On Tue, Aug 14, 2018 at 11:17 PM, Constantine Shulyupin <const@xxxxxxxxxxxxx> wrote: > Replace FUSE_MAX_PAGES_PER_REQ with the configurable > mount parameter max_pages to improve performance. > > Old RFC with detailed description of the problem and > many fixes by Mitsuo Hayasaka (mitsuo.hayasaka.hu@xxxxxxxxxxx): > - https://lkml.org/lkml/2012/7/5/136 It would be nice to have some performance numbers before/after the patch. > > Changes in v3: > - used clamp_val > - split documentation change > - split EXPORT_SYMBOL(pipe_max_size) > > Changes in v2: > - add limitation by pipe_max_size, which was requested in > https://lkml.org/lkml/2012/7/12/32 > > Changes in v1: https://lkml.org/lkml/2017/8/6/194 > - replace FUSE_MAX_PAGES_PER_REQ with > FUSE_DEFAULT_MAX_PAGES_PER_REQ and > fc->max_pages > - add mount option max_pages > > Signed-off-by: Constantine Shulyupin <const@xxxxxxxxxxxxx> > --- > fs/fuse/dev.c | 4 ++-- > fs/fuse/file.c | 54 ++++++++++++++++++++++++------------------------ > fs/fuse/fuse_i.h | 5 ++++- > fs/fuse/inode.c | 14 +++++++++++++ > 4 files changed, 47 insertions(+), 30 deletions(-) > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c > index 11ea2c4a38ab..b324ffc2d82a 100644 > --- a/fs/fuse/dev.c > +++ b/fs/fuse/dev.c > @@ -1663,7 +1663,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, > unsigned int num; > unsigned int offset; > size_t total_len = 0; > - int num_pages; > + unsigned num_pages; > > offset = outarg->offset & ~PAGE_MASK; > file_size = i_size_read(inode); > @@ -1675,7 +1675,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, > num = file_size - outarg->offset; > > num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; > - num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ); > + num_pages = min(num_pages, fc->max_pages); > > req = fuse_get_req(fc, num_pages); > if (IS_ERR(req)) > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > index fe8d84eb714a..e0924e46ef24 100644 > --- a/fs/fuse/file.c > +++ b/fs/fuse/file.c > @@ -847,11 +847,11 @@ static int fuse_readpages_fill(void *_data, struct page *page) > fuse_wait_on_page_writeback(inode, page->index); > > if (req->num_pages && > - (req->num_pages == FUSE_MAX_PAGES_PER_REQ || > + (req->num_pages == fc->max_pages || > (req->num_pages + 1) * PAGE_SIZE > fc->max_read || > req->pages[req->num_pages - 1]->index + 1 != page->index)) { > int nr_alloc = min_t(unsigned, data->nr_pages, > - FUSE_MAX_PAGES_PER_REQ); > + fc->max_pages); > fuse_send_readpages(req, data->file); > if (fc->async_read) > req = fuse_get_req_for_background(fc, nr_alloc); > @@ -886,7 +886,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping, > struct fuse_conn *fc = get_fuse_conn(inode); > struct fuse_fill_data data; > int err; > - int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ); > + int nr_alloc = min_t(unsigned, nr_pages, fc->max_pages); > > err = -EIO; > if (is_bad_inode(inode)) > @@ -1101,12 +1101,12 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req, > return count > 0 ? count : err; > } > > -static inline unsigned fuse_wr_pages(loff_t pos, size_t len) > +static inline unsigned fuse_wr_pages(loff_t pos, size_t len, unsigned max_pages) > { > return min_t(unsigned, > ((pos + len - 1) >> PAGE_SHIFT) - > (pos >> PAGE_SHIFT) + 1, > - FUSE_MAX_PAGES_PER_REQ); > + max_pages); > } > > static ssize_t fuse_perform_write(struct kiocb *iocb, > @@ -1128,7 +1128,8 @@ static ssize_t fuse_perform_write(struct kiocb *iocb, > do { > struct fuse_req *req; > ssize_t count; > - unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii)); > + unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii), > + fc->max_pages); > > req = fuse_get_req(fc, nr_pages); > if (IS_ERR(req)) { > @@ -1318,11 +1319,6 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, > return