diff options
| -rw-r--r-- | fs/fuse/file.c | 133 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 6 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 9 |
3 files changed, 146 insertions, 2 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 86ffb6d..6bc3fb2 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -363,6 +363,118 @@ static int fuse_commit_write(struct file *file, struct page *page, return err; } +static void fuse_release_user_pages(struct fuse_req *req, int write) +{ + unsigned i; + + for (i = 0; i < req->num_pages; i++) { + struct page *page = req->pages[i]; + if (write) + set_page_dirty_lock(page); + put_page(page); + } +} + +static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, + unsigned nbytes, int write) +{ + unsigned long user_addr = (unsigned long) buf; + unsigned offset = user_addr & ~PAGE_MASK; + int npages; + + /* This doesn't work with nfsd */ + if (!current->mm) + return -EPERM; + + 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); + down_read(¤t->mm->mmap_sem); + npages = get_user_pages(current, current->mm, user_addr, npages, write, + 0, req->pages, NULL); + up_read(¤t->mm->mmap_sem); + if (npages < 0) + return npages; + + req->num_pages = npages; + req->page_offset = offset; + return 0; +} + +static ssize_t fuse_direct_io(struct file *file, const char __user *buf, + size_t count, loff_t *ppos, int write) +{ + struct inode *inode = file->f_dentry->d_inode; + struct fuse_conn *fc = get_fuse_conn(inode); + size_t nmax = write ? fc->max_write : fc->max_read; + loff_t pos = *ppos; + ssize_t res = 0; + struct fuse_req *req = fuse_get_request(fc); + if (!req) + return -ERESTARTSYS; + + while (count) { + size_t tmp; + size_t nres; + size_t nbytes = min(count, nmax); + int err = fuse_get_user_pages(req, buf, nbytes, !write); + if (err) { + res = err; + break; + } + tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset; + nbytes = min(nbytes, tmp); + if (write) + nres = fuse_send_write(req, file, inode, pos, nbytes); + else + nres = fuse_send_read(req, file, inode, pos, nbytes); + fuse_release_user_pages(req, !write); + if (req->out.h.error) { + if (!res) + res = req->out.h.error; + break; + } else if (nres > nbytes) { + res = -EIO; + break; + } + count -= nres; + res += nres; + pos += nres; + buf += nres; + if (nres != nbytes) + break; + if (count) + fuse_reset_request(req); + } + fuse_put_request(fc, req); + if (res > 0) { + if (write && pos > i_size_read(inode)) + i_size_write(inode, pos); + *ppos = pos; + } else if (write && (res == -EINTR || res == -EIO)) + fuse_invalidate_attr(inode); + + return res; +} + +static ssize_t fuse_direct_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + return fuse_direct_io(file, buf, count, ppos, 0); +} + +static ssize_t fuse_direct_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct inode *inode = file->f_dentry->d_inode; + ssize_t res; + /* Don't allow parallel writes to the same file */ + down(&inode->i_sem); + res = fuse_direct_io(file, buf, count, ppos, 1); + up(&inode->i_sem); + return res; +} + static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) { if ((vma->vm_flags & VM_SHARED)) { @@ -393,6 +505,17 @@ static struct file_operations fuse_file_operations = { .sendfile = generic_file_sendfile, }; +static struct file_operations fuse_direct_io_file_operations = { + .llseek = generic_file_llseek, + .read = fuse_direct_read, + .write = fuse_direct_write, + .open = fuse_open, + .flush = fuse_flush, + .release = fuse_release, + .fsync = fuse_fsync, + /* no mmap and sendfile */ +}; + static struct address_space_operations fuse_file_aops = { .readpage = fuse_readpage, .prepare_write = fuse_prepare_write, @@ -403,6 +526,12 @@ static struct address_space_operations fuse_file_aops = { void fuse_init_file_inode(struct inode *inode) { - inode->i_fop = &fuse_file_operations; - inode->i_data.a_ops = &fuse_file_aops; + struct fuse_conn *fc = get_fuse_conn(inode); + + if (fc->flags & FUSE_DIRECT_IO) + inode->i_fop = &fuse_direct_io_file_operations; + else { + inode->i_fop = &fuse_file_operations; + inode->i_data.a_ops = &fuse_file_aops; + } } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 3ec2aff..0af1ac6 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -34,6 +34,9 @@ be flushed on open */ #define FUSE_KERNEL_CACHE (1 << 2) +/** Bypass the page cache for read and write operations */ +#define FUSE_DIRECT_IO (1 << 3) + /** FUSE inode */ struct fuse_inode { /** Inode data */ @@ -207,6 +210,9 @@ struct fuse_conn { /** Maximum read size */ unsigned max_read; + /** Maximum write size */ + unsigned max_write; + /** Readers of the connection are waiting on this */ wait_queue_head_t waitq; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 298c1d4..652c9d5 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -258,6 +258,7 @@ enum { OPT_DEFAULT_PERMISSIONS, OPT_ALLOW_OTHER, OPT_KERNEL_CACHE, + OPT_DIRECT_IO, OPT_MAX_READ, OPT_ERR }; @@ -270,6 +271,7 @@ static match_table_t tokens = { {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, {OPT_ALLOW_OTHER, "allow_other"}, {OPT_KERNEL_CACHE, "kernel_cache"}, + {OPT_DIRECT_IO, "direct_io"}, {OPT_MAX_READ, "max_read=%u"}, {OPT_ERR, NULL} }; @@ -329,6 +331,10 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d) d->flags |= FUSE_KERNEL_CACHE; break; + case OPT_DIRECT_IO: + d->flags |= FUSE_DIRECT_IO; + break; + case OPT_MAX_READ: if (match_int(&args[0], &value)) return 0; @@ -359,6 +365,8 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) seq_puts(m, ",allow_other"); if (fc->flags & FUSE_KERNEL_CACHE) seq_puts(m, ",kernel_cache"); + if (fc->flags & FUSE_DIRECT_IO) + seq_puts(m, ",direct_io"); if (fc->max_read != ~0) seq_printf(m, ",max_read=%u", fc->max_read); return 0; @@ -489,6 +497,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) fc->max_read = d.max_read; if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages) fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE; + fc->max_write = FUSE_MAX_IN / 2; err = -ENOMEM; root = get_root_inode(sb, d.rootmode); |