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![Al Viro](/assets/img/avatar_default.png)
Making something exportable takes more than providing ->s_export_ops.
In particular, ->lookup() *MUST* use d_splice_alias() instead of
d_add().
Reading Documentation/filesystems/nfs/Exporting would've been a good idea;
as it is, exporting AFFS is badly (and exploitably) broken.
Partially-Fixes: ed4433d723
"fs/affs: make affs exportable"
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
579 lines
13 KiB
C
579 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/affs/namei.c
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*
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* (c) 1996 Hans-Joachim Widmaier - Rewritten
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*
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* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
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*
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* (C) 1991 Linus Torvalds - minix filesystem
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*/
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#include "affs.h"
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#include <linux/exportfs.h>
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typedef int (*toupper_t)(int);
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/* Simple toupper() for DOS\1 */
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static int
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affs_toupper(int ch)
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{
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return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
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}
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/* International toupper() for DOS\3 ("international") */
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static int
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affs_intl_toupper(int ch)
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{
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return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
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&& ch <= 0xFE && ch != 0xF7) ?
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ch - ('a' - 'A') : ch;
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}
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static inline toupper_t
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affs_get_toupper(struct super_block *sb)
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{
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return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ?
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affs_intl_toupper : affs_toupper;
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}
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/*
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* Note: the dentry argument is the parent dentry.
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*/
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static inline int
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__affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t toupper, bool notruncate)
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{
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const u8 *name = qstr->name;
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unsigned long hash;
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int retval;
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u32 len;
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retval = affs_check_name(qstr->name, qstr->len, notruncate);
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if (retval)
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return retval;
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hash = init_name_hash(dentry);
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len = min(qstr->len, AFFSNAMEMAX);
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for (; len > 0; name++, len--)
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hash = partial_name_hash(toupper(*name), hash);
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qstr->hash = end_name_hash(hash);
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return 0;
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}
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static int
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affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
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{
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return __affs_hash_dentry(dentry, qstr, affs_toupper,
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affs_nofilenametruncate(dentry));
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}
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static int
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affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
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{
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return __affs_hash_dentry(dentry, qstr, affs_intl_toupper,
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affs_nofilenametruncate(dentry));
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}
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static inline int __affs_compare_dentry(unsigned int len,
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const char *str, const struct qstr *name, toupper_t toupper,
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bool notruncate)
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{
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const u8 *aname = str;
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const u8 *bname = name->name;
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/*
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* 'str' is the name of an already existing dentry, so the name
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* must be valid. 'name' must be validated first.
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*/
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if (affs_check_name(name->name, name->len, notruncate))
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return 1;
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/*
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* If the names are longer than the allowed 30 chars,
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* the excess is ignored, so their length may differ.
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*/
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if (len >= AFFSNAMEMAX) {
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if (name->len < AFFSNAMEMAX)
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return 1;
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len = AFFSNAMEMAX;
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} else if (len != name->len)
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return 1;
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for (; len > 0; len--)
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if (toupper(*aname++) != toupper(*bname++))
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return 1;
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return 0;
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}
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static int
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affs_compare_dentry(const struct dentry *dentry,
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unsigned int len, const char *str, const struct qstr *name)
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{
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return __affs_compare_dentry(len, str, name, affs_toupper,
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affs_nofilenametruncate(dentry));
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}
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static int
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affs_intl_compare_dentry(const struct dentry *dentry,
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unsigned int len, const char *str, const struct qstr *name)
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{
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return __affs_compare_dentry(len, str, name, affs_intl_toupper,
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affs_nofilenametruncate(dentry));
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}
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/*
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* NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
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*/
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static inline int
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affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
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{
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const u8 *name = dentry->d_name.name;
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int len = dentry->d_name.len;
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if (len >= AFFSNAMEMAX) {
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if (*name2 < AFFSNAMEMAX)
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return 0;
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len = AFFSNAMEMAX;
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} else if (len != *name2)
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return 0;
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for (name2++; len > 0; len--)
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if (toupper(*name++) != toupper(*name2++))
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return 0;
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return 1;
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}
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int
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affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
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{
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toupper_t toupper = affs_get_toupper(sb);
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u32 hash;
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hash = len = min(len, AFFSNAMEMAX);
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for (; len > 0; len--)
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hash = (hash * 13 + toupper(*name++)) & 0x7ff;
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return hash % AFFS_SB(sb)->s_hashsize;
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}
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static struct buffer_head *
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affs_find_entry(struct inode *dir, struct dentry *dentry)
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{
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struct super_block *sb = dir->i_sb;
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struct buffer_head *bh;
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toupper_t toupper = affs_get_toupper(sb);
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u32 key;
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pr_debug("%s(\"%pd\")\n", __func__, dentry);
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bh = affs_bread(sb, dir->i_ino);
