From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shirish Pargaonkar Subject: Re: [PATCH v2 07/16] CIFS: Separate filling pages from iovec write Date: Sun, 20 Jul 2014 22:59:35 -0500 Message-ID: References: <1403863073-19526-1-git-send-email-pshilovsky@samba.org> <1403863073-19526-8-git-send-email-pshilovsky@samba.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-cifs To: Pavel Shilovsky Return-path: In-Reply-To: <1403863073-19526-8-git-send-email-pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Like put_page() for rc = 0 unused pages was moved to wdata_fill_from_iovec(), probably move put_page in case of -EFAULT also to wdata_fill_from_iovec()? So just kfree and break if(rc)? Also, wdata_fill_from_iovec() does not need rc, it can just return 0 in case of no error? On Fri, Jun 27, 2014 at 4:57 AM, Pavel Shilovsky wrote: > Signed-off-by: Pavel Shilovsky > --- > fs/cifs/file.c | 85 +++++++++++++++++++++++++++++++++------------------------- > 1 file changed, 48 insertions(+), 37 deletions(-) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 21f9be0..e2a735a 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -2423,11 +2423,56 @@ cifs_uncached_retry_writev(struct cifs_writedata *wdata) > return rc; > } > > +static int > +wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from, > + size_t *len, unsigned long nr_pages) > +{ > + int rc = 0; > + size_t save_len, copied, bytes, cur_len = *len; > + unsigned long i; > + > + save_len = cur_len; > + for (i = 0; i < nr_pages; i++) { > + bytes = min_t(const size_t, cur_len, PAGE_SIZE); > + copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from); > + cur_len -= copied; > + /* > + * If we didn't copy as much as we expected, then that > + * may mean we trod into an unmapped area. Stop copying > + * at that point. On the next pass through the big > + * loop, we'll likely end up getting a zero-length > + * write and bailing out of it. > + */ > + if (copied < bytes) > + break; > + } > + cur_len = save_len - cur_len; > + *len = cur_len; > + > + /* > + * If we have no data to send, then that probably means that > + * the copy above failed altogether. That's most likely because > + * the address in the iovec was bogus. Return -EFAULT and let > + * the caller free anything we allocated and bail out. > + */ > + if (!cur_len) > + return -EFAULT; > + > + /* > + * i + 1 now represents the number of pages we actually used in > + * the copy phase above. Bring nr_pages down to that, and free > + * any pages that we didn't use. > + */ > + for ( ; nr_pages > i + 1; nr_pages--) > + put_page(wdata->pages[nr_pages - 1]); > + return rc; > +} > + > static ssize_t > cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset) > { > unsigned long nr_pages, i; > - size_t bytes, copied, len, cur_len; > + size_t len, cur_len; > ssize_t total_written = 0; > loff_t offset; > struct cifsFileInfo *open_file; > @@ -2464,8 +2509,6 @@ cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset) > pid = current->tgid; > > do { > - size_t save_len; > - > nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len); > wdata = cifs_writedata_alloc(nr_pages, > cifs_uncached_writev_complete); > @@ -2480,46 +2523,14 @@ cifs_iovec_write(struct file *file, struct iov_iter *from, loff_t *poffset) > break; > } > > - save_len = cur_len; > - for (i = 0; i < nr_pages; i++) { > - bytes = min_t(size_t, cur_len, PAGE_SIZE); > - copied = copy_page_from_iter(wdata->pages[i], 0, bytes, > - from); > - cur_len -= copied; > - /* > - * If we didn't copy as much as we expected, then that > - * may mean we trod into an unmapped area. Stop copying > - * at that point. On the next pass through the big > - * loop, we'll likely end up getting a zero-length > - * write and bailing out of it. > - */ > - if (copied < bytes) > - break; > - } > - cur_len = save_len - cur_len; > - > - /* > - * If we have no data to send, then that probably means that > - * the copy above failed altogether. That's most likely because > - * the address in the iovec was bogus. Set the rc to -EFAULT, > - * free anything we allocated and bail out. > - */ > - if (!cur_len) { > + rc = wdata_fill_from_iovec(wdata, from, &cur_len, nr_pages); > + if (rc) { > for (i = 0; i < nr_pages; i++) > put_page(wdata->pages[i]); > kfree(wdata); > - rc = -EFAULT; > break; > } > > - /* > - * i + 1 now represents the number of pages we actually used in > - * the copy phase above. Bring nr_pages down to that, and free > - * any pages that we didn't use. > - */ > - for ( ; nr_pages > i + 1; nr_pages--) > - put_page(wdata->pages[nr_pages - 1]); > - > wdata->sync_mode = WB_SYNC_ALL; > wdata->nr_pages = nr_pages; > wdata->offset = (__u64)offset; > -- > 1.8.1.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html