| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu) |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| */ |
| #include "fuse_i.h" |
| |
| #include <linux/pagemap.h> |
| #include <linux/slab.h> |
| #ifdef KERNEL_2_6 |
| #include <linux/backing-dev.h> |
| #include <linux/writeback.h> |
| #endif |
| |
| #ifndef KERNEL_2_6 |
| #define PageUptodate(page) Page_Uptodate(page) |
| #ifndef NO_MM |
| #define filemap_fdatawrite filemap_fdatasync |
| #else |
| #define filemap_fdatawrite do {} while (0) |
| #endif |
| #endif |
| |
| static int fuse_open(struct inode *inode, struct file *file) |
| { |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in in = FUSE_IN_INIT; |
| struct fuse_out out = FUSE_OUT_INIT; |
| struct fuse_open_in inarg; |
| int err; |
| |
| err = generic_file_open(inode, file); |
| if (err) |
| return err; |
| |
| /* If opening the root node, no lookup has been performed on |
| it, so the attributes must be refreshed */ |
| if (inode->i_ino == FUSE_ROOT_INO) { |
| int err = fuse_do_getattr(inode); |
| if (err) |
| return err; |
| } |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.flags = file->f_flags & ~O_EXCL; |
| |
| in.h.opcode = FUSE_OPEN; |
| in.h.ino = inode->i_ino; |
| in.numargs = 1; |
| in.args[0].size = sizeof(inarg); |
| in.args[0].value = &inarg; |
| request_send(fc, &in, &out); |
| if (!out.h.error && !(fc->flags & FUSE_KERNEL_CACHE)) { |
| #ifdef KERNEL_2_6 |
| invalidate_inode_pages(inode->i_mapping); |
| #else |
| invalidate_inode_pages(inode); |
| #endif |
| } |
| |
| return out.h.error; |
| } |
| |
| static int fuse_release(struct inode *inode, struct file *file) |
| { |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in *in = NULL; |
| struct fuse_open_in *inarg = NULL; |
| unsigned int s = sizeof(struct fuse_in) + sizeof(struct fuse_open_in); |
| |
| if (file->f_mode & FMODE_WRITE) |
| filemap_fdatawrite(inode->i_mapping); |
| |
| in = kmalloc(s, GFP_NOFS); |
| if (!in) |
| return -ENOMEM; |
| memset(in, 0, s); |
| inarg = (struct fuse_open_in *) (in + 1); |
| inarg->flags = file->f_flags & ~O_EXCL; |
| |
| in->h.opcode = FUSE_RELEASE; |
| in->h.ino = inode->i_ino; |
| in->numargs = 1; |
| in->args[0].size = sizeof(struct fuse_open_in); |
| in->args[0].value = inarg; |
| if (!request_send_noreply(fc, in)) |
| return 0; |
| |
| kfree(in); |
| return 0; |
| } |
| |
| static int fuse_fsync(struct file *file, struct dentry *de, int datasync) |
| { |
| struct inode *inode = de->d_inode; |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in in = FUSE_IN_INIT; |
| struct fuse_out out = FUSE_OUT_INIT; |
| struct fuse_fsync_in inarg; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.datasync = datasync; |
| |
| in.h.opcode = FUSE_FSYNC; |
| in.h.ino = inode->i_ino; |
| in.numargs = 1; |
| in.args[0].size = sizeof(inarg); |
| in.args[0].value = &inarg; |
| request_send(fc, &in, &out); |
| return out.h.error; |
| |
| /* FIXME: need to ensure, that all write requests issued |
| before this request are completed. Should userspace take |
| care of this? */ |
| } |
| |
| static int fuse_readpage(struct file *file, struct page *page) |
| { |
| struct inode *inode = page->mapping->host; |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in in = FUSE_IN_INIT; |
| struct fuse_out out = FUSE_OUT_INIT; |
