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-rw-r--r--fs/autofs/root.c564
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 = &current->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;
+ }
+}