| /* |
| * JFFS2 -- Journalling Flash File System, Version 2. |
| * |
| * Copyright © 2001-2007 Red Hat, Inc. |
| * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> |
| * |
| * Created by David Woodhouse <dwmw2@infradead.org> |
| * |
| * For licensing information, see the file 'LICENCE' in this directory. |
| * |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/fs.h> |
| #include <linux/time.h> |
| #include <linux/pagemap.h> |
| #include <linux/highmem.h> |
| #include <linux/crc32.h> |
| #include <linux/jffs2.h> |
| #include "nodelist.h" |
| |
| static int jffs2_write_end(struct file *filp, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *pg, void *fsdata); |
| static int jffs2_write_begin(struct file *filp, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata); |
| static int jffs2_readpage (struct file *filp, struct page *pg); |
| |
| int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
| { |
| struct inode *inode = filp->f_mapping->host; |
| struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| int ret; |
| |
| ret = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| if (ret) |
| return ret; |
| |
| inode_lock(inode); |
| /* Trigger GC to flush any pending writes for this inode */ |
| jffs2_flush_wbuf_gc(c, inode->i_ino); |
| inode_unlock(inode); |
| |
| return 0; |
| } |
| |
| const struct file_operations jffs2_file_operations = |
| { |
| .llseek = generic_file_llseek, |
| .open = generic_file_open, |
| .read_iter = generic_file_read_iter, |
| .write_iter = generic_file_write_iter, |
| .unlocked_ioctl=jffs2_ioctl, |
| .mmap = generic_file_readonly_mmap, |
| .fsync = jffs2_fsync, |
| .splice_read = generic_file_splice_read, |
| }; |
| |
| /* jffs2_file_inode_operations */ |
| |
| const struct inode_operations jffs2_file_inode_operations = |
| { |
| .get_acl = jffs2_get_acl, |
| .set_acl = jffs2_set_acl, |
| .setattr = jffs2_setattr, |
| .listxattr = jffs2_listxattr, |
| }; |
| |
| const struct address_space_operations jffs2_file_address_operations = |
| { |
| .readpage = jffs2_readpage, |
| .write_begin = jffs2_write_begin, |
| .write_end = jffs2_write_end, |
| }; |
| |
| static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) |
| { |
| struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
| struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| unsigned char *pg_buf; |
| int ret; |
| |
| jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n", |
| __func__, inode->i_ino, pg->index << PAGE_SHIFT); |
| |
| BUG_ON(!PageLocked(pg)); |
| |
| pg_buf = kmap(pg); |
| /* FIXME: Can kmap fail? */ |
| |
| ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_SHIFT, |
| PAGE_SIZE); |
| |
| if (ret) { |
| ClearPageUptodate(pg); |
| SetPageError(pg); |
| } else { |
| SetPageUptodate(pg); |
| ClearPageError(pg); |
| } |
| |
| flush_dcache_page(pg); |
| kunmap(pg); |
| |
| jffs2_dbg(2, "readpage finished\n"); |
| return ret; |
| } |
| |
| int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) |
| { |
| int ret = jffs2_do_readpage_nolock(inode, pg); |
| unlock_page(pg); |
| return ret; |
| } |
| |
| |
| static int jffs2_readpage (struct file *filp, struct page *pg) |
| { |
| struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); |
| int ret; |
| |
| mutex_lock(&f->sem); |
| ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); |
| mutex_unlock(&f->sem); |
| return ret; |
| } |
| |
| static int jffs2_write_begin(struct file *filp, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| struct page *pg; |
| struct inode *inode = mapping->host; |
| struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
| struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| pgoff_t index = pos >> PAGE_SHIFT; |
| uint32_t pageofs = index << PAGE_SHIFT; |
| int ret = 0; |
| |
| jffs2_dbg(1, "%s()\n", __func__); |
| |
| if (pageofs > inode->i_size) { |
| /* Make new hole frag from old EOF to new page */ |
| struct jffs2_raw_inode ri; |
| struct jffs2_full_dnode *fn; |
| uint32_t alloc_len; |
| |
| jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", |
| (unsigned int)inode->i_size, pageofs); |
| |
| ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, |
| ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); |
| if (ret) |
| goto out_err; |
| |
| mutex_lock(&f->sem); |
| memset(&ri, 0, sizeof(ri)); |
| |
| ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); |
| ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); |
| ri.totlen = cpu_to_je32(sizeof(ri)); |
| ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); |
| |
| ri.ino = cpu_to_je32(f->inocache->ino); |
| ri.version = cpu_to_je32(++f->highest_version); |
| ri.mode = cpu_to_jemode(inode->i_mode); |
| ri.uid = cpu_to_je16(i_uid_read(inode)); |
| ri.gid = cpu_to_je16(i_gid_read(inode)); |
| ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); |
| ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); |
| ri.offset = cpu_to_je32(inode->i_size); |
| ri.dsize = cpu_to_je32(pageofs - inode->i_size); |
