diff options
Diffstat (limited to 'kernel/fs/jffs2/file.c')
| -rw-r--r-- | kernel/fs/jffs2/file.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/kernel/fs/jffs2/file.c b/kernel/fs/jffs2/file.c new file mode 100644 index 000000000..f509f62e1 --- /dev/null +++ b/kernel/fs/jffs2/file.c @@ -0,0 +1,337 @@ +/* + * 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; + + mutex_lock(&inode->i_mutex); + /* Trigger GC to flush any pending writes for this inode */ + jffs2_flush_wbuf_gc(c, inode->i_ino); + mutex_unlock(&inode->i_mutex); + + 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, + .setxattr = jffs2_setxattr, + .getxattr = jffs2_getxattr, + .listxattr = jffs2_listxattr, + .removexattr = jffs2_removexattr +}; + +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_CACHE_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_CACHE_SHIFT, PAGE_CACHE_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); + struct jffs2_raw_inode ri; + uint32_t alloc_len = 0; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + uint32_t pageofs = index << PAGE_CACHE_SHIFT; + int ret = 0; + + jffs2_dbg(1, "%s()\n", __func__); + + if (pageofs > inode->i_size) { + ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, + ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); + if (ret) + return ret; + } + + mutex_lock(&f->sem); + pg = grab_cache_page_write_begin(mapping, index, flags); + if (!pg) { + if (alloc_len) + jffs2_complete_reservation(c); + mutex_unlock(&f->sem); + return -ENOMEM; + } + *pagep = pg; + + if (alloc_len) { + /* Make new hole frag from old EOF to new page */ + struct jffs2_full_dnode *fn; + + jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", + (unsigned int)inode->i_size, pageofs); + + 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); + goto out_page; + } + 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); + goto out_page; + } + jffs2_complete_reservation(c); + inode->i_size = pageofs; + } + + /* + * 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)) { + ret = jffs2_do_readpage_nolock(inode, pg); + if (ret) + goto out_page; + } + mutex_unlock(&f->sem); + jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags); + return ret; + +out_page: + unlock_page(pg); + page_cache_release(pg); + mutex_unlock(&f->sem); + 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_CACHE_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_CACHE_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_CACHE_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); + page_cache_release(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_CACHE_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); + page_cache_release(pg); + return writtenlen > 0 ? writtenlen : ret; +} |