
Arnaldo Carvalho de Melo160.59%11.16%
Stephen C. Tweedie150.55%11.16%
Ross Zwisler130.48%11.16%
Oleg Drokin110.40%11.16%
Neil Brown80.29%11.16%
Jens Axboe40.15%11.16%
Björn Steinbrink40.15%11.16%
Tejun Heo40.15%22.33%
Nate Diller30.11%11.16%
Alexey Dobriyan30.11%11.16%
Fabian Frederick30.11%11.16%
Rik Van Riel30.11%11.16%
Mike Waychison20.07%11.16%
Anton Altaparmakov10.04%11.16%
Anderson Briglia10.04%11.16%
Konstantin Khlebnikov10.04%11.16%
Peng Tao10.04%11.16%
Hirofumi Ogawa10.04%11.16%
David Shaohua Li10.04%11.16%
Francois Cami10.04%11.16%
Paul Gortmaker10.04%11.16%
Total2735100.00%86100.00%
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