ret < 0 ? ret : 0; > } > > -static inline int fuse_iter_npages(const struct iov_iter *ii_p) > -{ > - return iov_iter_npages(ii_p, FUSE_MAX_PAGES_PER_REQ); > -} > - > ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, > loff_t *ppos, int flags) > { > @@ -1342,9 +1338,10 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, > int err = 0; > > if (io->async) > - req = fuse_get_req_for_background(fc, fuse_iter_npages(iter)); > + req = fuse_get_req_for_background(fc, iov_iter_npages(iter, > + fc->max_pages)); > else > - req = fuse_get_req(fc, fuse_iter_npages(iter)); > + req = fuse_get_req(fc, iov_iter_npages(iter, fc->max_pages)); > if (IS_ERR(req)) > return PTR_ERR(req); > > @@ -1389,9 +1386,10 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, > fuse_put_request(fc, req); > if (io->async) > req = fuse_get_req_for_background(fc, > - fuse_iter_npages(iter)); > + iov_iter_npages(iter, fc->max_pages)); > else > - req = fuse_get_req(fc, fuse_iter_npages(iter)); > + req = fuse_get_req(fc, iov_iter_npages(iter, > + fc->max_pages)); > if (IS_ERR(req)) > break; > } > @@ -1818,7 +1816,7 @@ static int fuse_writepages_fill(struct page *page, > is_writeback = fuse_page_is_writeback(inode, page->index); > > if (req && req->num_pages && > - (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ || > + (is_writeback || req->num_pages == fc->max_pages || > (req->num_pages + 1) * PAGE_SIZE > fc->max_write || > data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) { > fuse_writepages_send(data); > @@ -1846,7 +1844,7 @@ static int fuse_writepages_fill(struct page *page, > struct fuse_inode *fi = get_fuse_inode(inode); > > err = -ENOMEM; > - req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ); > + req = fuse_request_alloc_nofs(fc->max_pages); > if (!req) { > __free_page(tmp_page); > goto out_unlock; > @@ -1903,6 +1901,7 @@ static int fuse_writepages(struct address_space *mapping, > struct writeback_control *wbc) > { > struct inode *inode = mapping->host; > + struct fuse_conn *fc = get_fuse_conn(inode); > struct fuse_fill_wb_data data; > int err; > > @@ -1915,7 +1914,7 @@ static int fuse_writepages(struct address_space *mapping, > data.ff = NULL; > > err = -ENOMEM; > - data.orig_pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, > + data.orig_pages = kcalloc(fc->max_pages, > sizeof(struct page *), > GFP_NOFS); > if (!data.orig_pages) > @@ -2386,10 +2385,11 @@ static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, > } > > /* Make sure iov_length() won't overflow */ > -static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count) > +static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov, > + size_t count) > { > size_t n; > - u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT; > + u32 max = fc->max_pages << PAGE_SHIFT; > > for (n = 0; n < count; n++, iov++) { > if (iov->iov_len > (size_t) max) > @@ -2513,7 +2513,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, > BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); > > err = -ENOMEM; > - pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL); > + pages = kcalloc(fc->max_pages, sizeof(pages[0]), GFP_KERNEL); > iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); > if (!pages || !iov_page) > goto out; > @@ -2552,7 +2552,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, > > /* make sure there are enough buffer pages and init request with them */ > err = -ENOMEM; > - if (max_pages > FUSE_MAX_PAGES_PER_REQ) > + if (max_pages > fc->max_pages) > goto out; > while (num_pages < max_pages) { > pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); > @@ -2639,11 +2639,11 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, > in_iov = iov_page; > out_iov = in_iov + in_iovs; > > - err = fuse_verify_ioctl_iov(in_iov, in_iovs); > + err = fuse_verify_ioctl_iov(fc, in_iov, in_iovs); > if (err) > goto out; > > - err = fuse_verify_ioctl_iov(out_iov, out_iovs); > + err = fuse_verify_ioctl_iov(fc, out_iov, out_iovs); > if (err) > goto out; > > @@ -2834,9 +2834,9 @@ static void fuse_do_truncate(struct file *file) > fuse_do_setattr(file_dentry(file), &attr, file); > } > > -static inline loff_t fuse_round_up(loff_t off) > +static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off) > { > - return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); > + return round_up(off, fc->max_pages << PAGE_SHIFT); > } > > static ssize_t > @@ -2865,7 +2865,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) { > if (offset >= i_size) > return 0; > - iov_iter_truncate(iter, fuse_round_up(i_size - offset)); > + iov_iter_truncate(iter, fuse_round_up(ff->fc, i_size - offset)); > count = iov_iter_count(iter); > } > > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h > index f78e9614bb5f..7556301cb493 100644 > --- a/fs/fuse/fuse_i.h > +++ b/fs/fuse/fuse_i.h > @@ -29,7 +29,7 @@ > #include <linux/user_namespace.h> > > /** Max number of pages that can be used in a single read request */ > -#define FUSE_MAX_PAGES_PER_REQ 32 > +#define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32 > > /** Bias for fi->writectr, meaning new writepages must not be sent */ > #define FUSE_NOWRITE INT_MIN > @@ -476,6 +476,9 @@ struct fuse_conn { > /** Maximum write size */ > unsigned max_write; > > + /** Maxmum number of pages that can be used in a single request */ > + unsigned max_pages; > + > /** Input queue */ > struct fuse_iqueue iq; > > diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c > index db9e60b7eb69..aed77c77cccc 100644 > --- a/fs/fuse/inode.c > +++ b/fs/fuse/inode.c > @@ -22,6 +22,7 @@ > #include <linux/exportfs.h> > #include <linux/posix_acl.h> > #include <linux/pid_namespace.h> > +#include <linux/pipe_fs_i.h> > > MODULE_AUTHOR("Miklos Szeredi <miklos@xxxxxxxxxx>"); > MODULE_DESCRIPTION("Filesystem in Userspace"); > @@ -71,6 +72,7 @@ struct fuse_mount_data { > unsigned default_permissions:1; > unsigned allow_other:1; > unsigned max_read; > + unsigned max_pages; > unsigned blksize; > }; > > @@ -453,6 +455,7 @@ enum { > OPT_DEFAULT_PERMISSIONS, > OPT_ALLOW_OTHER, > OPT_MAX_READ, > + OPT_MAX_PAGES, > OPT_BLKSIZE, > OPT_ERR > }; > @@ -465,6 +468,7 @@ static const match_table_t tokens = { > {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, > {OPT_ALLOW_OTHER, "allow_other"}, > {OPT_MAX_READ, "max_read=%u"}, > + {OPT_MAX_PAGES, "max_pages=%u"}, > {OPT_BLKSIZE, "blksize=%u"}, > {OPT_ERR, NULL} Any reason why you used a mount option instead of negotiating with the INIT message? > }; > @@ -546,6 +550,12 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev, > d->max_read = value; > break; > > + case OPT_MAX_PAGES: > + if (match_int(&args[0], &value)) > + return 0; > + d->max_pages = value; > + break; > + > case OPT_BLKSIZE: > if (!is_bdev || match_int(&args[0], &value)) > return 0; > @@ -577,6 +587,8 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root) > seq_puts(m, ",allow_other"); > if (fc->max_read != ~0) > seq_printf(m, ",max_read=%u", fc->max_read); > + if (fc->max_pages != FUSE_DEFAULT_MAX_PAGES_PER_REQ) > + seq_printf(m, ",max_pages=%u", fc->max_pages); > if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) > seq_printf(m, ",blksize=%lu", sb->s_blocksize); > return 0; > @@ -1141,6 +1153,8 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) > fc->user_id = d.user_id; > fc->group_id = d.group_id; > fc->max_read = max_t(unsigned, 4096, d.max_read); > + fc->max_pages = clamp_val(d.max_pages, FUSE_DEFAULT_MAX_PAGES_PER_REQ, > + pipe_max_size >> PAGE_SHIFT); > > /* Used by get_root_inode() */ > sb->s_fs_info = fc; > -- > 2.17.1 >