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if (!bh)
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return ERR_PTR(-EIO);
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key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
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for (;;) {
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affs_brelse(bh);
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if (key == 0)
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return NULL;
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bh = affs_bread(sb, key);
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if (!bh)
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return ERR_PTR(-EIO);
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if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
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return bh;
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key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
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}
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}
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struct dentry *
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affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
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{
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struct super_block *sb = dir->i_sb;
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struct buffer_head *bh;
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struct inode *inode = NULL;
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struct dentry *res;
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pr_debug("%s(\"%pd\")\n", __func__, dentry);
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affs_lock_dir(dir);
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bh = affs_find_entry(dir, dentry);
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if (IS_ERR(bh)) {
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affs_unlock_dir(dir);
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return ERR_CAST(bh);
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}
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if (bh) {
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u32 ino = bh->b_blocknr;
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/* store the real header ino in d_fsdata for faster lookups */
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dentry->d_fsdata = (void *)(long)ino;
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switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
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//link to dirs disabled
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//case ST_LINKDIR:
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case ST_LINKFILE:
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ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
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}
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affs_brelse(bh);
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inode = affs_iget(sb, ino);
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}
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res = d_splice_alias(inode, dentry);
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if (!IS_ERR_OR_NULL(res))
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res->d_fsdata = dentry->d_fsdata;
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affs_unlock_dir(dir);
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return res;
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}
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int
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affs_unlink(struct inode *dir, struct dentry *dentry)
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{
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pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
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d_inode(dentry)->i_ino, dentry);
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return affs_remove_header(dentry);
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}
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int
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affs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
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{
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struct super_block *sb = dir->i_sb;
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struct inode *inode;
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int error;
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pr_debug("%s(%lu,\"%pd\",0%ho)\n",
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__func__, dir->i_ino, dentry, mode);
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inode = affs_new_inode(dir);
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if (!inode)
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return -ENOSPC;
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inode->i_mode = mode;
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affs_mode_to_prot(inode);
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mark_inode_dirty(inode);
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inode->i_op = &affs_file_inode_operations;
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inode->i_fop = &affs_file_operations;
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inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ?
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&affs_aops_ofs : &affs_aops;
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error = affs_add_entry(dir, inode, dentry, ST_FILE);
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if (error) {
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clear_nlink(inode);
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iput(inode);
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return error;
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}
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return 0;
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}
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int
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affs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
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{
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struct inode *inode;
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int error;
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pr_debug("%s(%lu,\"%pd\",0%ho)\n",
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__func__, dir->i_ino, dentry, mode);
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inode = affs_new_inode(dir);
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if (!inode)
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return -ENOSPC;
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inode->i_mode = S_IFDIR | mode;
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affs_mode_to_prot(inode);
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inode->i_op = &affs_dir_inode_operations;
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inode->i_fop = &affs_dir_operations;
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error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
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if (error) {
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clear_nlink(inode);
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mark_inode_dirty(inode);
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iput(inode);
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return error;
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}
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return 0;
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}
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int
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affs_rmdir(struct inode *dir, struct dentry *dentry)
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{
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pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
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d_inode(dentry)->i_ino, dentry);
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return affs_remove_header(dentry);
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}
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int
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affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
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{
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struct super_block *sb = dir->i_sb;
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struct buffer_head *bh;
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struct inode *inode;
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char *p;
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int i, maxlen, error;
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char c, lc;
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pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n",
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__func__, dir->i_ino, dentry, symname);
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maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
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inode = affs_new_inode(dir);
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if (!inode)
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return -ENOSPC;
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inode->i_op = &affs_symlink_inode_operations;
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inode_nohighmem(inode);
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inode->i_data.a_ops = &affs_symlink_aops;
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inode->i_mode = S_IFLNK | 0777;
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affs_mode_to_prot(inode);
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error = -EIO;
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bh = affs_bread(sb, inode->i_ino);
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if (!bh)
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goto err;
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i = 0;
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p = (char *)AFFS_HEAD(bh)->table;
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lc = '/';
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if (*symname == '/') {
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struct affs_sb_info *sbi = AFFS_SB(sb);
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while (*symname == '/')
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symname++;
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spin_lock(&sbi->symlink_lock);
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while (sbi->s_volume[i]) /* Cannot overflow */
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*p++ = sbi->s_volume[i++];
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spin_unlock(&sbi->symlink_lock);
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}
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while (i < maxlen && (c = *symname++)) {
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if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
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*p++ = '/';
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i++;
