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Diffstat (limited to 'fs/freevxfs/vxfs_immed.c')
-rw-r--r-- | fs/freevxfs/vxfs_immed.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/fs/freevxfs/vxfs_immed.c b/fs/freevxfs/vxfs_immed.c new file mode 100644 index 000000000..8b9229e2c --- /dev/null +++ b/fs/freevxfs/vxfs_immed.c @@ -0,0 +1,115 @@ +/* + * Copyright (c) 2000-2001 Christoph Hellwig. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL"). + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Veritas filesystem driver - support for 'immed' inodes. + */ +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/namei.h> + +#include "vxfs.h" +#include "vxfs_extern.h" +#include "vxfs_inode.h" + + +static void * vxfs_immed_follow_link(struct dentry *, struct nameidata *); + +static int vxfs_immed_readpage(struct file *, struct page *); + +/* + * Inode operations for immed symlinks. + * + * Unliked all other operations we do not go through the pagecache, + * but do all work directly on the inode. + */ +const struct inode_operations vxfs_immed_symlink_iops = { + .readlink = generic_readlink, + .follow_link = vxfs_immed_follow_link, +}; + +/* + * Address space operations for immed files and directories. + */ +const struct address_space_operations vxfs_immed_aops = { + .readpage = vxfs_immed_readpage, +}; + +/** + * vxfs_immed_follow_link - follow immed symlink + * @dp: dentry for the link + * @np: pathname lookup data for the current path walk + * + * Description: + * vxfs_immed_follow_link restarts the pathname lookup with + * the data obtained from @dp. + * + * Returns: + * Zero on success, else a negative error code. + */ +static void * +vxfs_immed_follow_link(struct dentry *dp, struct nameidata *np) +{ + struct vxfs_inode_info *vip = VXFS_INO(d_inode(dp)); + nd_set_link(np, vip->vii_immed.vi_immed); + return NULL; +} + +/** + * vxfs_immed_readpage - read part of an immed inode into pagecache + * @file: file context (unused) + * @page: page frame to fill in. + * + * Description: + * vxfs_immed_readpage reads a part of the immed area of the + * file that hosts @pp into the pagecache. + * + * Returns: + * Zero on success, else a negative error code. + * + * Locking status: + * @page is locked and will be unlocked. + */ +static int +vxfs_immed_readpage(struct file *fp, struct page *pp) +{ + struct vxfs_inode_info *vip = VXFS_INO(pp->mapping->host); + u_int64_t offset = (u_int64_t)pp->index << PAGE_CACHE_SHIFT; + caddr_t kaddr; + + kaddr = kmap(pp); + memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_CACHE_SIZE); + kunmap(pp); + + flush_dcache_page(pp); + SetPageUptodate(pp); + unlock_page(pp); + + return 0; +} |