diff options
| -rw-r--r-- | fs/cifs/file.c | 84 |
1 files changed, 50 insertions, 34 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index ff4a9c3fe42..f96f61c849f 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2423,11 +2423,53 @@ 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 *num_pages) +{ + size_t save_len, copied, bytes, cur_len = *len; + unsigned long i, nr_pages = *num_pages; + + 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. + */ + *num_pages = i + 1; + return 0; +} + 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; + unsigned long nr_pages, num_pages, i; + size_t len, cur_len; ssize_t total_written = 0; loff_t offset; struct cifsFileInfo *open_file; @@ -2464,8 +2506,6 @@ 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); @@ -2480,44 +2520,20 @@ 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) { + num_pages = nr_pages; + rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_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. + * Bring nr_pages down to the number of pages we actually used, + * and free any pages that we didn't use. */ - for ( ; nr_pages > i + 1; nr_pages--) + for ( ; nr_pages > num_pages; nr_pages--) put_page(wdata->pages[nr_pages - 1]); wdata->sync_mode = WB_SYNC_ALL; |