diff options
Diffstat (limited to 'fs/libfs.c')
| -rw-r--r-- | fs/libfs.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 5294de1f40c..f2b32d3a909 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -351,6 +351,26 @@ int simple_prepare_write(struct file *file, struct page *page, return 0; } +int simple_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) +{ + struct page *page; + pgoff_t index; + unsigned from; + + index = pos >> PAGE_CACHE_SHIFT; + from = pos & (PAGE_CACHE_SIZE - 1); + + page = __grab_cache_page(mapping, index); + if (!page) + return -ENOMEM; + + *pagep = page; + + return simple_prepare_write(file, page, from, from+len); +} + int simple_commit_write(struct file *file, struct page *page, unsigned from, unsigned to) { @@ -369,6 +389,28 @@ int simple_commit_write(struct file *file, struct page *page, return 0; } +int simple_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + unsigned from = pos & (PAGE_CACHE_SIZE - 1); + + /* zero the stale part of the page if we did a short copy */ + if (copied < len) { + void *kaddr = kmap_atomic(page, KM_USER0); + memset(kaddr + from + copied, 0, len - copied); + flush_dcache_page(page); + kunmap_atomic(kaddr, KM_USER0); + } + + simple_commit_write(file, page, from, from+copied); + + unlock_page(page); + page_cache_release(page); + + return copied; +} + /* * the inodes created here are not hashed. If you use iunique to generate * unique inode values later for this filesystem, then you must take care @@ -642,6 +684,8 @@ EXPORT_SYMBOL(dcache_dir_open); EXPORT_SYMBOL(dcache_readdir); EXPORT_SYMBOL(generic_read_dir); EXPORT_SYMBOL(get_sb_pseudo); +EXPORT_SYMBOL(simple_write_begin); +EXPORT_SYMBOL(simple_write_end); EXPORT_SYMBOL(simple_commit_write); EXPORT_SYMBOL(simple_dir_inode_operations); EXPORT_SYMBOL(simple_dir_operations); |