| struct fuse_read_in inarg; |
| char *buffer; |
| |
| buffer = kmap(page); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.offset = (unsigned long long) page->index << PAGE_CACHE_SHIFT; |
| inarg.size = PAGE_CACHE_SIZE; |
| |
| in.h.opcode = FUSE_READ; |
| in.h.ino = inode->i_ino; |
| in.numargs = 1; |
| in.args[0].size = sizeof(inarg); |
| in.args[0].value = &inarg; |
| out.argvar = 1; |
| out.numargs = 1; |
| out.args[0].size = PAGE_CACHE_SIZE; |
| out.args[0].value = buffer; |
| |
| request_send(fc, &in, &out); |
| if (!out.h.error) { |
| size_t outsize = out.args[0].size; |
| if (outsize < PAGE_CACHE_SIZE) |
| memset(buffer + outsize, 0, PAGE_CACHE_SIZE - outsize); |
| flush_dcache_page(page); |
| SetPageUptodate(page); |
| } |
| |
| kunmap(page); |
| unlock_page(page); |
| |
| return out.h.error; |
| } |
| |
| static int fuse_is_block_uptodate(struct address_space *mapping, |
| struct inode *inode, size_t bl_index) |
| { |
| size_t index = bl_index << FUSE_BLOCK_PAGE_SHIFT; |
| size_t end_index = ((bl_index + 1) << FUSE_BLOCK_PAGE_SHIFT) - 1; |
| size_t file_end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT; |
| |
| if (end_index > file_end_index) |
| end_index = file_end_index; |
| |
| for (; index <= end_index; index++) { |
| struct page *page = find_get_page(mapping, index); |
| |
| if (!page) |
| return 0; |
| |
| if (!PageUptodate(page)) { |
| page_cache_release(page); |
| return 0; |
| } |
| |
| page_cache_release(page); |
| } |
| |
| return 1; |
| } |
| |
| |
| static int fuse_cache_block(struct address_space *mapping, |
| struct inode *inode, char *bl_buf, |
| size_t bl_index) |
| { |
| size_t start_index = bl_index << FUSE_BLOCK_PAGE_SHIFT; |
| size_t end_index = ((bl_index + 1) << FUSE_BLOCK_PAGE_SHIFT) - 1; |
| size_t file_end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT; |
| |
| int i; |
| |
| if (end_index > file_end_index) |
| end_index = file_end_index; |
| |
| for (i = 0; start_index + i <= end_index; i++) { |
| size_t index = start_index + i; |
| struct page *page; |
| char *buffer; |
| |
| page = grab_cache_page(mapping, index); |
| if (!page) |
| return -1; |
| |
| if (!PageUptodate(page)) { |
| buffer = kmap(page); |
| memcpy(buffer, bl_buf + i * PAGE_CACHE_SIZE, |
| PAGE_CACHE_SIZE); |
| flush_dcache_page(page); |
| SetPageUptodate(page); |
| kunmap(page); |
| } |
| |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| |
| return 0; |
| } |
| |
| static int fuse_file_read_block(struct inode *inode, char *bl_buf, |
| size_t bl_index) |
| { |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in in = FUSE_IN_INIT; |
| struct fuse_out out = FUSE_OUT_INIT; |
| struct fuse_read_in inarg; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.offset = bl_index << FUSE_BLOCK_SHIFT; |
| inarg.size = FUSE_BLOCK_SIZE; |
| |
| in.h.opcode = FUSE_READ; |
| in.h.ino = inode->i_ino; |
| in.numargs = 1; |
| in.args[0].size = sizeof(inarg); |
| in.args[0].value = &inarg; |
| out.argvar = 1; |
| out.numargs = 1; |
| out.args[0].size = FUSE_BLOCK_SIZE; |
| out.args[0].value = bl_buf; |
| |
| request_send(fc, &in, &out); |
| |
| if (!out.h.error) { |
| size_t outsize = out.args[0].size; |
| if (outsize < FUSE_BLOCK_SIZE) |
| memset(bl_buf + outsize, 0, FUSE_BLOCK_SIZE - outsize); |
| } |
| |
| return out.h.error; |
| } |
| |
