From b98d023a24496bf7d538c549e5426b1173c6f55d Mon Sep 17 00:00:00 2001 From: Maxim Patlasov Date: Fri, 26 Oct 2012 19:50:15 +0400 Subject: fuse: pass iov[] to fuse_get_user_pages() The patch makes preliminary work for the next patch optimizing scatter-gather direct IO. The idea is to allow fuse_get_user_pages() to pack as many iov-s to each fuse request as possible. So, here we only rework all related call-paths to carry iov[] from fuse_direct_IO() to fuse_get_user_pages(). Signed-off-by: Maxim Patlasov Signed-off-by: Miklos Szeredi --- fs/fuse/file.c | 103 +++++++++++++++++++++++++++------------------------------ 1 file changed, 49 insertions(+), 54 deletions(-) (limited to 'fs/fuse') diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 3384a200b3ee..542ad97b103a 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1056,14 +1056,18 @@ static inline void fuse_page_descs_length_init(struct fuse_req *req) req->page_descs[i].offset; } -static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, +static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, size_t *nbytesp, int write) { size_t nbytes = *nbytesp; - unsigned long user_addr = (unsigned long) buf; - unsigned offset = user_addr & ~PAGE_MASK; + size_t frag_size = min(iov_iter_single_seg_count(ii), nbytes); + unsigned long user_addr; + unsigned offset; int npages; + user_addr = (unsigned long)ii->iov->iov_base + ii->iov_offset; + offset = user_addr & ~PAGE_MASK; + /* Special case for kernel I/O: can copy directly into the buffer */ if (segment_eq(get_fs(), KERNEL_DS)) { if (write) @@ -1071,10 +1075,12 @@ static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, else req->out.args[0].value = (void *) user_addr; + iov_iter_advance(ii, frag_size); + *nbytesp = frag_size; return 0; } - nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); + nbytes = min_t(size_t, frag_size, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ); npages = get_user_pages_fast(user_addr, npages, !write, req->pages); @@ -1092,17 +1098,19 @@ static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, nbytes = (req->num_pages << PAGE_SHIFT) - req->page_descs[0].offset; - if (*nbytesp < nbytes) + if (frag_size < nbytes) req->page_descs[req->num_pages - 1].length -= - nbytes - *nbytesp; + nbytes - frag_size; - *nbytesp = min(*nbytesp, nbytes); + *nbytesp = min(frag_size, nbytes); + iov_iter_advance(ii, *nbytesp); return 0; } -ssize_t fuse_direct_io(struct file *file, const char __user *buf, - size_t count, loff_t *ppos, int write) +static ssize_t __fuse_direct_io(struct file *file, const struct iovec *iov, + unsigned long nr_segs, size_t count, + loff_t *ppos, int write) { struct fuse_file *ff = file->private_data; struct fuse_conn *fc = ff->fc; @@ -1110,6 +1118,9 @@ ssize_t fuse_direct_io(struct file *file, const char __user *buf, loff_t pos = *ppos; ssize_t res = 0; struct fuse_req *req; + struct iov_iter ii; + + iov_iter_init(&ii, iov, nr_segs, count, 0); req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ); if (IS_ERR(req)) @@ -1119,7 +1130,7 @@ ssize_t fuse_direct_io(struct file *file, const char __user *buf, size_t nres; fl_owner_t owner = current->files; size_t nbytes = min(count, nmax); - int err = fuse_get_user_pages(req, buf, &nbytes, write); + int err = fuse_get_user_pages(req, &ii, &nbytes, write); if (err) { res = err; break; @@ -1142,7 +1153,6 @@ ssize_t fuse_direct_io(struct file *file, const char __user *buf, count -= nres; res += nres; pos += nres; - buf += nres; if (nres != nbytes) break; if (count) { @@ -1159,10 +1169,17 @@ ssize_t fuse_direct_io(struct file *file, const char __user *buf, return res; } + +ssize_t fuse_direct_io(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, int write) +{ + struct iovec iov = { .iov_base = (void *)buf, .iov_len = count }; + return __fuse_direct_io(file, &iov, 1, count, ppos, write); +} EXPORT_SYMBOL_GPL(fuse_direct_io); -static ssize_t fuse_direct_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) +static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov, + unsigned long nr_segs, loff_t *ppos) { ssize_t res; struct inode *inode = file->f_path.dentry->d_inode; @@ -1170,22 +1187,31 @@ static ssize_t fuse_direct_read(struct file *file, char __user *buf, if (is_bad_inode(inode)) return -EIO; - res = fuse_direct_io(file, buf, count, ppos, 0); + res = __fuse_direct_io(file, iov, nr_segs, iov_length(iov, nr_segs), + ppos, 0); fuse_invalidate_attr(inode); return res; } -static ssize_t __fuse_direct_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) +static ssize_t fuse_direct_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct iovec iov = { .iov_base = (void *)buf, .iov_len = count }; + return __fuse_direct_read(file, &iov, 1, ppos); +} + +static ssize_t __fuse_direct_write(struct file *file, const struct iovec *iov, + unsigned long nr_segs, loff_t *ppos) { struct inode *inode = file->f_path.dentry->d_inode; + size_t count = iov_length(iov, nr_segs); ssize_t res; res = generic_write_checks(file, ppos, &count, 0); if (!res) { - res = fuse_direct_io(file, buf, count, ppos, 1); + res = __fuse_direct_io(file, iov, nr_segs, count, ppos, 1); if (res > 0) fuse_write_update_size(inode, *ppos); } @@ -1198,6 +1224,7 @@ static ssize_t __fuse_direct_write(struct file *file, const char __user *buf, static ssize_t fuse_direct_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { + struct iovec iov = { .iov_base = (void *)buf, .iov_len = count }; struct inode *inode = file->f_path.dentry->d_inode; ssize_t res; @@ -1206,7 +1233,7 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf, /* Don't allow parallel writes to the same file */ mutex_lock(&inode->i_mutex); - res = __fuse_direct_write(file, buf, count, ppos); + res = __fuse_direct_write(file, &iov, 1, ppos); mutex_unlock(&inode->i_mutex); return res; @@ -2167,41 +2194,6 @@ int fuse_notify_poll_wakeup(struct fuse_conn *fc, return 0; } -static ssize_t fuse_loop_dio(struct file *filp, const struct iovec *iov, - unsigned long nr_segs, loff_t *ppos, int rw) -{ - const struct iovec *vector = iov; - ssize_t ret = 0; - - while (nr_segs > 0) { - void __user *base; - size_t len; - ssize_t nr; - - base = vector->iov_base; - len = vector->iov_len; - vector++; - nr_segs--; - - if (rw == WRITE) - nr = __fuse_direct_write(filp, base, len, ppos); - else - nr = fuse_direct_read(filp, base, len, ppos); - - if (nr < 0) { - if (!ret) - ret = nr; - break; - } - ret += nr; - if (nr != len) - break; - } - - return ret; -} - - static ssize_t fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) @@ -2213,7 +2205,10 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, file = iocb->ki_filp; pos = offset; - ret = fuse_loop_dio(file, iov, nr_segs, &pos, rw); + if (rw == WRITE) + ret = __fuse_direct_write(file, iov, nr_segs, &pos); + else + ret = __fuse_direct_read(file, iov, nr_segs, &pos); return ret; } -- cgit v1.2.3