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![Arjan van de Ven](/assets/img/avatar_default.png)
Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
368 lines
7.8 KiB
C
368 lines
7.8 KiB
C
/*
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* linux/fs/ufs/namei.c
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*
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* Migration to usage of "page cache" on May 2006 by
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* Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
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*
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* Copyright (C) 1998
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* Daniel Pirkl <daniel.pirkl@email.cz>
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* Charles University, Faculty of Mathematics and Physics
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*
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* from
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*
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* linux/fs/ext2/namei.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/namei.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* Big-endian to little-endian byte-swapping/bitmaps by
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* David S. Miller (davem@caip.rutgers.edu), 1995
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*/
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/ufs_fs.h>
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#include <linux/smp_lock.h>
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#include "swab.h" /* will go away - see comment in mknod() */
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#include "util.h"
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static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
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{
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int err = ufs_add_link(dentry, inode);
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if (!err) {
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d_instantiate(dentry, inode);
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return 0;
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}
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inode_dec_link_count(inode);
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iput(inode);
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return err;
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}
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static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
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{
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struct inode * inode = NULL;
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ino_t ino;
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if (dentry->d_name.len > UFS_MAXNAMLEN)
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return ERR_PTR(-ENAMETOOLONG);
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lock_kernel();
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ino = ufs_inode_by_name(dir, dentry);
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if (ino) {
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inode = iget(dir->i_sb, ino);
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if (!inode) {
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unlock_kernel();
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return ERR_PTR(-EACCES);
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}
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}
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unlock_kernel();
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d_add(dentry, inode);
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return NULL;
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}
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/*
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* By the time this is called, we already have created
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* the directory cache entry for the new file, but it
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* is so far negative - it has no inode.
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*
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* If the create succeeds, we fill in the inode information
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* with d_instantiate().
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*/
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static int ufs_create (struct inode * dir, struct dentry * dentry, int mode,
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struct nameidata *nd)
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{
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struct inode *inode;
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int err;
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UFSD("BEGIN\n");
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inode = ufs_new_inode(dir, mode);
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err = PTR_ERR(inode);
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if (!IS_ERR(inode)) {
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inode->i_op = &ufs_file_inode_operations;
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inode->i_fop = &ufs_file_operations;
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inode->i_mapping->a_ops = &ufs_aops;
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mark_inode_dirty(inode);
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lock_kernel();
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err = ufs_add_nondir(dentry, inode);
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unlock_kernel();
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}
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UFSD("END: err=%d\n", err);
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return err;
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}
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static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
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{
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struct inode *inode;
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int err;
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if (!old_valid_dev(rdev))
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return -EINVAL;
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inode = ufs_new_inode(dir, mode);
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err = PTR_ERR(inode);
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if (!IS_ERR(inode)) {
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init_special_inode(inode, mode, rdev);
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/* NOTE: that'll go when we get wide dev_t */
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ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
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mark_inode_dirty(inode);
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lock_kernel();
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err = ufs_add_nondir(dentry, inode);
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unlock_kernel();
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}
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return err;
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}
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static int ufs_symlink (struct inode * dir, struct dentry * dentry,
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const char * symname)
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{
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struct super_block * sb = dir->i_sb;
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int err = -ENAMETOOLONG;
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unsigned l = strlen(symname)+1;
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struct inode * inode;
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if (l > sb->s_blocksize)
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goto out_notlocked;
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lock_kernel();
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inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
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err = PTR_ERR(inode);
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if (IS_ERR(inode))
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goto out;
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if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
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/* slow symlink */
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inode->i_op = &page_symlink_inode_operations;
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inode->i_mapping->a_ops = &ufs_aops;
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err = page_symlink(inode, symname, l);
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if (err)
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goto out_fail;
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} else {
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/* fast symlink */
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inode->i_op = &ufs_fast_symlink_inode_operations;
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memcpy((char*)&UFS_I(inode)->i_u1.i_data,symname,l);
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inode->i_size = l-1;
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}
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mark_inode_dirty(inode);
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err = ufs_add_nondir(dentry, inode);
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out:
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unlock_kernel();
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out_notlocked:
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return err;
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out_fail:
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inode_dec_link_count(inode);
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iput(inode);
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goto out;
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}
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static int ufs_link (struct dentry * old_dentry, struct inode * dir,
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struct dentry *dentry)
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{
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struct inode *inode = old_dentry->d_inode;
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int error;
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lock_kernel();
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if (inode->i_nlink >= UFS_LINK_MAX) {
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unlock_kernel();
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return -EMLINK;
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}
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inode->i_ctime = CURRENT_TIME_SEC;
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inode_inc_link_count(inode);
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atomic_inc(&inode->i_count);
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error = ufs_add_nondir(dentry, inode);
