* [patch 0/3] fuse: implement missing functionality on "direct_io" files
@ 2009-03-30 20:00 Miklos Szeredi
2009-03-30 20:02 ` [patch 1/3] fuse: allow kernel to access " Miklos Szeredi
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Miklos Szeredi @ 2009-03-30 20:00 UTC (permalink / raw)
To: linux-fsdevel; +Cc: jens.axboe, linux-kernel
Fuse allows filesystems to bypass the page cache using the "direct_io"
flag. This is not the same as O_DIRECT, it's dictated by the
filesystem not the application.
Some functionality didn't work in this mode, however. This short
patchset improves that:
1. fuse: allow kernel to access "direct_io" files
2. fuse: allow private mappings of "direct_io" files
3. splice: implement default splice_read method
The third patch is not fuse specific, it implements ->splice_read()
for any filesystem which doesn't provide one.
Comments are welcome.
Thanks,
Miklos
^ permalink raw reply [flat|nested] 6+ messages in thread* [patch 1/3] fuse: allow kernel to access "direct_io" files 2009-03-30 20:00 [patch 0/3] fuse: implement missing functionality on "direct_io" files Miklos Szeredi @ 2009-03-30 20:02 ` Miklos Szeredi 2009-03-30 20:03 ` [patch 2/3] fuse: allow private mappings of " Miklos Szeredi 2009-03-30 20:04 ` [patch 3/3] splice: implement default splice_read method Miklos Szeredi 2 siblings, 0 replies; 6+ messages in thread From: Miklos Szeredi @ 2009-03-30 20:02 UTC (permalink / raw) To: linux-fsdevel; +Cc: linux-kernel From: Miklos Szeredi <mszeredi@suse.cz> Allow the kernel read and write on "direct_io" files. This is necessary for nfs export and execute support. The implementation is simple: if an access from the kernel is detected, don't perform get_user_pages(), just use the kernel address provided by the requester to copy from/to the userspace filesystem. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- fs/fuse/dir.c | 1 + fs/fuse/file.c | 53 ++++++++++++++++++++++++++++++++++++++++------------- 2 files changed, 41 insertions(+), 13 deletions(-) Index: linux-2.6/fs/fuse/file.c =================================================================== --- linux-2.6.orig/fs/fuse/file.c 2009-03-25 10:30:52.000000000 +0100 +++ linux-2.6/fs/fuse/file.c 2009-03-25 10:35:22.000000000 +0100 @@ -386,7 +386,6 @@ void fuse_read_fill(struct fuse_req *req req->in.numargs = 1; req->in.args[0].size = sizeof(struct fuse_read_in); req->in.args[0].value = inarg; - req->out.argpages = 1; req->out.argvar = 1; req->out.numargs = 1; req->out.args[0].size = count; @@ -453,6 +452,7 @@ static int fuse_readpage(struct file *fi attr_ver = fuse_get_attr_version(fc); req->out.page_zeroing = 1; + req->out.argpages = 1; req->num_pages = 1; req->pages[0] = page; num_read = fuse_send_read(req, file, inode, pos, count, NULL); @@ -510,6 +510,8 @@ static void fuse_send_readpages(struct f struct fuse_conn *fc = get_fuse_conn(inode); loff_t pos = page_offset(req->pages[0]); size_t count = req->num_pages << PAGE_CACHE_SHIFT; + + req->out.argpages = 1; req->out.page_zeroing = 1; fuse_read_fill(req, file, inode, pos, count, FUSE_READ); req->misc.read.attr_ver = fuse_get_attr_version(fc); @@ -621,7 +623,6 @@ static void fuse_write_fill(struct fuse_ inarg->flags = file ? file->f_flags : 0; req->in.h.opcode = FUSE_WRITE; req->in.h.nodeid = get_node_id(inode); - req->in.argpages = 1; req->in.numargs = 2; if (fc->minor < 9) req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE; @@ -695,6 +696,7 @@ static int fuse_buffered_write(struct fi if (IS_ERR(req)) return PTR_ERR(req); + req->in.argpages = 1; req->num_pages = 1; req->pages[0] = page; req->page_offset = offset; @@ -771,6 +773,7 @@ static ssize_t fuse_fill_write_pages(str size_t count = 0; int err; + req->in.argpages = 1; req->page_offset = offset; do { @@ -935,21 +938,28 @@ static void fuse_release_user_pages(stru } static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, - unsigned nbytes, int write) + unsigned *nbytesp, int write) { + unsigned nbytes = *nbytesp; 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; + /* Special case for kernel I/O: can copy directly into the buffer */ + if (segment_eq(get_fs(), KERNEL_DS)) { + if (write) + req->in.args[1].value = (void *) user_addr; + else + req->out.args[0].value = (void *) user_addr; + + return 0; + } nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ); down_read(¤t->mm->mmap_sem); - npages = get_user_pages(current, current->mm, user_addr, npages, write, + npages = get_user_pages(current, current->mm, user_addr, npages, !write, 0, req->pages, NULL); up_read(¤t->mm->mmap_sem); if (npages < 0) @@ -957,6 +967,15 @@ static int fuse_get_user_pages(struct fu req->num_pages = npages; req->page_offset = offset; + + if (write) + req->in.argpages = 1; + else + req->out.argpages = 1; + + nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset; + *nbytesp = min(*nbytesp, nbytes); + return 0; } @@ -979,15 +998,13 @@ static ssize_t fuse_direct_io(struct fil while (count) { size_t nres; - size_t nbytes_limit = min(count, nmax); - size_t nbytes; - int err = fuse_get_user_pages(req, buf, nbytes_limit, !write); + size_t nbytes = min(count, nmax); + int err = fuse_get_user_pages(req, buf, &nbytes, write); if (err) { res = err; break; } - nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset; - nbytes = min(nbytes_limit, nbytes); + if (write) nres = fuse_send_write(req, file, inode, pos, nbytes, current->files); @@ -1163,6 +1180,7 @@ static int fuse_writepage_locked(struct fuse_write_fill(req, NULL, ff, inode, page_offset(page), 0, 1); copy_highpage(tmp_page, page); + req->in.argpages = 1; req->num_pages = 1; req->pages[0] = tmp_page; req->page_offset = 0; Index: linux-2.6/fs/fuse/dir.c =================================================================== --- linux-2.6.orig/fs/fuse/dir.c 2009-03-25 10:31:06.000000000 +0100 +++ linux-2.6/fs/fuse/dir.c 2009-03-25 10:31:10.000000000 +0100 @@ -1032,6 +1032,7 @@ static int fuse_readdir(struct file *fil fuse_put_request(fc, req); return -ENOMEM; } + req->out.argpages = 1; req->num_pages = 1; req->pages[0] = page; fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR); ^ permalink raw reply [flat|nested] 6+ messages in thread
* [patch 2/3] fuse: allow private mappings of "direct_io" files 2009-03-30 20:00 [patch 0/3] fuse: implement missing functionality on "direct_io" files Miklos Szeredi 2009-03-30 20:02 ` [patch 1/3] fuse: allow kernel to access " Miklos Szeredi @ 2009-03-30 20:03 ` Miklos Szeredi 2009-03-30 20:04 ` [patch 3/3] splice: implement default splice_read method Miklos Szeredi 2 siblings, 0 replies; 6+ messages in thread From: Miklos Szeredi @ 2009-03-30 20:03 UTC (permalink / raw) To: linux-fsdevel; +Cc: linux-kernel From: Miklos Szeredi <mszeredi@suse.cz> Allow MAP_PRIVATE mmaps of "direct_io" files. This is necessary for execute support. MAP_SHARED mappings require some sort of coherency between the underlying file and the mapping. With "direct_io" it is difficult to provide this, so for the moment just disallow shared (read-write and read-only) mappings altogether. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- fs/fuse/file.