| ri.csize = cpu_to_je32(0); |
| ri.compr = JFFS2_COMPR_ZERO; |
| ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); |
| ri.data_crc = cpu_to_je32(0); |
| |
| fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); |
| |
| if (IS_ERR(fn)) { |
| ret = PTR_ERR(fn); |
| jffs2_complete_reservation(c); |
| mutex_unlock(&f->sem); |
| goto out_err; |
| } |
| ret = jffs2_add_full_dnode_to_inode(c, f, fn); |
| if (f->metadata) { |
| jffs2_mark_node_obsolete(c, f->metadata->raw); |
| jffs2_free_full_dnode(f->metadata); |
| f->metadata = NULL; |
| } |
| if (ret) { |
| jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", |
| ret); |
| jffs2_mark_node_obsolete(c, fn->raw); |
| jffs2_free_full_dnode(fn); |
| jffs2_complete_reservation(c); |
| mutex_unlock(&f->sem); |
| goto out_err; |
| } |
| jffs2_complete_reservation(c); |
| inode->i_size = pageofs; |
| mutex_unlock(&f->sem); |
| } |
| |
| /* |
| * While getting a page and reading data in, lock c->alloc_sem until |
| * the page is Uptodate. Otherwise GC task may attempt to read the same |
| * page in read_cache_page(), which causes a deadlock. |
| */ |
| mutex_lock(&c->alloc_sem); |
| pg = grab_cache_page_write_begin(mapping, index, flags); |
| if (!pg) { |
| ret = -ENOMEM; |
| goto release_sem; |
| } |
| *pagep = pg; |
| |
| /* |
| * Read in the page if it wasn't already present. Cannot optimize away |
| * the whole page write case until jffs2_write_end can handle the |
| * case of a short-copy. |
| */ |
| if (!PageUptodate(pg)) { |
| mutex_lock(&f->sem); |
| ret = jffs2_do_readpage_nolock(inode, pg); |
| mutex_unlock(&f->sem); |
| if (ret) { |
| unlock_page(pg); |
| put_page(pg); |
| goto release_sem; |
| } |
| } |
| jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags); |
| |
| release_sem: |
| mutex_unlock(&c->alloc_sem); |
| out_err: |
| return ret; |
| } |
| |
| static int jffs2_write_end(struct file *filp, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *pg, void *fsdata) |
| { |
| /* Actually commit the write from the page cache page we're looking at. |
| * For now, we write the full page out each time. It sucks, but it's simple |
| */ |
| struct inode *inode = mapping->host; |
| struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
| struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| struct jffs2_raw_inode *ri; |
| unsigned start = pos & (PAGE_SIZE - 1); |
| unsigned end = start + copied; |
| unsigned aligned_start = start & ~3; |
| int ret = 0; |
| uint32_t writtenlen = 0; |
| |
| jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", |
| __func__, inode->i_ino, pg->index << PAGE_SHIFT, |
| start, end, pg->flags); |
| |
| /* We need to avoid deadlock with page_cache_read() in |
| jffs2_garbage_collect_pass(). So the page must be |
| up to date to prevent page_cache_read() from trying |
| to re-lock it. */ |
| BUG_ON(!PageUptodate(pg)); |
| |
| if (end == PAGE_SIZE) { |
| /* When writing out the end of a page, write out the |
| _whole_ page. This helps to reduce the number of |
| nodes in files which have many short writes, like |
| syslog files. */ |
| aligned_start = 0; |
| } |
| |
| ri = jffs2_alloc_raw_inode(); |
| |
| if (!ri) { |
| jffs2_dbg(1, "%s(): Allocation of raw inode failed\n", |
| __func__); |
| unlock_page(pg); |
| put_page(pg); |
| return -ENOMEM; |
| } |
| |
| /* Set the fields that the generic jffs2_write_inode_range() code can't find */ |
| ri->ino = cpu_to_je32(inode->i_ino); |
| ri->mode = cpu_to_jemode(inode->i_mode); |
| ri->uid = cpu_to_je16(i_uid_read(inode)); |
| ri->gid = cpu_to_je16(i_gid_read(inode)); |
| ri->isize = cpu_to_je32((uint32_t)inode->i_size); |
| ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); |
| |
| /* In 2.4, it was already kmapped by generic_file_write(). Doesn't |
| hurt to do it again. The alternative is ifdefs, which are ugly. */ |
| kmap(pg); |
| |
| ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, |
| (pg->index << PAGE_SHIFT) + aligned_start, |
| end - aligned_start, &writtenlen); |
| |
| kunmap(pg); |
| |
| if (ret) { |
| /* There was an error writing. */ |
| SetPageError(pg); |
| } |
| |
| /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ |
| writtenlen -= min(writtenlen, (start - aligned_start)); |
| |
| if (writtenlen) { |
| if (inode->i_size < pos + writtenlen) { |
| inode->i_size = pos + writtenlen; |
| inode->i_blocks = (inode->i_size + 511) >> 9; |
| |
| inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); |
| } |
| } |
| |
| jffs2_free_raw_inode(ri); |
| |
| if (start+writtenlen < end) { |
| /* generic_file_write has written more to the page cache than we've |
| actually written to the medium. Mark the page !Uptodate so that |
| it gets reread */ |
| jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n", |
| __func__); |
| SetPageError(pg); |
| ClearPageUptodate(pg); |
| } |
| |
| jffs2_dbg(1, "%s() returning %d\n", |
| __func__, writtenlen > 0 ? writtenlen : ret); |
| unlock_page(pg); |
| put_page(pg); |
| return writtenlen > 0 ? writtenlen : ret; |
| } |