C++ CIFS_I函数代码示例

static void cifs_fscache_disable_inode_cookie(struct inode *inode)
{
	struct cifsInodeInfo *cifsi = CIFS_I(inode);

	if (cifsi->fscache) {
		cFYI(1, "%s: (0x%p)", __func__, cifsi->fscache);
		fscache_uncache_all_inode_pages(cifsi->fscache, inode);
		fscache_relinquish_cookie(cifsi->fscache, 1);
		cifsi->fscache = NULL;
	}
}

static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
                                   unsigned long nr_segs, loff_t pos)
{
    struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
    ssize_t written;

    written = generic_file_aio_write(iocb, iov, nr_segs, pos);
    if (!CIFS_I(inode)->clientCanCacheAll)
        filemap_fdatawrite(inode->i_mapping);
    return written;
}

/*
 * When called with struct file pointer set to NULL, there is no way we could
 * update file->private_data, but getting it stuck on openFileList provides a
 * way to access it from cifs_fill_filedata and thereby set file->private_data
 * from cifs_open.
 */
struct cifsFileInfo *
cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle,
		  struct file *file, struct vfsmount *mnt, unsigned int oflags)
{
	int oplock = 0;
	struct cifsFileInfo *pCifsFile;
	struct cifsInodeInfo *pCifsInode;
	struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);

	pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
	if (pCifsFile == NULL)
		return pCifsFile;

	if (oplockEnabled)
		oplock = REQ_OPLOCK;

	pCifsFile->netfid = fileHandle;
	pCifsFile->pid = current->tgid;
	pCifsFile->pInode = igrab(newinode);
	pCifsFile->mnt = mnt;
	pCifsFile->pfile = file;
	pCifsFile->invalidHandle = false;
	pCifsFile->closePend = false;
	mutex_init(&pCifsFile->fh_mutex);
	mutex_init(&pCifsFile->lock_mutex);
	INIT_LIST_HEAD(&pCifsFile->llist);
	atomic_set(&pCifsFile->count, 1);
	slow_work_init(&pCifsFile->oplock_break, &cifs_oplock_break_ops);

	write_lock(&GlobalSMBSeslock);
	list_add(&pCifsFile->tlist, &cifs_sb->tcon->openFileList);
	pCifsInode = CIFS_I(newinode);
	if (pCifsInode) {
		/* if readable file instance put first in list*/
		if (oflags & FMODE_READ)
			list_add(&pCifsFile->flist, &pCifsInode->openFileList);
		else
			list_add_tail(&pCifsFile->flist,
				      &pCifsInode->openFileList);

		if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
			pCifsInode->clientCanCacheAll = true;
			pCifsInode->clientCanCacheRead = true;
			cFYI(1, "Exclusive Oplock inode %p", newinode);
		} else if ((oplock & 0xF) == OPLOCK_READ)
				pCifsInode->clientCanCacheRead = true;
	}
	write_unlock(&GlobalSMBSeslock);

	file->private_data = pCifsFile;

	return pCifsFile;
}

/* Set an ACL on the server */
static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
				struct inode *inode, const char *path)
{
	struct cifsFileInfo *open_file;
	bool unlock_file = false;
	int xid;
	int rc = -EIO;
	__u16 fid;
	struct super_block *sb;
	struct cifs_sb_info *cifs_sb;

	cFYI(DBG2, ("set ACL for %s from mode 0x%x", path, inode->i_mode));

	if (!inode)
		return rc;

	sb = inode->i_sb;
	if (sb == NULL)
		return rc;

	cifs_sb = CIFS_SB(sb);
	xid = GetXid();

	open_file = find_readable_file(CIFS_I(inode));
	if (open_file) {
		unlock_file = true;
		fid = open_file->netfid;
	} else {
		int oplock = 0;
		/* open file */
		rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN,
				WRITE_DAC, 0, &fid, &oplock, NULL,
				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (rc != 0) {
			cERROR(1, ("Unable to open file to set ACL"));
			FreeXid(xid);
			return rc;
		}
	}

	rc = CIFSSMBSetCIFSACL(xid, cifs_sb->tcon, fid, pnntsd, acllen);
	cFYI(DBG2, ("SetCIFSACL rc = %d", rc));
	if (unlock_file)
		atomic_dec(&open_file->wrtPending);
	else
		CIFSSMBClose(xid, cifs_sb->tcon, fid);

