On 12/30/2009 05:40 PM, Boaz Harrosh wrote: > > * simple_commit_write was only called by simple_write_end. > Open coding it makes it tiny bit less heavy on the arithmetic and > much more readable. > > * While at it use zero_user() for clearing a partial page. > * While at it add a docbook comment for simple_write_end. > > Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx> Al Hi When looking in fs/libfs.c I can see that also simple_prepare_write() is only used once, locally, but is exported nonetheless. Has its time expired by now? [And what does EXPORT_UNUSED_SYMBOL() means ?]. This patch was triggered by this fix: http://marc.info/?l=linux-fsdevel&m=126193226815716&w=2 Thanks Boaz > --- > fs/libfs.c | 59 +++++++++++++++++++++++++++++++++++------------------------ > 1 files changed, 35 insertions(+), 24 deletions(-) > > diff --git a/fs/libfs.c b/fs/libfs.c > index 6e8d17e..4afb933 100644 > --- a/fs/libfs.c > +++ b/fs/libfs.c > @@ -370,40 +370,51 @@ int simple_write_begin(struct file *file, struct address_space *mapping, > return simple_prepare_write(file, page, from, from+len); > } > > -static int simple_commit_write(struct file *file, struct page *page, > - unsigned from, unsigned to) > -{ > - struct inode *inode = page->mapping->host; > - loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; > - > - if (!PageUptodate(page)) > - SetPageUptodate(page); > - /* > - * No need to use i_size_read() here, the i_size > - * cannot change under us because we hold the i_mutex. > - */ > - if (pos > inode->i_size) > - i_size_write(inode, pos); > - set_page_dirty(page); > - return 0; > -} > - > +/** > + * simple_write_end - .write_end helper for none block-device FSs > + * @available: See .write_end of address_space_operations > + * @file: " > + * @mapping: " > + * @pos: " > + * @len: " > + * @copied: " > + * @page: " > + * @fsdata: " > + * > + * simple_write_end does the minimum needed for updating a page after writing is > + * done. It has the same API signature as the .write_end of > + * address_space_operations vector. So it can just be set onto .write_end for > + * FSs that don't need any other processing. i_mutex is assumed to be held. > + * Block based filesystems should use generic_write_end(). > + * NOTE: Even though i_size might get updated by this function mark_inode_dirty > + * is not called, so a filesystem that actually does store data in .write_inode > + * should extend on what's done here with a call to mark_inode_dirty() in the > + * case that i_size has changed. > + **/ > 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); > + struct inode *inode = page->mapping->host; > + loff_t last_pos = pos + copied; > > /* 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); > + unsigned from = pos & (PAGE_CACHE_SIZE - 1); > + > + zero_user(page, from + copied, len - copied); > } > > - simple_commit_write(file, page, from, from+copied); > + if (!PageUptodate(page)) > + SetPageUptodate(page); > + /* > + * No need to use i_size_read() here, the i_size > + * cannot change under us because we hold the i_mutex. > + */ > + if (last_pos > inode->i_size) > + i_size_write(inode, last_pos); > > + set_page_dirty(page); > unlock_page(page); > page_cache_release(page); > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
