libfs.c (5c34202b8bf942da411b6599668a76b07449bbfd) libfs.c (afddba49d18f346e5cc2938b6ed7c512db18ca68)
1/*
2 * fs/libfs.c
3 * Library for filesystems writers.
4 */
5
6#include <linux/module.h>
7#include <linux/pagemap.h>
8#include <linux/mount.h>

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346 memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
347 flush_dcache_page(page);
348 kunmap_atomic(kaddr, KM_USER0);
349 }
350 }
351 return 0;
352}
353
1/*
2 * fs/libfs.c
3 * Library for filesystems writers.
4 */
5
6#include <linux/module.h>
7#include <linux/pagemap.h>
8#include <linux/mount.h>

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346 memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
347 flush_dcache_page(page);
348 kunmap_atomic(kaddr, KM_USER0);
349 }
350 }
351 return 0;
352}
353
354int simple_write_begin(struct file *file, struct address_space *mapping,
355 loff_t pos, unsigned len, unsigned flags,
356 struct page **pagep, void **fsdata)
357{
358 struct page *page;
359 pgoff_t index;
360 unsigned from;
361
362 index = pos >> PAGE_CACHE_SHIFT;
363 from = pos & (PAGE_CACHE_SIZE - 1);
364
365 page = __grab_cache_page(mapping, index);
366 if (!page)
367 return -ENOMEM;
368
369 *pagep = page;
370
371 return simple_prepare_write(file, page, from, from+len);
372}
373
354int simple_commit_write(struct file *file, struct page *page,
355 unsigned from, unsigned to)
356{
357 struct inode *inode = page->mapping->host;
358 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
359
360 if (!PageUptodate(page))
361 SetPageUptodate(page);
362 /*
363 * No need to use i_size_read() here, the i_size
364 * cannot change under us because we hold the i_mutex.
365 */
366 if (pos > inode->i_size)
367 i_size_write(inode, pos);
368 set_page_dirty(page);
369 return 0;
370}
371
374int simple_commit_write(struct file *file, struct page *page,
375 unsigned from, unsigned to)
376{
377 struct inode *inode = page->mapping->host;
378 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
379
380 if (!PageUptodate(page))
381 SetPageUptodate(page);
382 /*
383 * No need to use i_size_read() here, the i_size
384 * cannot change under us because we hold the i_mutex.
385 */
386 if (pos > inode->i_size)
387 i_size_write(inode, pos);
388 set_page_dirty(page);
389 return 0;
390}
391
392int simple_write_end(struct file *file, struct address_space *mapping,
393 loff_t pos, unsigned len, unsigned copied,
394 struct page *page, void *fsdata)
395{
396 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
397
398 /* zero the stale part of the page if we did a short copy */
399 if (copied < len) {
400 void *kaddr = kmap_atomic(page, KM_USER0);
401 memset(kaddr + from + copied, 0, len - copied);
402 flush_dcache_page(page);
403 kunmap_atomic(kaddr, KM_USER0);
404 }
405
406 simple_commit_write(file, page, from, from+copied);
407
408 unlock_page(page);
409 page_cache_release(page);
410
411 return copied;
412}
413
372/*
373 * the inodes created here are not hashed. If you use iunique to generate
374 * unique inode values later for this filesystem, then you must take care
375 * to pass it an appropriate max_reserved value to avoid collisions.
376 */
377int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files)
378{
379 struct inode *inode;

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637}
638
639EXPORT_SYMBOL(dcache_dir_close);
640EXPORT_SYMBOL(dcache_dir_lseek);
641EXPORT_SYMBOL(dcache_dir_open);
642EXPORT_SYMBOL(dcache_readdir);
643EXPORT_SYMBOL(generic_read_dir);
644EXPORT_SYMBOL(get_sb_pseudo);
414/*
415 * the inodes created here are not hashed. If you use iunique to generate
416 * unique inode values later for this filesystem, then you must take care
417 * to pass it an appropriate max_reserved value to avoid collisions.
418 */
419int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files)
420{
421 struct inode *inode;

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679}
680
681EXPORT_SYMBOL(dcache_dir_close);
682EXPORT_SYMBOL(dcache_dir_lseek);
683EXPORT_SYMBOL(dcache_dir_open);
684EXPORT_SYMBOL(dcache_readdir);
685EXPORT_SYMBOL(generic_read_dir);
686EXPORT_SYMBOL(get_sb_pseudo);
687EXPORT_SYMBOL(simple_write_begin);
688EXPORT_SYMBOL(simple_write_end);
645EXPORT_SYMBOL(simple_commit_write);
646EXPORT_SYMBOL(simple_dir_inode_operations);
647EXPORT_SYMBOL(simple_dir_operations);
648EXPORT_SYMBOL(simple_empty);
649EXPORT_SYMBOL(d_alloc_name);
650EXPORT_SYMBOL(simple_fill_super);
651EXPORT_SYMBOL(simple_getattr);
652EXPORT_SYMBOL(simple_link);

--- 18 unchanged lines hidden --- 		689EXPORT_SYMBOL(simple_commit_write);
690EXPORT_SYMBOL(simple_dir_inode_operations);
691EXPORT_SYMBOL(simple_dir_operations);
692EXPORT_SYMBOL(simple_empty);
693EXPORT_SYMBOL(d_alloc_name);
694EXPORT_SYMBOL(simple_fill_super);
695EXPORT_SYMBOL(simple_getattr);
696EXPORT_SYMBOL(simple_link);

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