| static void fuse_file_bigread(struct address_space *mapping, |
| struct inode *inode, loff_t pos, size_t count) |
| { |
| size_t bl_index = pos >> FUSE_BLOCK_SHIFT; |
| size_t bl_end_index = (pos + count) >> FUSE_BLOCK_SHIFT; |
| size_t bl_file_end_index = i_size_read(inode) >> FUSE_BLOCK_SHIFT; |
| |
| if (bl_end_index > bl_file_end_index) |
| bl_end_index = bl_file_end_index; |
| |
| while (bl_index <= bl_end_index) { |
| int res; |
| char *bl_buf = kmalloc(FUSE_BLOCK_SIZE, GFP_NOFS); |
| if (!bl_buf) |
| break; |
| res = fuse_is_block_uptodate(mapping, inode, bl_index); |
| if (!res) |
| res = fuse_file_read_block(inode, bl_buf, bl_index); |
| if (!res) |
| fuse_cache_block(mapping, inode, bl_buf, bl_index); |
| kfree(bl_buf); |
| bl_index++; |
| } |
| } |
| |
| static ssize_t fuse_file_read(struct file *filp, char *buf, |
| size_t count, loff_t * ppos) |
| { |
| struct address_space *mapping = filp->f_dentry->d_inode->i_mapping; |
| struct inode *inode = mapping->host; |
| struct fuse_conn *fc = INO_FC(inode); |
| |
| if (fc->flags & FUSE_LARGE_READ) |
| fuse_file_bigread(mapping, inode, *ppos, count); |
| |
| return generic_file_read(filp, buf, count, ppos); |
| } |
| |
| static int write_buffer(struct inode *inode, struct page *page, |
| unsigned offset, size_t count) |
| { |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in in = FUSE_IN_INIT; |
| struct fuse_out out = FUSE_OUT_INIT; |
| struct fuse_write_in inarg; |
| char *buffer; |
| |
| buffer = kmap(page); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.offset = ((unsigned long long) page->index << PAGE_CACHE_SHIFT) + |
| offset; |
| inarg.size = count; |
| |
| in.h.opcode = FUSE_WRITE; |
| in.h.ino = inode->i_ino; |
| in.numargs = 2; |
| in.args[0].size = sizeof(inarg); |
| in.args[0].value = &inarg; |
| in.args[1].size = count; |
| in.args[1].value = buffer + offset; |
| request_send(fc, &in, &out); |
| kunmap(page); |
| if (out.h.error) |
| SetPageError(page); |
| |
| return out.h.error; |
| } |
| |
| static int get_write_count(struct inode *inode, struct page *page) |
| { |
| unsigned long end_index; |
| loff_t size = i_size_read(inode); |
| int count; |
| |
| end_index = size >> PAGE_CACHE_SHIFT; |
| if (page->index < end_index) |
| count = PAGE_CACHE_SIZE; |
| else { |
| count = size & (PAGE_CACHE_SIZE - 1); |
| if (page->index > end_index || count == 0) |
| return 0; |
| } |
| return count; |
| } |
| |
| #ifdef KERNEL_2_6 |
| |
| static void write_buffer_end(struct fuse_conn *fc, struct fuse_in *in, |
| struct fuse_out *out, void *_page) |
| { |
| struct page *page = (struct page *) _page; |
| |
| lock_page(page); |
| if (out->h.error) { |
| SetPageError(page); |
| if (out->h.error == -ENOSPC) |
| set_bit(AS_ENOSPC, &page->mapping->flags); |
| else |
| set_bit(AS_EIO, &page->mapping->flags); |
| } |
| end_page_writeback(page); |
| kunmap(page); |
| unlock_page(page); |
| kfree(in); |
| } |
| |
| static int write_buffer_nonblock(struct inode *inode, struct page *page, |
| unsigned offset, size_t count) |
| { |
| int err; |
| struct fuse_conn *fc = INO_FC(inode); |
| struct fuse_in *in = NULL; |
| struct fuse_out *out = NULL; |
| struct fuse_write_in *inarg = NULL; |
| char *buffer; |
| unsigned int s = sizeof(struct fuse_in) + sizeof(struct fuse_out) + |
| sizeof(struct fuse_write_in); |