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) Index: linux-2.6/fs/fuse/file.c =================================================================== --- linux-2.6.orig/fs/fuse/file.c 2009-03-30 18:47:55.000000000 +0200 +++ linux-2.6/fs/fuse/file.c 2009-03-30 19:07:11.000000000 +0200 @@ -1291,6 +1291,15 @@ static int fuse_file_mmap(struct file *f return 0; } +static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma) +{ + /* Can't provide the coherency needed for MAP_SHARED */ + if (vma->vm_flags & VM_MAYSHARE) + return -ENODEV; + + return generic_file_mmap(file, vma); +} + static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, struct file_lock *fl) { @@ -1925,6 +1934,7 @@ static const struct file_operations fuse .llseek = fuse_file_llseek, .read = fuse_direct_read, .write = fuse_direct_write, + .mmap = fuse_direct_mmap, .open = fuse_open, .flush = fuse_flush, .release = fuse_release, @@ -1934,7 +1944,7 @@ static const struct file_operations fuse .unlocked_ioctl = fuse_file_ioctl, .compat_ioctl = fuse_file_compat_ioctl, .poll = fuse_file_poll, - /* no mmap and splice_read */ + /* no splice_read */ }; static const struct address_space_operations fuse_file_aops = { ^ permalink raw reply [flat|nested] 6+ messages in thread
* [patch 3/3] splice: implement default splice_read method 2009-03-30 20:00 [patch 0/3] fuse: implement missing functionality on "direct_io" files Miklos Szeredi 2009-03-30 20:02 ` [patch 1/3] fuse: allow kernel to access " Miklos Szeredi 2009-03-30 20:03 ` [patch 2/3] fuse: allow private mappings of " Miklos Szeredi @ 2009-03-30 20:04 ` Miklos Szeredi 2009-03-30 20:59 ` Brad Boyer 2 siblings, 1 reply; 6+ messages in thread From: Miklos Szeredi @ 2009-03-30 20:04 UTC (permalink / raw) To: linux-fsdevel; +Cc: jens.axboe, linux-kernel From: Miklos Szeredi <mszeredi@suse.cz> If f_op->splice_read() is not implemented fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- fs/pipe.c | 14 +++++ fs/splice.c | 120 ++++++++++++++++++++++++++++++++++++++++++++-- include/linux/fs.h | 2 include/linux/pipe_fs_i.h | 2 4 files changed, 133 insertions(+), 5 deletions(-) Index: linux-2.6/fs/pipe.c =================================================================== --- linux-2.6.orig/fs/pipe.c 2009-03-30 21:11:58.000000000 +0200 +++ linux-2.6/fs/pipe.c 2009-03-30 21:22:06.000000000 +0200 @@ -268,6 +268,20 @@ int generic_pipe_buf_confirm(struct pipe return 0; } +/** + * generic_pipe_buf_release - put a reference to a &struct pipe_buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer to put a reference to + * + * Description: + * This function releases a reference to @buf. + */ +void generic_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + page_cache_release(buf->page); +} + static const struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, .map = generic_pipe_buf_map, Index: linux-2.6/fs/splice.c =================================================================== --- linux-2.6.orig/fs/splice.c 2009-03-30 21:11:58.000000000 +0200 +++ linux-2.6/fs/splice.c 2009-03-30 21:22:06.000000000 +0200 @@ -509,9 +509,116 @@ ssize_t generic_file_splice_read(struct return ret; } - EXPORT_SYMBOL(generic_file_splice_read); +static const struct pipe_buf_operations default_pipe_buf_ops = { + .can_merge = 0, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .confirm = generic_pipe_buf_confirm, + .release = generic_pipe_buf_release, + .steal = generic_pipe_buf_steal, + .get = generic_pipe_buf_get, +}; + +static ssize_t kernel_readv(struct file *file, const struct iovec *vec, + unsigned long vlen, loff_t offset) +{ + mm_segment_t old_fs; + loff_t pos = offset; + ssize_t res; + + old_fs = get_fs(); + set_fs(get_ds()); + /* The cast to a user pointer is valid due to the set_fs() */ + res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos); + set_fs(old_fs); + + return res; +} + +ssize_t default_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + unsigned int nr_pages; + unsigned int nr_freed; + size_t offset; + struct page *pages[PIPE_BUFFERS]; + struct partial_page partial[PIPE_BUFFERS]; + struct iovec vec[PIPE_BUFFERS]; + pgoff_t index; + ssize_t res; + size_t