Messages in this thread Patch in this message | | | Date | Wed, 04 Jan 2006 14:15:35 +0100 | From | Miklos Szeredi <> | Subject | [PATCH 5/6] fuse: ensure progress in read and write |
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In direct_io mode, send at least one page per reqest. Previously it was possible that reqests with zero data were sent, and hence the read/write didn't make any progress, resulting in an infinite (though interruptible) loop.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> ---
Index: linux/fs/fuse/file.c =================================================================== --- linux.orig/fs/fuse/file.c 2006-01-04 12:37:52.000000000 +0100 +++ linux/fs/fuse/file.c 2006-01-04 12:37:56.000000000 +0100 @@ -475,7 +475,7 @@ static int fuse_get_user_pages(struct fu nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; - npages = min(npages, FUSE_MAX_PAGES_PER_REQ); + npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ); down_read(¤t->mm->mmap_sem); npages = get_user_pages(current, current->mm, user_addr, npages, write, 0, req->pages, NULL); @@ -506,7 +506,6 @@ static ssize_t fuse_direct_io(struct fil return -EINTR; while (count) { - size_t tmp; size_t nres; size_t nbytes = min(count, nmax); int err = fuse_get_user_pages(req, buf, nbytes, !write); @@ -514,8 +513,8 @@ static ssize_t fuse_direct_io(struct fil res = err; break; } - tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset; - nbytes = min(nbytes, tmp); + nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset; + nbytes = min(count, nbytes); if (write) nres = fuse_send_write(req, file, inode, pos, nbytes); else -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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