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unlock_kernel();
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return error;
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}
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static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
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{
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struct inode * inode;
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int err = -EMLINK;
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if (dir->i_nlink >= UFS_LINK_MAX)
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goto out;
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lock_kernel();
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inode_inc_link_count(dir);
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inode = ufs_new_inode(dir, S_IFDIR|mode);
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err = PTR_ERR(inode);
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if (IS_ERR(inode))
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goto out_dir;
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inode->i_op = &ufs_dir_inode_operations;
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inode->i_fop = &ufs_dir_operations;
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inode->i_mapping->a_ops = &ufs_aops;
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inode_inc_link_count(inode);
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err = ufs_make_empty(inode, dir);
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if (err)
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goto out_fail;
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err = ufs_add_link(dentry, inode);
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if (err)
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goto out_fail;
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unlock_kernel();
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d_instantiate(dentry, inode);
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out:
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return err;
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out_fail:
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inode_dec_link_count(inode);
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inode_dec_link_count(inode);
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iput (inode);
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out_dir:
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inode_dec_link_count(dir);
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unlock_kernel();
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goto out;
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}
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static int ufs_unlink(struct inode *dir, struct dentry *dentry)
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{
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struct inode * inode = dentry->d_inode;
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struct ufs_dir_entry *de;
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struct page *page;
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int err = -ENOENT;
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de = ufs_find_entry(dir, dentry, &page);
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if (!de)
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goto out;
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err = ufs_delete_entry(dir, de, page);
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if (err)
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goto out;
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inode->i_ctime = dir->i_ctime;
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inode_dec_link_count(inode);
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err = 0;
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out:
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return err;
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}
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static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
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{
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struct inode * inode = dentry->d_inode;
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int err= -ENOTEMPTY;
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lock_kernel();
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if (ufs_empty_dir (inode)) {
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err = ufs_unlink(dir, dentry);
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if (!err) {
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inode->i_size = 0;
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inode_dec_link_count(inode);
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inode_dec_link_count(dir);
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}
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}
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unlock_kernel();
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return err;
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}
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static int ufs_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 inode *old_inode = old_dentry->d_inode;
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struct inode *new_inode = new_dentry->d_inode;
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struct page *dir_page = NULL;
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struct ufs_dir_entry * dir_de = NULL;
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struct page *old_page;
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struct ufs_dir_entry *old_de;
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int err = -ENOENT;
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old_de = ufs_find_entry(old_dir, old_dentry, &old_page);
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if (!old_de)
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goto out;
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if (S_ISDIR(old_inode->i_mode)) {
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err = -EIO;
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dir_de = ufs_dotdot(old_inode, &dir_page);
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if (!dir_de)
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goto out_old;
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}
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if (new_inode) {
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struct page *new_page;
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struct ufs_dir_entry *new_de;
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err = -ENOTEMPTY;
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if (dir_de && !ufs_empty_dir(new_inode))
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goto out_dir;
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err = -ENOENT;
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new_de = ufs_find_entry(new_dir, new_dentry, &new_page);
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if (!new_de)
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goto out_dir;
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inode_inc_link_count(old_inode);
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ufs_set_link(new_dir, new_de, new_page, old_inode);
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new_inode->i_ctime = CURRENT_TIME_SEC;
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if (dir_de)
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drop_nlink(new_inode);
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inode_dec_link_count(new_inode);
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} else {
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if (dir_de) {
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err = -EMLINK;
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if (new_dir->i_nlink >= UFS_LINK_MAX)
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goto out_dir;
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}
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inode_inc_link_count(old_inode);
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err = ufs_add_link(new_dentry, old_inode);
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if (err) {
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inode_dec_link_count(old_inode);
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goto out_dir;
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}
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if (dir_de)
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inode_inc_link_count(new_dir);
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}
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/*
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* Like most other Unix systems, set the ctime for inodes on a
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* rename.
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* inode_dec_link_count() will mark the inode dirty.
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*/
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old_inode->i_ctime = CURRENT_TIME_SEC;
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ufs_delete_entry(old_dir, old_de, old_page);
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inode_dec_link_count(old_inode);
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if (dir_de) {
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ufs_set_link(old_inode, dir_de, dir_page, new_dir);
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inode_dec_link_count(old_dir);
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}
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return 0;
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out_dir:
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if (dir_de) {
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kunmap(dir_page);
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page_cache_release(dir_page);
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}
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out_old:
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kunmap(old_page);
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page_cache_release(old_page);
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out:
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return err;
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}
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const struct inode_operations ufs_dir_inode_operations = {
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.create = ufs_create,
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.lookup = ufs_lookup,
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.link = ufs_link,
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.unlink = ufs_unlink,
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.symlink = ufs_symlink,
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.mkdir = ufs_mkdir,
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.rmdir = ufs_rmdir,
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.mknod = ufs_mknod,
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.rename = ufs_rename,
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};
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