this_len; + int error; + int i; + struct splice_pipe_desc spd = { + .pages = pages, + .partial = partial, + .flags = flags, + .ops = &default_pipe_buf_ops, + .spd_release = spd_release_page, + }; + + index = *ppos >> PAGE_CACHE_SHIFT; + offset = *ppos & ~PAGE_CACHE_MASK; + nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + + for (i = 0; i < nr_pages && i < PIPE_BUFFERS && len; i++) { + struct page *page; + + page = alloc_page(GFP_HIGHUSER); + error = -ENOMEM; + if (!page) + goto err; + + this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset); + vec[i].iov_base = (void __user *) kmap(page); + vec[i].iov_len = this_len; + pages[i] = page; + spd.nr_pages++; + len -= this_len; + offset = 0; + } + + res = kernel_readv(in, vec, spd.nr_pages, *ppos); + if (res < 0) + goto err; + + error = 0; + if (!res) + goto err; + + nr_freed = 0; + for (i = 0; i < spd.nr_pages; i++) { + kunmap(pages[i]); + this_len = min_t(size_t, vec[i].iov_len, res); + partial[i].offset = 0; + partial[i].len = this_len; + if (!this_len) { + __free_page(pages[i]); + pages[i] = NULL; + nr_freed++; + } + res -= this_len; + } + spd.nr_pages -= nr_freed; + + res = splice_to_pipe(pipe, &spd); + if (res > 0) + *ppos += res; + + return res; + +err: + for (i = 0; i < spd.nr_pages; i++) { + kunmap(pages[i]); + __free_page(pages[i]); + } + return error; +} +EXPORT_SYMBOL(default_file_splice_read); + /* * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' * using sendpage(). Return the number of bytes sent. @@ -916,11 +1023,10 @@ static long do_splice_to(struct file *in struct pipe_inode_info *pipe, size_t len, unsigned int flags) { + ssize_t (*splice_read)(struct file *, loff_t *, + struct pipe_inode_info *, size_t, unsigned int); int ret; - if (unlikely(!in->f_op || !in->f_op->splice_read)) - return -EINVAL; - if (unlikely(!(in->f_mode & FMODE_READ))) return -EBADF; @@ -928,7 +1034,11 @@ static long do_splice_to(struct file *in if (unlikely(ret < 0)) return ret; - return in->f_op->splice_read(in, ppos, pipe, len, flags); + splice_read = in->f_op->splice_read; + if (!splice_read) + splice_read = default_file_splice_read; + + return splice_read(in, ppos, pipe, len, flags); } /** Index: linux-2.6/include/linux/pipe_fs_i.h =================================================================== --- linux-2.6.orig/include/linux/pipe_fs_i.h 2009-03-30 21:11:58.000000000 +0200 +++ linux-2.6/include/linux/pipe_fs_i.h 2009-03-30 21:22:06.000000000 +0200 @@ -147,5 +147,7 @@ void generic_pipe_buf_unmap(struct pipe_ void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); +void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); + #endif Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2009-03-30 21:13:11.000000000 +0200 +++ linux-2.6/include/linux/fs.h 2009-03-30 21:22:06.000000000 +0200 @@ -2126,6 +2126,8 @@ extern int generic_segment_checks(const /* fs/splice.c */ extern ssize_t generic_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); +extern ssize_t default_file_splice_read(struct file *, loff_t *, + struct pipe_inode_info *, size_t, unsigned int); extern ssize_t generic_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); extern ssize_t generic_file_splice_write_nolock(struct pipe_inode_info *, ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [patch 3/3] splice: implement default splice_read method 2009-03-30 20:04 ` [patch 3/3] splice: implement default splice_read method Miklos Szeredi @ 2009-03-30 20:59 ` Brad Boyer 2009-03-31 10:07 ` Miklos Szeredi 0 siblings, 1 reply; 6+ messages in thread From: Brad Boyer @ 2009-03-30 20:59 UTC (permalink / raw) To: Miklos Szeredi; +Cc: linux-fsdevel, jens.axboe, linux-kernel On Mon, Mar 30, 2009 at 10:04:28PM +0200, Miklos Szeredi wrote: > From: Miklos Szeredi <mszeredi@suse.cz> > > If