diff options
| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/autofs/root.c | |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/autofs/root.c')
| -rw-r--r-- | fs/autofs/root.c | 564 | 
1 files changed, 564 insertions, 0 deletions
| diff --git a/fs/autofs/root.c b/fs/autofs/root.c new file mode 100644 index 000000000000..a1ab1c0ed215 --- /dev/null +++ b/fs/autofs/root.c @@ -0,0 +1,564 @@ +/* -*- linux-c -*- --------------------------------------------------------- * + * + * linux/fs/autofs/root.c + * + *  Copyright 1997-1998 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 <linux/errno.h> +#include <linux/stat.h> +#include <linux/param.h> +#include <linux/time.h> +#include <linux/smp_lock.h> +#include "autofs_i.h" + +static int autofs_root_readdir(struct file *,void *,filldir_t); +static struct dentry *autofs_root_lookup(struct inode *,struct dentry *, struct nameidata *); +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); + +struct file_operations autofs_root_operations = { +	.read		= generic_read_dir, +	.readdir	= autofs_root_readdir, +	.ioctl		= autofs_root_ioctl, +}; + +struct inode_operations autofs_root_inode_operations = { +        .lookup		= autofs_root_lookup, +        .unlink		= autofs_root_unlink, +        .symlink	= autofs_root_symlink, +        .mkdir		= autofs_root_mkdir, +        .rmdir		= autofs_root_rmdir, +}; + +static int autofs_root_readdir(struct file *filp, void *dirent, filldir_t filldir) +{ +	struct autofs_dir_ent *ent = NULL; +	struct autofs_dirhash *dirhash; +	struct autofs_sb_info *sbi; +	struct inode * inode = filp->f_dentry->d_inode; +	off_t onr, nr; + +	lock_kernel(); + +	sbi = autofs_sbi(inode->i_sb); +	dirhash = &sbi->dirhash; +	nr = filp->f_pos; + +	switch(nr) +	{ +	case 0: +		if (filldir(dirent, ".", 1, nr, inode->i_ino, DT_DIR) < 0) +			goto out; +		filp->f_pos = ++nr; +		/* fall through */ +	case 1: +		if (filldir(dirent, "..", 2, nr, inode->i_ino, DT_DIR) < 0) +			goto out; +		filp->f_pos = ++nr; +		/* fall through */ +	default: +		while ( onr = nr, ent = autofs_hash_enum(dirhash,&nr,ent) ) { +			if ( !ent->dentry || d_mountpoint(ent->dentry) ) { +				if (filldir(dirent,ent->name,ent->len,onr,ent->ino,DT_UNKNOWN) < 0) +					goto out; +				filp->f_pos = nr; +			} +		} +		break; +	} + +out: +	unlock_kernel(); +	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; +	int status = 0; + +	if ( !(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) ) { +		do { +			if ( status && dentry->d_inode ) { +				if ( status != -ENOENT ) +					printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name); +				return 0; /* Try to get the kernel to invalidate this dentry */ +			} + +			/* 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; +			} +			status = autofs_wait(sbi, &dentry->d_name); +		} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)) ); +	} + +	/* 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 this is a directory that isn't a mount point, bitch at the +	   daemon and fix it in user space */ +	if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) { +		return !autofs_wait(sbi, &dentry->d_name); +	} + +	/* We don't update the usages for the autofs daemon itself, this +	   is necessary for recursive autofs mounts */ +	if ( !autofs_oz_mode(sbi) ) { +		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 nameidata *nd) +{ +	struct inode * dir; +	struct autofs_sb_info *sbi; +	struct autofs_dir_ent *ent; +	int res; + +	lock_kernel(); +	dir = dentry->d_parent->d_inode; +	sbi = autofs_sbi(dir->i_sb); + +	/* Pending dentry */ +	if ( dentry->d_flags & DCACHE_AUTOFS_PENDING ) { +		if (autofs_oz_mode(sbi)) +			res = 1; +		else +			res = try_to_fill_dentry(dentry, dir->i_sb, sbi); +		unlock_kernel(); +		return res; +	} + +	/* Negative dentry.. invalidate if "old" */ +	if (!dentry->d_inode) { +		unlock_kernel(); +		return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT); +	