Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  *  linux/fs/nfs/symlink.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *  Copyright (C) 1992  Rick Sladkey
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  *  Optimization changes Copyright (C) 1994 Florian La Roche
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  *  Jun 7 1999, cache symlink lookups in the page cache.  -DaveM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  *  nfs symlink handling code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/time.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/sunrpc/clnt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/nfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/nfs2.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/nfs_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /* Symlink caching in the page cache is even more simplistic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  * and straight-forward than readdir caching.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) static int nfs_symlink_filler(void *data, struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	struct inode *inode = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	if (error < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 		goto error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	SetPageUptodate(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) error:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	SetPageError(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static const char *nfs_get_link(struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 				struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 				struct delayed_call *done)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	struct page *page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	void *err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	if (!dentry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		err = ERR_PTR(nfs_revalidate_mapping_rcu(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 		page = find_get_page(inode->i_mapping, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		if (!page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 			return ERR_PTR(-ECHILD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 		if (!PageUptodate(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 			put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 			return ERR_PTR(-ECHILD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 		err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 		if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 		page = read_cache_page(&inode->i_data, 0, nfs_symlink_filler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 				inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 		if (IS_ERR(page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 			return ERR_CAST(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 	set_delayed_call(done, page_put_link, page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 	return page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)  * symlinks can't do much...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) const struct inode_operations nfs_symlink_inode_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 	.get_link	= nfs_get_link,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 	.getattr	= nfs_getattr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 	.setattr	= nfs_setattr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) };