f_op->splice_read() is not implemented fall back to a plain read. > Use vfs_readv() to read into previously allocated pages. > > This will allow splice and functions using splice, such as the loop > device, to work on all filesystems. This includes "direct_io" files > in fuse which bypass the page cache. Based on your description, I would have expected this patch to make the loop driver work seamlessly. Unless I'm misreading something, I think the loop driver will still error out if the fs driver in question doesn't explicitly set splice_read.o >From drivers/block/loop.c: 724 /* new backing store needs to support loop (eg splice_read) */ 725 if (!inode->i_fop->splice_read) 726 goto out_putf; 727 Did you accidentally leave out some changes? Please let me know if I am missing something obvious. Brad Boyer flar@allandria.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [patch 3/3] splice: implement default splice_read method 2009-03-30 20:59 ` Brad Boyer @ 2009-03-31 10:07 ` Miklos Szeredi 0 siblings, 0 replies; 6+ messages in thread From: Miklos Szeredi @ 2009-03-31 10:07 UTC (permalink / raw) To: flar; +Cc: miklos, linux-fsdevel, jens.axboe, linux-kernel On Mon, 30 Mar 2009, Brad Boyer wrote: > Based on your description, I would have expected this patch to make > the loop driver work seamlessly. Unless I'm misreading something, I > think the loop driver will still error out if the fs driver in question > doesn't explicitly set splice_read.o You're right. Here's an updated patch. Thanks, Miklos --- From: Miklos Szeredi <mszeredi@suse.cz> If f_op->splice_read() is not implemented fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- drivers/block/loop.c | 11 ---- fs/coda/file.c | 9 ++- fs/fuse/file.c | 1 fs/pipe.c | 14 +++++ fs/read_write.c | 7 -- fs/splice.c | 120 ++++++++++++++++++++++++++++++++++++++++++++-- include/linux/fs.h | 2 include/linux/pipe_fs_i.h | 1 8 files changed, 140 insertions(+), 25 deletions(-) Index: linux-2.6/fs/pipe.c =================================================================== --- linux-2.6.orig/fs/pipe.c 2009-03-31 11:43:55.000000000 +0200 +++ linux-2.6/fs/pipe.c 2009-03-31 11:44:12.000000000 +0200 @@ -268,6 +268,20 @@ int generic_pipe_buf_confirm(struct pipe return 0; } +/** + * generic_pipe_buf_release - put a reference to a &struct pipe_buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer to put a reference to + * + * Description: + * This function releases a reference to @buf. + */ +void generic_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + page_cache_release(buf->page); +} + static const struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, .map = generic_pipe_buf_map, Index: linux-2.6/fs/splice.c =================================================================== --- linux-2.6.orig/fs/splice.c 2009-03-31 11:43:55.000000000 +0200 +++ linux-2.6/fs/splice.c 2009-03-31 11:44:12.000000000 +0200 @@ -509,9 +509,116 @@ ssize_t generic_file_splice_read(struct return ret; } - EXPORT_SYMBOL(generic_file_splice_read); +static const struct pipe_buf_operations default_pipe_buf_ops = { + .can_merge = 0, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .confirm = generic_pipe_buf_confirm, + .release = generic_pipe_buf_release, + .steal = generic_pipe_buf_steal, + .get = generic_pipe_buf_get, +}; + +static ssize_t kernel_readv(struct file *file, const struct iovec *vec, + unsigned long vlen, loff_t offset) +{ + mm_segment_t old_fs; + loff_t pos = offset; + ssize_t res; + + old_fs = get_fs(); + set_fs(get_ds()); + /* The cast to a user pointer is valid due to the set_fs() */ + res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos); + set_fs(old_fs); + + return res; +} + +ssize_t default_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + