514d748f69
Commite4502c63f5
(ufs: deal with nfsd/iget races) made ufs create inodes with I_NEW flag set. However ufs_mkdir() never cleared this flag. Thus if someone ever tried to lookup the directory by inode number, he would deadlock waiting for I_NEW to be cleared. Luckily this mostly happens only if the filesystem is exported over NFS since otherwise we have the inode attached to dentry and don't look it up by inode number. In rare cases dentry can get freed without inode being freed and then we'd hit the deadlock even without NFS export. Fix the problem by clearing I_NEW before instantiating new directory inode. Fixes:e4502c63f5
Reported-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
357 lines
7.5 KiB
C
357 lines
7.5 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 "ufs_fs.h"
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#include "ufs.h"
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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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unlock_new_inode(inode);
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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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unlock_new_inode(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, unsigned int flags)
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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_ufs(dir->i_sb);
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ino = ufs_inode_by_name(dir, &dentry->d_name);
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if (ino)
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inode = ufs_iget(dir->i_sb, ino);
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unlock_ufs(dir->i_sb);
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return d_splice_alias(inode, dentry);
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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, umode_t mode,
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bool excl)
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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_ufs(dir->i_sb);
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err = ufs_add_nondir(dentry, inode);
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unlock_ufs(dir->i_sb);
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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, umode_t 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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ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev);
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mark_inode_dirty(inode);
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lock_ufs(dir->i_sb);
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err = ufs_add_nondir(dentry, inode);
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unlock_ufs(dir->i_sb);
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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_ufs(dir->i_sb);
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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 = &ufs_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(UFS_I(inode)->i_u1.i_symlink, 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_ufs(dir->i_sb);
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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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unlock_new_inode(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 = d_inode(old_dentry);
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int error;
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lock_ufs(dir->i_sb);
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inode->i_ctime = CURRENT_TIME_SEC;
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inode_inc_link_count(inode);
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ihold(inode);
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error = ufs_add_link(dentry, inode);
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if (error) {
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inode_dec_link_count(inode);
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iput(inode);
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} else
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d_instantiate(dentry, inode);
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unlock_ufs(dir->i_sb);
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return error;
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}
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static int ufs_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 err;
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lock_ufs(dir->i_sb);
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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_ufs(dir->i_sb);
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unlock_new_inode(inode);
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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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unlock_new_inode(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_ufs(dir->i_sb);
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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 = d_inode(dentry);
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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->d_name, &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 = d_inode(dentry);
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int err= -ENOTEMPTY;
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lock_ufs(dir->i_sb);
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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_ufs(dir->i_sb);
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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 = d_inode(old_dentry);
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struct inode *new_inode = d_inode(new_dentry);
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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->d_name, &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->d_name, &new_page);
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if (!new_de)
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goto out_dir;
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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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err = ufs_add_link(new_dentry, old_inode);
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if (err)
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goto out_dir;
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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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*/
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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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mark_inode_dirty(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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