| |
| in = kmalloc(s, GFP_NOFS); |
| if (!in) |
| return -ENOMEM; |
| memset(in, 0, s); |
| out = (struct fuse_out *)(in + 1); |
| inarg = (struct fuse_write_in *)(out + 1); |
| |
| buffer = kmap(page); |
| |
| inarg->offset = ((unsigned long long) page->index << PAGE_CACHE_SHIFT) + offset; |
| inarg->size = count; |
| |
| in->h.opcode = FUSE_WRITE; |
| in->h.ino = inode->i_ino; |
| in->numargs = 2; |
| in->args[0].size = sizeof(struct fuse_write_in); |
| in->args[0].value = inarg; |
| in->args[1].size = count; |
| in->args[1].value = buffer + offset; |
| err = request_send_nonblock(fc, in, out, write_buffer_end, page); |
| if (err) { |
| if (err != -EWOULDBLOCK) |
| SetPageError(page); |
| kunmap(page); |
| kfree(in); |
| } |
| return err; |
| } |
| |
| static int fuse_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| int err; |
| struct inode *inode = page->mapping->host; |
| unsigned count = get_write_count(inode, page); |
| |
| err = -EINVAL; |
| if (count) { |
| /* FIXME: check sync_mode, and wait for previous writes (or |
| signal userspace to do this) */ |
| if (wbc->nonblocking) { |
| err = write_buffer_nonblock(inode, page, 0, count); |
| if (!err) |
| SetPageWriteback(page); |
| else if (err == -EWOULDBLOCK) { |
| __set_page_dirty_nobuffers(page); |
| err = 0; |
| } |
| } else |
| err = write_buffer(inode, page, 0, count); |
| } |
| |
| unlock_page(page); |
| return err; |
| } |
| #else |
| static int fuse_writepage(struct page *page) |
| { |
| int err; |
| struct inode *inode = page->mapping->host; |
| int count = get_write_count(inode, page); |
| err = -EINVAL; |
| if (count) |
| err = write_buffer(inode, page, 0, count); |
| |
| unlock_page(page); |
| return err; |
| } |
| #endif |
| |
| static int fuse_prepare_write(struct file *file, struct page *page, |
| unsigned offset, unsigned to) |
| { |
| /* No op */ |
| return 0; |
| } |
| |
| static int fuse_commit_write(struct file *file, struct page *page, |
| unsigned offset, unsigned to) |
| { |
| int err; |
| struct inode *inode = page->mapping->host; |
| |
| err = write_buffer(inode, page, offset, to - offset); |
| if (!err) { |
| loff_t pos = (page->index << PAGE_CACHE_SHIFT) + to; |
| if (pos > i_size_read(inode)) |
| i_size_write(inode, pos); |
| } |
| return err; |
| } |
| |
| static struct file_operations fuse_file_operations = { |
| .read = fuse_file_read, |
| .write = generic_file_write, |
| .mmap = generic_file_mmap, |
| .open = fuse_open, |
| .release = fuse_release, |
| .fsync = fuse_fsync, |
| #ifdef KERNEL_2_6 |
| .sendfile = generic_file_sendfile, |
| #endif |
| }; |
| |
| static struct address_space_operations fuse_file_aops = { |
| .readpage = fuse_readpage, |
| .writepage = fuse_writepage, |
| .prepare_write = fuse_prepare_write, |
| .commit_write = fuse_commit_write, |
| }; |
| |
| void fuse_init_file_inode(struct inode *inode) |
| { |
| #ifdef KERNEL_2_6 |
| struct fuse_conn *fc = INO_FC(inode); |
| /* Readahead somehow defeats big reads on 2.6 (says Michael |
| Grigoriev) */ |
| if (fc->flags & FUSE_LARGE_READ) |
| inode->i_mapping->backing_dev_info->ra_pages = 0; |
| #endif |
| inode->i_fop = &fuse_file_operations; |
| inode->i_data.a_ops = &fuse_file_aops; |
| } |
| |
| /* |
| * Local Variables: |
| * indent-tabs-mode: t |
| * c-basic-offset: 8 |
| * End: |
| */ |