unsigned int nr_pages; + unsigned int nr_freed; + size_t offset; + struct page *pages[PIPE_BUFFERS]; + struct partial_page partial[PIPE_BUFFERS]; + struct iovec vec[PIPE_BUFFERS]; + pgoff_t index; + ssize_t res; + size_t this_len; + int error; + int i; + struct splice_pipe_desc spd = { + .pages = pages, + .partial = partial, + .flags = flags, + .ops = &default_pipe_buf_ops, + .spd_release = spd_release_page, + }; + + index = *ppos >> PAGE_CACHE_SHIFT; + offset = *ppos & ~PAGE_CACHE_MASK; + nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + + for (i = 0; i < nr_pages && i < PIPE_BUFFERS && len; i++) { + struct page *page; + + page = alloc_page(GFP_HIGHUSER); + error = -ENOMEM; + if (!page) + goto err; + + this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset); + vec[i].iov_base = (void __user *) kmap(page); + vec[i].iov_len = this_len; + pages[i] = page; + spd.nr_pages++; + len -= this_len; + offset = 0; + } + + res = kernel_readv(in, vec, spd.nr_pages, *ppos); + if (res < 0) + goto err; + + error = 0; + if (!res) + goto err; + + nr_freed = 0; + for (i = 0; i < spd.nr_pages; i++) { + kunmap(pages[i]); + this_len = min_t(size_t, vec[i].iov_len, res); + partial[i].offset = 0; + partial[i].len = this_len; + if (!this_len) { + __free_page(pages[i]); + pages[i] = NULL; + nr_freed++; + } + res -= this_len; + } + spd.nr_pages -= nr_freed; + + res = splice_to_pipe(pipe, &spd); + if (res > 0) + *ppos += res; + + return res; + +err: + for (i = 0; i < spd.nr_pages; i++) { + kunmap(pages[i]); + __free_page(pages[i]); + } + return error; +} +EXPORT_SYMBOL(default_file_splice_read); + /* * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' * using sendpage(). Return the number of bytes sent. @@ -916,11 +1023,10 @@ static long do_splice_to(struct file *in struct pipe_inode_info *pipe, size_t len, unsigned int flags) { + ssize_t (*splice_read)(struct file *, loff_t *, + struct pipe_inode_info *, size_t, unsigned int); int ret; - if (unlikely(!in->f_op || !in->f_op->splice_read)) - return -EINVAL; - if (unlikely(!(in->f_mode & FMODE_READ))) return -EBADF; @@ -928,7 +1034,11 @@ static long do_splice_to(struct file *in if (unlikely(ret < 0)) return ret; - return in->f_op->splice_read(in, ppos, pipe, len, flags); + splice_read = in->f_op->splice_read; + if (!splice_read) + splice_read = default_file_splice_read; + + return splice_read(in, ppos, pipe, len, flags); } /** Index: linux-2.6/include/linux/pipe_fs_i.h =================================================================== --- linux-2.6.orig/include/linux/pipe_fs_i.h 2009-03-31 11:43:55.000000000 +0200 +++ linux-2.6/include/linux/pipe_fs_i.h 2009-03-31 12:04:19.000000000 +0200 @@ -147,5 +147,6 @@ void generic_pipe_buf_unmap(struct pipe_ void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); +void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); #endif Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2009-03-31 11:43:55.000000000 +0200 +++ linux-2.6/include/linux/fs.h 2009-03-31 11:44:12.000000000 +0200 @@ -2126,6 +2126,8 @@ extern int generic_segment_checks(const /* fs/splice.c */ extern ssize_t generic_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); +extern ssize_t default_file_splice_read(struct file *, loff_t *, + struct pipe_inode_info *, size_t, unsigned int); extern ssize_t generic_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); extern ssize_t generic_file_splice_write_nolock(struct pipe_inode_info *, Index: linux-2.6/drivers/block/loop.c =================================================================== --- linux-2.6.orig/drivers/block/loop.c 2009-03-31 11:43:55.000000000 +0200 +++ linux-2.6/drivers/block/loop.c 2009-03-31 11:44:12.000000000 +0200 @@ -721,10 +721,6 @@ static int loop_change_fd(struct