} +		 +	/* Check for a non-mountpoint directory */ +	if ( S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) ) { +		if (autofs_oz_mode(sbi)) +			res = 1; +		else +			res = try_to_fill_dentry(dentry, dir->i_sb, sbi); +		unlock_kernel(); +		return res; +	} + +	/* Update the usage list */ +	if ( !autofs_oz_mode(sbi) ) { +		ent = (struct autofs_dir_ent *) dentry->d_time; +		if ( ent ) +			autofs_update_usage(&sbi->dirhash,ent); +	} +	unlock_kernel(); +	return 1; +} + +static struct dentry_operations autofs_dentry_operations = { +	.d_revalidate	= autofs_revalidate, +}; + +static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) +{ +	struct autofs_sb_info *sbi; +	int oz_mode; + +	DPRINTK(("autofs_root_lookup: name = ")); +	lock_kernel(); +	autofs_say(dentry->d_name.name,dentry->d_name.len); + +	if (dentry->d_name.len > NAME_MAX) { +		unlock_kernel(); +		return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */ +	} + +	sbi = autofs_sbi(dir->i_sb); + +	oz_mode = autofs_oz_mode(sbi); +	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n", +		 current->pid, process_group(current), 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, nd); +	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) { +		/* See if we were interrupted */ +		if (signal_pending(current)) { +			sigset_t *sigset = ¤t->pending.signal; +			if (sigismember (sigset, SIGKILL) || +			    sigismember (sigset, SIGQUIT) || +			    sigismember (sigset, SIGINT)) { +				unlock_kernel(); +				return ERR_PTR(-ERESTARTNOINTR); +			} +		} +	} +	unlock_kernel(); + +	/* +	 * If this dentry is unhashed, then we shouldn't honour this +	 * lookup even if the dentry is positive.  Returning ENOENT here +	 * doesn't do the right thing for all system calls, but it should +	 * be OK for the operations we permit from an autofs. +	 */ +	if ( dentry->d_inode && d_unhashed(dentry) ) +		return ERR_PTR(-ENOENT); + +	return NULL; +} + +static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname) +{ +	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); +	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); + +	lock_kernel(); +	if ( !autofs_oz_mode(sbi) ) { +		unlock_kernel(); +		return -EACCES; +	} + +	if ( autofs_hash_lookup(dh, &dentry->d_name) ) { +		unlock_kernel(); +		return -EEXIST; +	} + +	n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS); +	if ( n >= AUTOFS_MAX_SYMLINKS ) { +		unlock_kernel(); +		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); +		unlock_kernel(); +		return -ENOSPC; +	} + +	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL); +	if ( !ent ) { +		kfree(sl->data); +		clear_bit(n,sbi->symlink_bitmap); +		unlock_kernel(); +		return -ENOSPC; +	} + +	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL); +	if ( !ent->name ) { +		kfree(sl->data); +		kfree(ent); +		clear_bit(n,sbi->symlink_bitmap); +		unlock_kernel(); +		return -ENOSPC; +	} + +	memcpy(sl->data,symname,slsize); +	sl->mtime = get_seconds(); + +	ent->ino = AUTOFS_FIRST_SYMLINK + n; +	ent->hash = dentry->d_name.hash; +	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len)); +	ent->dentry = NULL;	/* We don't keep the dentry for symlinks */ + +	autofs_hash_insert(dh,ent); +	d_instantiate(dentry, iget(dir->i_sb,ent->ino)); +	unlock_kernel(); +	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 = autofs_sbi(dir->i_sb); +	struct autofs_dirhash *dh = &sbi->dirhash; +	struct autofs_dir_ent *ent; +	unsigned int n; + +	/* This allows root to remove symlinks */ +	lock_kernel(); +	if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) { +		unlock_kernel(); +		return -EACCES; +	} + +	ent = autofs_hash_lookup(dh, &dentry->d_name); +	if ( !ent ) { +		unlock_kernel(); +		return -ENOENT; +	} + +	n = ent->ino - AUTOFS_FIRST_SYMLINK; +	if ( n >= AUTOFS_MAX_SYMLINKS ) { +		unlock_kernel(); +		return -EISDIR;	/* It's a directory, dummy */ +	} +	if ( !test_bit(n,sbi->symlink_bitmap) ) { +		unlock_kernel(); +		return -EINVAL;	/* Nonexistent symlink?  