/* -*- linux-c -*- --------------------------------------------------------- * * * linux/fs/autofs/root.c * * Copyright 1997 Transmeta Corporation -- All Rights Reserved * * This file is part of the Linux kernel and is made available under * the terms of the GNU General Public License, version 2, or at your * option, any later version, incorporated herein by reference. * * ------------------------------------------------------------------------- */ #include #include #include #include "autofs_i.h" static int autofs_root_readdir(struct file *,void *,filldir_t); static int autofs_root_lookup(struct inode *,struct dentry *); static int autofs_root_symlink(struct inode *,struct dentry *,const char *); static int autofs_root_unlink(struct inode *,struct dentry *); static int autofs_root_rmdir(struct inode *,struct dentry *); static int autofs_root_mkdir(struct inode *,struct dentry *,int); static int autofs_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long); static struct file_operations autofs_root_operations = { NULL, /* llseek */ NULL, /* read */ NULL, /* write */ autofs_root_readdir, /* readdir */ NULL, /* poll */ autofs_root_ioctl, /* ioctl */ NULL, /* mmap */ NULL, /* open */ NULL, /* release */ NULL, /* fsync */ NULL, /* fasync */ NULL, /* check_media_change */ NULL, /* revalidate */ NULL /* lock */ }; struct inode_operations autofs_root_inode_operations = { &autofs_root_operations, /* file operations */ NULL, /* create */ autofs_root_lookup, /* lookup */ NULL, /* link */ autofs_root_unlink, /* unlink */ autofs_root_symlink, /* symlink */ autofs_root_mkdir, /* mkdir */ autofs_root_rmdir, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL, /* permission */ NULL, /* smap */ NULL, /* updatepage */ NULL /* revalidate */ }; static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir) { struct autofs_dir_ent *ent; struct autofs_dirhash *dirhash; struct inode * inode = filp->f_dentry->d_inode; off_t onr, nr; if (!inode || !S_ISDIR(inode->i_mode)) return -ENOTDIR; dirhash = &((struct autofs_sb_info *)inode->i_sb->u.generic_sbp)->dirhash; nr = filp->f_pos; switch(nr) { case 0: if (filldir(dirent, ".", 1, nr, inode->i_ino) < 0) return 0; filp->f_pos = ++nr; /* fall through */ case 1: if (filldir(dirent, "..", 2, nr, inode->i_ino) < 0) return 0; filp->f_pos = ++nr; /* fall through */ default: while ( onr = nr, ent = autofs_hash_enum(dirhash,&nr) ) { if (filldir(dirent,ent->name,ent->len,onr,ent->ino) < 0) return 0; filp->f_pos = nr; } break; } return 0; } static int try_to_fill_dentry(struct dentry * dentry, struct super_block * sb, struct autofs_sb_info *sbi) { struct inode * inode; struct autofs_dir_ent *ent; while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) { int status = autofs_wait(sbi, &dentry->d_name); /* Turn this into a real negative dentry? */ if (status == -ENOENT) { dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT; dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; return 1; } else if (status) { /* Return a negative dentry, but leave it "pending" */ return 1; } } /* Abuse this field as a pointer to the directory entry, used to find the expire list pointers */ dentry->d_time = (unsigned long) ent; if (!dentry->d_inode) { inode = iget(sb, ent->ino); if (!inode) { /* Failed, but leave pending for next time */ return 1; } dentry->d_inode = inode; } if (S_ISDIR(dentry->d_inode->i_mode)) { while (dentry == dentry->d_mounts) schedule(); } autofs_update_usage(&sbi->dirhash,ent); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; return 1; } /* * Revalidate is called on every cache lookup. Some of those * cache lookups may actually happen while the dentry is not * yet completely filled in, and revalidate has to delay such * lookups.. */ static int autofs_revalidate(struct dentry * dentry) { struct autofs_sb_info *sbi; struct inode * dir = dentry->d_parent->d_inode; struct autofs_dir_ent *ent; sbi = (struct autofs_sb_info *) dir->i_sb->u.generic_sbp; /* Pending dentry */ if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { if (autofs_oz_mode(sbi)) return 1; return try_to_fill_dentry(dentry, dir->i_sb, sbi); } /* Negative dentry.. invalidate if "old" */ if (!dentry->d_inode) return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT); /* Update the usage list */ ent = (struct autofs_dir_ent *) dentry->d_time; autofs_update_usage(&sbi->dirhash,ent); return 1; } static struct dentry_operations autofs_dentry_operations = { autofs_revalidate, NULL, /* d_hash */ NULL, /* d_compare */ }; static int autofs_root_lookup(struct inode *dir, struct dentry * dentry) { struct autofs_sb_info *sbi; struct inode *res; int oz_mode; DPRINTK(("autofs_root_lookup: name = ")); autofs_say(dentry->d_name.name,dentry->d_name.len); if (!S_ISDIR(dir->i_mode)) return -ENOTDIR; res = NULL; sbi = (struct autofs_sb_info *) dir->i_sb->u.generic_sbp; oz_mode = autofs_oz_mode(sbi); DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n", current->pid, current->pgrp, sbi->catatonic, oz_mode)); /* * Mark the dentry incomplete, but add it. This is needed so * that the VFS layer knows about the dentry, and we can count * on catching any lookups through the revalidate. * * Let all the hard work be done by the revalidate function that * needs to be able to do this anyway.. * * We need to do this before we release the directory semaphore. */ dentry->d_op = &autofs_dentry_operations; dentry->d_flags |= DCACHE_AUTOFS_PENDING; d_add(dentry, NULL); up(&dir->i_sem); autofs_revalidate(dentry); down(&dir->i_sem); /* * If we are still pending, check if we had to handle * a signal. If so we can force a restart.. */ if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { if (signal_pending(current)) return -ERESTARTNOINTR; } return 0; } static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct autofs_sb_info *sbi = (struct autofs_sb_info *) dir->i_sb->u.generic_sbp; struct autofs_dirhash *dh = &sbi->dirhash; struct autofs_dir_ent *ent; unsigned int n; int slsize; struct autofs_symlink *sl; DPRINTK(("autofs_root_symlink: %s <- ", symname)); autofs_say(dentry->d_name.name,dentry->d_name.len); if ( !autofs_oz_mode(sbi) ) return -EPERM; if ( autofs_hash_lookup(dh, &dentry->d_name) ) return -EEXIST; n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS); if ( n >= AUTOFS_MAX_SYMLINKS ) return -ENOSPC; set_bit(n,sbi->symlink_bitmap); sl = &sbi->symlink[n]; sl->len = strlen(symname); sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL); if ( !sl->data ) { clear_bit(n,sbi->symlink_bitmap); return -ENOSPC; } ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL); if ( !ent ) { kfree(sl->data); clear_bit(n,sbi->symlink_bitmap); return -ENOSPC; } ent->name = kmalloc(dentry->d_name.len, GFP_KERNEL); if ( !ent->name ) { kfree(sl->data); kfree(ent); clear_bit(n,sbi->symlink_bitmap); return -ENOSPC; } memcpy(sl->data,symname,slsize); sl->mtime = CURRENT_TIME; ent->ino = AUTOFS_FIRST_SYMLINK + n; ent->hash = dentry->d_name.hash; memcpy(ent->name, dentry->d_name.name,ent->len = dentry->d_name.len); autofs_hash_insert(dh,ent); d_instantiate(dentry, iget(dir->i_sb,ent->ino)); return 0; } /* * NOTE! * * Normal filesystems would do a "d_delete()" to tell the VFS dcache * that the file no longer exists. However, doing that means that the * VFS layer can turn the dentry into a negative dentry, which we * obviously do not want (we're dropping the entry not because it * doesn't exist, but because it has timed out). * * Also see autofs_root_rmdir().. */ static int autofs_root_unlink(struct inode *dir, struct dentry *dentry) { struct autofs_sb_info *sbi = (struct autofs_sb_info *) dir->i_sb->u.generic_sbp; struct autofs_dirhash *dh = &sbi->dirhash; struct autofs_dir_ent *ent; unsigned int n; if ( !autofs_oz_mode(sbi) ) return -EPERM; ent = autofs_hash_lookup(dh, &dentry->d_name); if ( !ent ) return -ENOENT; n = ent->ino - AUTOFS_FIRST_SYMLINK; if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap) ) return -EINVAL; /* Not a symlink inode, can't unlink */ autofs_hash_delete(ent); clear_bit(n,sbi->symlink_bitmap); kfree(sbi->symlink[n].data); d_drop(dentry); return 0; } static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry) { struct autofs_sb_info *sbi = (struct autofs_sb_info *) dir->i_sb->u.generic_sbp; struct autofs_dirhash *dh = &sbi->dirhash; struct autofs_dir_ent *ent; if ( !autofs_oz_mode(sbi) ) return -EPERM; ent = autofs_hash_lookup(dh, &dentry->d_name); if ( !ent ) return -ENOENT; if ( (unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO ) return -ENOTDIR; /* Not a directory */ autofs_hash_delete(ent); dir->i_nlink--; d_drop(dentry); return 0; } static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode) { struct autofs_sb_info *sbi = (struct autofs_sb_info *) dir->i_sb->u.generic_sbp; struct autofs_dirhash *dh = &sbi->dirhash; struct autofs_dir_ent *ent; if ( !autofs_oz_mode(sbi) ) return -EPERM; ent = autofs_hash_lookup(dh, &dentry->d_name); if ( ent ) return -EEXIST; if ( sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO ) { printk("autofs: Out of inode numbers -- what the heck did you do??\n"); return -ENOSPC; } ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL); if ( !ent ) return -ENOSPC; ent->name = kmalloc(dentry->d_name.len, GFP_KERNEL); if ( !ent->name ) { kfree(ent); return -ENOSPC; } ent->hash = dentry->d_name.hash; memcpy(ent->name, dentry->d_name.name, ent->len = dentry->d_name.len); ent->ino = sbi->next_dir_ino++; autofs_hash_insert(dh,ent); dir->i_nlink++; d_instantiate(dentry, iget(dir->i_sb,ent->ino)); return 0; } /* Get/set timeout ioctl() operation */ static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi, unsigned long *p) { int rv; unsigned long ntimeout; if ( (rv = get_user(ntimeout, p)) || (rv = put_user(sbi->exp_timeout/HZ, p)) ) return rv; if ( ntimeout > ULONG_MAX/HZ ) sbi->exp_timeout = 0; else sbi->exp_timeout = ntimeout * HZ; return 0; } /* Return protocol version */ static inline int autofs_get_protover(int *p) { return put_user(AUTOFS_PROTO_VERSION, p); } /* Perform an expiry operation */ static inline int autofs_expire_run(struct autofs_sb_info *sbi, struct autofs_packet_expire *pkt_p) { struct autofs_dir_ent *ent; struct autofs_packet_expire pkt; struct autofs_dirhash *dh = &(sbi->dirhash); memset(&pkt,0,sizeof pkt); pkt.hdr.proto_version = AUTOFS_PROTO_VERSION; pkt.hdr.type = autofs_ptype_expire; if ( !sbi->exp_timeout || !(ent = autofs_expire(dh,sbi->exp_timeout)) ) return -EAGAIN; pkt.len = ent->len; memcpy(pkt.name, ent->name, pkt.len); pkt.name[pkt.len] = '\0'; if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) ) return -EFAULT; autofs_update_usage(dh,ent); return 0; } /* * ioctl()'s on the root directory is the chief method for the daemon to * generate kernel reactions */ static int autofs_root_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { struct autofs_sb_info *sbi = (struct autofs_sb_info *)inode->i_sb->u.generic_sbp; DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,current->pgrp)); if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT ) return -ENOTTY; if ( !autofs_oz_mode(sbi) && !fsuser() ) return -EPERM; switch(cmd) { case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ return autofs_wait_release(sbi,arg,0); case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ return autofs_wait_release(sbi,arg,-ENOENT); case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ autofs_catatonic_mode(sbi); return 0; case AUTOFS_IOC_PROTOVER: /* Get protocol version */ return autofs_get_protover((int *)arg); case AUTOFS_IOC_SETTIMEOUT: return autofs_get_set_timeout(sbi,(unsigned long *)arg); case AUTOFS_IOC_EXPIRE: return autofs_expire_run(sbi,(struct autofs_packet_expire *)arg); default: return -ENOSYS; } }