loop_de if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) goto out_putf; - /* new backing store needs to support loop (eg splice_read) */ - if (!inode->i_fop->splice_read) - goto out_putf; - /* size of the new backing store needs to be the same */ if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) goto out_putf; @@ -800,12 +796,7 @@ static int loop_set_fd(struct loop_devic error = -EINVAL; if (S_ISREG(inode->i_mode) || S_ISBLK(inode->i_mode)) { const struct address_space_operations *aops = mapping->a_ops; - /* - * If we can't read - sorry. If we only can't write - well, - * it's going to be read-only. - */ - if (!file->f_op->splice_read) - goto out_putf; + if (aops->write_begin) lo_flags |= LO_FLAGS_USE_AOPS; if (!(lo_flags & LO_FLAGS_USE_AOPS) && !file->f_op->write) Index: linux-2.6/fs/coda/file.c =================================================================== --- linux-2.6.orig/fs/coda/file.c 2009-03-31 11:43:55.000000000 +0200 +++ linux-2.6/fs/coda/file.c 2009-03-31 11:44:12.000000000 +0200 @@ -47,6 +47,8 @@ coda_file_splice_read(struct file *coda_ struct pipe_inode_info *pipe, size_t count, unsigned int flags) { + ssize_t (*splice_read)(struct file *, loff_t *, + struct pipe_inode_info *, size_t, unsigned int); struct coda_file_info *cfi; struct file *host_file; @@ -54,10 +56,11 @@ coda_file_splice_read(struct file *coda_ BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); host_file = cfi->cfi_container; - if (!host_file->f_op || !host_file->f_op->splice_read) - return -EINVAL; + splice_read = host_file->f_op->splice_read; + if (!splice_read) + splice_read = default_file_splice_read; - return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags); + return splice_read(host_file, ppos, pipe, count, flags); } static ssize_t Index: linux-2.6/fs/fuse/file.c =================================================================== --- linux-2.6.orig/fs/fuse/file.c 2009-03-31 11:44:12.000000000 +0200 +++ linux-2.6/fs/fuse/file.c 2009-03-31 11:44:12.000000000 +0200 @@ -1944,7 +1944,6 @@ static const struct file_operations fuse .unlocked_ioctl = fuse_file_ioctl, .compat_ioctl = fuse_file_compat_ioctl, .poll = fuse_file_poll, - /* no splice_read */ }; static const struct address_space_operations fuse_file_aops = { Index: linux-2.6/fs/read_write.c =================================================================== --- linux-2.6.orig/fs/read_write.c 2009-03-31 11:44:10.000000000 +0200 +++ linux-2.6/fs/read_write.c 2009-03-31 11:45:48.000000000 +0200 @@ -749,12 +749,6 @@ static ssize_t do_sendfile(int out_fd, i goto out; if (!(in_file->f_mode & FMODE_READ)) goto fput_in; - retval = -EINVAL; - in_inode = in_file->f_path.dentry->d_inode; - if (!in_inode) - goto fput_in; - if (!in_file->f_op || !in_file->f_op->splice_read) - goto fput_in; retval = -ESPIPE; if (!ppos) ppos = &in_file->f_pos; @@ -778,6 +772,7 @@ static ssize_t do_sendfile(int out_fd, i retval = -EINVAL; if (!out_file->f_op || !out_file->f_op->sendpage) goto fput_out; + in_inode = in_file->f_path.dentry->d_inode; out_inode = out_file->f_path.dentry->d_inode; retval = rw_verify_area(WRITE, out_file, &out_file->f_pos, count); if (retval < 0) ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-03-31 10:08 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-03-30 20:00 [patch 0/3] fuse: implement missing functionality on "direct_io" files Miklos Szeredi 2009-03-30 20:02 ` [patch 1/3] fuse: allow kernel to access " Miklos Szeredi 2009-03-30 20:03 ` [patch 2/3] fuse: allow private mappings of " Miklos Szeredi 2009-03-30 20:04 ` [patch 3/3] splice: implement default splice_read method Miklos Szeredi 2009-03-30 20:59 ` Brad Boyer 2009-03-31 10:07 ` Miklos Szeredi
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