Shouldn't happen */ +	} +	 +	dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL; +	autofs_hash_delete(ent); +	clear_bit(n,sbi->symlink_bitmap); +	kfree(sbi->symlink[n].data); +	d_drop(dentry); +	 +	unlock_kernel(); +	return 0; +} + +static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry) +{ +	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); +	struct autofs_dirhash *dh = &sbi->dirhash; +	struct autofs_dir_ent *ent; + +	lock_kernel(); +	if ( !autofs_oz_mode(sbi) ) { +		unlock_kernel(); +		return -EACCES; +	} + +	ent = autofs_hash_lookup(dh, &dentry->d_name); +	if ( !ent ) { +		unlock_kernel(); +		return -ENOENT; +	} + +	if ( (unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO ) { +		unlock_kernel(); +		return -ENOTDIR; /* Not a directory */ +	} + +	if ( ent->dentry != dentry ) { +		printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name); +	} + +	dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL; +	autofs_hash_delete(ent); +	dir->i_nlink--; +	d_drop(dentry); +	unlock_kernel(); + +	return 0; +} + +static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ +	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); +	struct autofs_dirhash *dh = &sbi->dirhash; +	struct autofs_dir_ent *ent; +	ino_t ino; + +	lock_kernel(); +	if ( !autofs_oz_mode(sbi) ) { +		unlock_kernel(); +		return -EACCES; +	} + +	ent = autofs_hash_lookup(dh, &dentry->d_name); +	if ( ent ) { +		unlock_kernel(); +		return -EEXIST; +	} + +	if ( sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO ) { +		printk("autofs: Out of inode numbers -- what the heck did you do??\n"); +		unlock_kernel(); +		return -ENOSPC; +	} +	ino = sbi->next_dir_ino++; + +	ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL); +	if ( !ent ) { +		unlock_kernel(); +		return -ENOSPC; +	} + +	ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL); +	if ( !ent->name ) { +		kfree(ent); +		unlock_kernel(); +		return -ENOSPC; +	} + +	ent->hash = dentry->d_name.hash; +	memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len)); +	ent->ino = ino; +	ent->dentry = dentry; +	autofs_hash_insert(dh,ent); + +	dir->i_nlink++; +	d_instantiate(dentry, iget(dir->i_sb,ino)); +	unlock_kernel(); + +	return 0; +} + +/* Get/set timeout ioctl() operation */ +static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi, +					 unsigned long __user *p) +{ +	unsigned long ntimeout; + +	if (get_user(ntimeout, p) || +	    put_user(sbi->exp_timeout / HZ, p)) +		return -EFAULT; + +	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 __user *p) +{ +	return put_user(AUTOFS_PROTO_VERSION, p); +} + +/* Perform an expiry operation */ +static inline int autofs_expire_run(struct super_block *sb, +				    struct autofs_sb_info *sbi, +				    struct vfsmount *mnt, +				    struct autofs_packet_expire __user *pkt_p) +{ +	struct autofs_dir_ent *ent; +	struct autofs_packet_expire pkt; + +	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(sb,sbi,mnt)) ) +		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; + +	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 = autofs_sbi(inode->i_sb); +	void __user *argp = (void __user *)arg; + +	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,process_group(current))); + +	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) && !capable(CAP_SYS_ADMIN) ) +		return -EPERM; +	 +	switch(cmd) { +	case AUTOFS_IOC_READY:	/* Wait queue: go ahead and retry */ +		return autofs_wait_release(sbi,(autofs_wqt_t)arg,0); +	case AUTOFS_IOC_FAIL:	/* Wait queue: fail with ENOENT */ +		return autofs_wait_release(sbi,(autofs_wqt_t)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(argp); +	case AUTOFS_IOC_SETTIMEOUT: +		return autofs_get_set_timeout(sbi, argp); +	case AUTOFS_IOC_EXPIRE: +		return autofs_expire_run(inode->i_sb, sbi, filp->f_vfsmnt, +					 argp); +	default: +		return -ENOSYS; +	} +} | 