	FreeXid(xid);

	return rc;
}

static int cifs_clone_file_range(struct file *src_file, loff_t off,
		struct file *dst_file, loff_t destoff, u64 len)
{
	struct inode *src_inode = file_inode(src_file);
	struct inode *target_inode = file_inode(dst_file);
	struct cifsFileInfo *smb_file_src = src_file->private_data;
	struct cifsFileInfo *smb_file_target = dst_file->private_data;
	struct cifs_tcon *target_tcon = tlink_tcon(smb_file_target->tlink);
	unsigned int xid;
	int rc;

	cifs_dbg(FYI, "clone range\n");

	xid = get_xid();

	if (!src_file->private_data || !dst_file->private_data) {
		rc = -EBADF;
		cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");
		goto out;
	}

	/*
	 * Note: cifs case is easier than btrfs since server responsible for
	 * checks for proper open modes and file type and if it wants
	 * server could even support copy of range where source = target
	 */
	lock_two_nondirectories(target_inode, src_inode);

	if (len == 0)
		len = src_inode->i_size - off;

	cifs_dbg(FYI, "about to flush pages\n");
	/* should we flush first and last page first */
	truncate_inode_pages_range(&target_inode->i_data, destoff,
				   PAGE_ALIGN(destoff + len)-1);

	if (target_tcon->ses->server->ops->duplicate_extents)
		rc = target_tcon->ses->server->ops->duplicate_extents(xid,
			smb_file_src, smb_file_target, off, len, destoff);
	else
		rc = -EOPNOTSUPP;

	/* force revalidate of size and timestamps of target file now
	   that target is updated on the server */
	CIFS_I(target_inode)->time = 0;
	/* although unlocking in the reverse order from locking is not
	   strictly necessary here it is a little cleaner to be consistent */
	unlock_two_nondirectories(src_inode, target_inode);
out:
	free_xid(xid);
	return rc;
}

int cifs_fscache_release_page(struct page *page, gfp_t gfp)
{
	if (PageFsCache(page)) {
		struct inode *inode = page->mapping->host;
		struct cifsInodeInfo *cifsi = CIFS_I(inode);

		cFYI(1, "CIFS: fscache release page (0x%p/0x%p)",
				page, cifsi->fscache);
		if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
			return 0;
	}

	return 1;
}

static ssize_t cifs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
	struct inode *inode = file_inode(iocb->ki_filp);
	struct cifsInodeInfo *cinode = CIFS_I(inode);
	ssize_t written;
	int rc;

	if (iocb->ki_filp->f_flags & O_DIRECT) {
		written = cifs_user_writev(iocb, from);
		if (written > 0 && CIFS_CACHE_READ(cinode)) {
			cifs_zap_mapping(inode);
			cifs_dbg(FYI,
				 "Set no oplock for inode=%p after a write operation\n",
				 inode);
			cinode->oplock = 0;
		}
		return written;
	}

	written = cifs_get_writer(cinode);
	if (written)
		return written;

	written = generic_file_write_iter(iocb, from);

	if (CIFS_CACHE_WRITE(CIFS_I(inode)))
		goto out;

	rc = filemap_fdatawrite(inode->i_mapping);
	if (rc)
		cifs_dbg(FYI, "cifs_file_write_iter: %d rc on %p inode\n",
			 rc, inode);

out:
	cifs_put_writer(cinode);
	return written;
}

static void
cifs_fill_fileinfo(struct inode *newinode, __u16 fileHandle,
			struct cifsTconInfo *tcon, bool write_only)
{
	int oplock = 0;
	struct cifsFileInfo *pCifsFile;
	struct cifsInodeInfo *pCifsInode;

	pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);

	if (pCifsFile == NULL)
		return;

	if (oplockEnabled)
		oplock = REQ_OPLOCK;

	pCifsFile->netfid = fileHandle;
	pCifsFile->pid = current->tgid;
	pCifsFile->pInode = newinode;
	pCifsFile->invalidHandle = false;
	pCifsFile->closePend = false;
	mutex_init(&pCifsFile->fh_mutex);
	mutex_init(&pCifsFile->lock_mutex);
	INIT_LIST_HEAD(&pCifsFile->llist);
	atomic_set(&pCifsFile->wrtPending, 0);

	/* set the following in open now
			pCifsFile->pfile = file; */
	write_lock(&GlobalSMBSeslock);
	list_add(&pCifsFile->tlist, &tcon->openFileList);
	pCifsInode = CIFS_I(newinode);
	if (pCifsInode) {
		/* if readable file instance put first in list*/
		if (write_only)
			list_add_tail(&pCifsFile->flist,
				      &pCifsInode->openFileList);
		else
			list_add(&pCifsFile->flist, &pCifsInode->openFileList);

		if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
			pCifsInode->clientCanCacheAll = true;
			pCifsInode->clientCanCacheRead = true;
			cFYI(1, ("Exclusive Oplock inode %p", newinode));
		} else if ((oplock & 0xF) == OPLOCK_READ)
				pCifsInode->clientCanCacheRead = true;
	}
	write_unlock(&GlobalSMBSeslock);
}