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symname += 2;
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lc = '/';
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} else if (c == '.' && lc == '/' && *symname == '/') {
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symname++;
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lc = '/';
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} else {
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*p++ = c;
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lc = c;
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i++;
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}
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if (lc == '/')
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while (*symname == '/')
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symname++;
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}
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*p = 0;
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inode->i_size = i + 1;
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mark_buffer_dirty_inode(bh, inode);
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affs_brelse(bh);
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mark_inode_dirty(inode);
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error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
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if (error)
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goto err;
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return 0;
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err:
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clear_nlink(inode);
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mark_inode_dirty(inode);
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iput(inode);
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return error;
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}
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int
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affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
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{
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struct inode *inode = d_inode(old_dentry);
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pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
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dentry);
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return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
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}
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static int
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affs_rename(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry)
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{
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struct super_block *sb = old_dir->i_sb;
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struct buffer_head *bh = NULL;
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int retval;
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retval = affs_check_name(new_dentry->d_name.name,
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new_dentry->d_name.len,
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affs_nofilenametruncate(old_dentry));
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if (retval)
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return retval;
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/* Unlink destination if it already exists */
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if (d_really_is_positive(new_dentry)) {
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retval = affs_remove_header(new_dentry);
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if (retval)
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return retval;
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}
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bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
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if (!bh)
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return -EIO;
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|
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/* Remove header from its parent directory. */
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affs_lock_dir(old_dir);
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retval = affs_remove_hash(old_dir, bh);
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affs_unlock_dir(old_dir);
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if (retval)
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goto done;
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/* And insert it into the new directory with the new name. */
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affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
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affs_fix_checksum(sb, bh);
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affs_lock_dir(new_dir);
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retval = affs_insert_hash(new_dir, bh);
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affs_unlock_dir(new_dir);
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/* TODO: move it back to old_dir, if error? */
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done:
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mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
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affs_brelse(bh);
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return retval;
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}
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|
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static int
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affs_xrename(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry)
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{
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|
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struct super_block *sb = old_dir->i_sb;
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struct buffer_head *bh_old = NULL;
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struct buffer_head *bh_new = NULL;
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int retval;
|
|
|
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bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino);
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if (!bh_old)
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return -EIO;
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|
|
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bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
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if (!bh_new)
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return -EIO;
|
|
|
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/* Remove old header from its parent directory. */
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affs_lock_dir(old_dir);
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retval = affs_remove_hash(old_dir, bh_old);
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affs_unlock_dir(old_dir);
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if (retval)
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goto done;
|
|
|
|
/* Remove new header from its parent directory. */
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affs_lock_dir(new_dir);
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|
retval = affs_remove_hash(new_dir, bh_new);
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affs_unlock_dir(new_dir);
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|
if (retval)
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goto done;
|
|
|
|
/* Insert old into the new directory with the new name. */
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affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry);
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affs_fix_checksum(sb, bh_old);
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affs_lock_dir(new_dir);
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retval = affs_insert_hash(new_dir, bh_old);
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affs_unlock_dir(new_dir);
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/* Insert new into the old directory with the old name. */
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affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry);
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affs_fix_checksum(sb, bh_new);
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affs_lock_dir(old_dir);
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retval = affs_insert_hash(old_dir, bh_new);
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affs_unlock_dir(old_dir);
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done:
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mark_buffer_dirty_inode(bh_old, new_dir);
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mark_buffer_dirty_inode(bh_new, old_dir);
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affs_brelse(bh_old);
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affs_brelse(bh_new);
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return retval;
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}
|
|
|
|
int affs_rename2(struct inode *old_dir, struct dentry *old_dentry,
|
|
struct inode *new_dir, struct dentry *new_dentry,
|
|
unsigned int flags)
|
|
{
|
|
|
|
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
|
|
return -EINVAL;
|
|
|
|
pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__,
|
|
old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
|
|
|
|
if (flags & RENAME_EXCHANGE)
|
|
return affs_xrename(old_dir, old_dentry, new_dir, new_dentry);
|
|
|
|
return affs_rename(old_dir, old_dentry, new_dir, new_dentry);
|
|
}
|
|
|
|
static struct dentry *affs_get_parent(struct dentry *child)
|
|
{
|
|
struct inode *parent;
|
|
struct buffer_head *bh;
|
|
|
|
bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
|
|
if (!bh)
|
|
return ERR_PTR(-EIO);
|
|
|
|
parent = affs_iget(child->d_sb,
|
|
be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
|
|
brelse(bh);
|
|
if (IS_ERR(parent))
|
|
return ERR_CAST(parent);
|
|
|
|
return d_obtain_alias(parent);
|
|
}
|
|
|
|
static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
|
|
u32 generation)
|
|
{
|
|
struct inode *inode;
|
|
|
|
if (!affs_validblock(sb, ino))
|
|
return ERR_PTR(-ESTALE);
|
|
|
|
inode = affs_iget(sb, ino);
|
|
if (IS_ERR(inode))
|
|
return ERR_CAST(inode);
|
|
|
|
return inode;
|
|
}
|
|
|
|
static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
|
|
int fh_len, int fh_type)
|
|
{
|
|
return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
|
|
affs_nfs_get_inode);
|
|
}
|
|
|
|
static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
|
|
int fh_len, int fh_type)
|
|
{
|
|
return generic_fh_to_parent(sb, fid, fh_len, fh_type,
|
|
affs_nfs_get_inode);
|
|
}
|
|
|
|
const struct export_operations affs_export_ops = {
|
|
.fh_to_dentry = affs_fh_to_dentry,
|
|
.fh_to_parent = affs_fh_to_parent,
|
|
.get_parent = affs_get_parent,
|
|
};
|
|
|
|
const struct dentry_operations affs_dentry_operations = {
|
|
.d_hash = affs_hash_dentry,
|
|
.d_compare = affs_compare_dentry,
|
|
};
|
|
|
|
const struct dentry_operations affs_intl_dentry_operations = {
|
|
.d_hash = affs_intl_hash_dentry,
|
|
.d_compare = affs_intl_compare_dentry,
|
|
};
|