The patch allows fuse_req to refer to array of iovec-s describing layout of user-data over req->pages. fuse_copy_pages() is re-worked to support both cased: former layout where pages[] corresponded to <buf, len> and newer one where pages[] corresponds to iovec[].
Signed-off-by: Maxim Patlasov <[email protected]> --- fs/fuse/dev.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++--- fs/fuse/fuse_i.h | 12 ++++++++++-- 2 files changed, 59 insertions(+), 5 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 7df2b5e..cdae525 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -850,9 +850,9 @@ static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep, return 0; } -/* Copy pages in the request to/from userspace buffer */ -static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, - int zeroing) +/* Start from addr(pages[0]) + page_offset. No holes in the middle. */ +static int fuse_copy_pages_for_buf(struct fuse_copy_state *cs, unsigned nbytes, + int zeroing) { unsigned i; struct fuse_req *req = cs->req; @@ -874,6 +874,52 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, return 0; } +/* Take iov_offset as offset in iovec[0]. Iterate based on iovec[].iov_len */ +static int fuse_copy_pages_for_iovec(struct fuse_copy_state *cs, + unsigned nbytes, int zeroing) +{ + unsigned i; + struct fuse_req *req = cs->req; + const struct iovec *iov = req->iovec; + unsigned iov_offset = req->iov_offset; + + for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) { + int err; + unsigned long user_addr = (unsigned long)iov->iov_base + + iov_offset; + unsigned offset = user_addr & ~PAGE_MASK; + unsigned count = min_t(size_t, PAGE_SIZE - offset, + iov->iov_len - iov_offset); + count = min(nbytes, count); + + err = fuse_copy_page(cs, &req->pages[i], offset, count, + zeroing); + if (err) + return err; + + nbytes -= count; + + if (count < iov->iov_len - iov_offset) { + iov_offset += count; + } else { + iov++; + iov_offset = 0; + } + } + + return 0; +} + +/* Copy pages in the request to/from userspace buffer */ +static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes, + int zeroing) +{ + if (cs->req->iovec) + return fuse_copy_pages_for_iovec(cs, nbytes, zeroing); + else + return fuse_copy_pages_for_buf(cs, nbytes, zeroing); +} + /* Copy a single argument in the request to/from userspace buffer */ static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size) { diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 771fb63..255b7cd 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -296,8 +296,16 @@ struct fuse_req { /** number of pages in vector */ unsigned num_pages; - /** offset of data on first page */ - unsigned page_offset; + /** If set, it describes layout of user-data in pages[] */ + const struct iovec *iovec; + + union { + /** offset of data on first page */ + unsigned page_offset; + + /** or in first iovec */ + unsigned iov_offset; + }; /** File used in the request (or NULL) */ struct fuse_file *ff; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