static struct dentry *
cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
		    struct cifs_fattr *fattr)
{
	struct dentry *dentry, *alias;
	struct inode *inode;
	struct super_block *sb = parent->d_inode->i_sb;

	cFYI(1, "For %s", name->name);

	if (parent->d_op && parent->d_op->d_hash)
		parent->d_op->d_hash(parent, parent->d_inode, name);
	else
		name->hash = full_name_hash(name->name, name->len);

	dentry = d_lookup(parent, name);
	if (dentry) {
		
		inode = dentry->d_inode;
		/* update inode in place if i_ino didn't change */
		if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
			cifs_fattr_to_inode(inode, fattr);
 			return dentry;
		}
		d_drop(dentry);
		dput(dentry);
	}

	dentry = d_alloc(parent, name);
	if (dentry == NULL)
		return NULL;

	inode = cifs_iget(sb, fattr);
	if (!inode) {
		dput(dentry);
		return NULL;
	}

	alias = d_materialise_unique(dentry, inode);
	if (alias != NULL) {
		dput(dentry);
		if (IS_ERR(alias))
			return NULL;
		dentry = alias;
	}

	return dentry;
}

static void cifs_fscache_enable_inode_cookie(struct inode *inode)
{
	struct cifsInodeInfo *cifsi = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *tcon = cifs_sb_master_tcon(cifs_sb);

	if (cifsi->fscache)
		return;

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE) {
		cifsi->fscache = fscache_acquire_cookie(tcon->fscache,
				&cifs_fscache_inode_object_def, cifsi);
		cFYI(1, "CIFS: got FH cookie (0x%p/0x%p)", tcon->fscache,
				cifsi->fscache);
	}
}

/* Retrieve an ACL from the server */
static struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
				      struct inode *inode, const char *path,
				      u32 *pacllen)
{
	struct cifs_ntsd *pntsd = NULL;
	struct cifsFileInfo *open_file = NULL;

	if (inode)
		open_file = find_readable_file(CIFS_I(inode));
	if (!open_file)
		return get_cifs_acl_by_path(cifs_sb, path, pacllen);

	pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->netfid, pacllen);
	cifsFileInfo_put(open_file);
	return pntsd;
}

/* Set an ACL on the server */
static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
				struct inode *inode, const char *path)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsFileInfo *open_file;
	int rc;

	cFYI(DBG2, "set ACL for %s from mode 0x%x", path, inode->i_mode);

	open_file = find_readable_file(CIFS_I(inode));
	if (!open_file)
		return set_cifs_acl_by_path(cifs_sb, path, pnntsd, acllen);

	rc = set_cifs_acl_by_fid(cifs_sb, open_file->netfid, pnntsd, acllen);
	cifsFileInfo_put(open_file);
	return rc;
}

static loff_t cifs_llseek(struct file *file, loff_t offset, int origin)
{
    /* origin == SEEK_END => we must revalidate the cached file length */
    if (origin == SEEK_END) {
        int retval;

        /* some applications poll for the file length in this strange
           way so we must seek to end on non-oplocked files by
           setting the revalidate time to zero */
        CIFS_I(file->f_path.dentry->d_inode)->time = 0;

        retval = cifs_revalidate_file(file);
        if (retval < 0)
            return (loff_t)retval;
    }
    return generic_file_llseek_unlocked(file, offset, origin);
}

void cifs_fscache_reset_inode_cookie(struct inode *inode)
{
	struct cifsInodeInfo *cifsi = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct fscache_cookie *old = cifsi->fscache;

	if (cifsi->fscache) {
		/* retire the current fscache cache and get a new one */
		fscache_relinquish_cookie(cifsi->fscache, 1);

		cifsi->fscache = fscache_acquire_cookie(
					cifs_sb_master_tcon(cifs_sb)->fscache,
					&cifs_fscache_inode_object_def,
					cifsi);
		cFYI(1, "CIFS: new cookie 0x%p oldcookie 0x%p",
				cifsi->fscache, old);
	}
}

static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
				   unsigned long nr_segs, loff_t pos)
{
	struct inode *inode = file_inode(iocb->ki_filp);
	ssize_t written;
	int rc;

	written = generic_file_aio_write(iocb, iov, nr_segs, pos);

	if (CIFS_I(inode)->clientCanCacheAll)
		return written;

	rc = filemap_fdatawrite(inode->i_mapping);
	if (rc)
		cFYI(1, "cifs_file_aio_write: %d rc on %p inode", rc, inode);

	return written;
}