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freebsd/sys/ufs/ifs/ifs_vnops.c
Adrian Chadd 0b0c10b48d Initial commit of IFS - a inode-namespaced FFS. Here is a short
description:

How it works:
--

Basically ifs is a copy of ffs, overriding some vfs/vnops. (Yes, hack.)
I didn't see the need in duplicating all of sys/ufs/ffs to get this
off the ground.

File creation is done through a special file - 'newfile' . When newfile
is called, the system allocates and returns an inode. Note that newfile
is done in a cloning fashion:

fd = open("newfile", O_CREAT|O_RDWR, 0644);
fstat(fd, &st);

printf("new file is %d\n", (int)st.st_ino);

Once you have created a file, you can open() and unlink() it by its returned
inode number retrieved from the stat call, ie:

fd = open("5", O_RDWR);

The creation permissions depend entirely if you have write access to the
root directory of the filesystem.

To get the list of currently allocated inodes, VOP_READDIR has been added
which returns a directory listing of those currently allocated.

--

What this entails:

* patching conf/files and conf/options to include IFS as a new compile
  option (and since ifs depends upon FFS, include the FFS routines)

* An entry in i386/conf/NOTES indicating IFS exists and where to go for
  an explanation

* Unstaticize a couple of routines in src/sys/ufs/ffs/ which the IFS
  routines require (ffs_mount() and ffs_reload())

* a new bunch of routines in src/sys/ufs/ifs/ which implement the IFS
  routines. IFS replaces some of the vfsops, and a handful of vnops -
  most notably are VFS_VGET(), VOP_LOOKUP(), VOP_UNLINK() and VOP_READDIR().
  Any other directory operation is marked as invalid.

What this results in:

* an IFS partition's create permissions are controlled by the perm/ownership of
  the root mount point, just like a normal directory

* Each inode has perm and ownership too

* IFS does *NOT* mean an FFS partition can be opened per inode. This is a
  completely seperate filesystem here

* Softupdates doesn't work with IFS, and really I don't think it needs it.
  Besides, fsck's are FAST. (Try it :-)

* Inodes 0 and 1 aren't allocatable because they are special (dump/swap IIRC).
  Inode 2 isn't allocatable since UFS/FFS locks all inodes in the system against
  this particular inode, and unravelling THAT code isn't trivial. Therefore,
  useful inodes start at 3.

Enjoy, and feedback is definitely appreciated!
2000-10-14 03:02:30 +00:00

474 lines
12 KiB
C

/*
* Copyright (c) 1999, 2000
* Adrian Chadd <adrian@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ffs_vnops.c 8.15 (Berkeley) 5/14/95
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/conf.h>
#include <sys/poll.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <machine/limits.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/vm_zone.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ufs/dir.h>
#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>
#include <ufs/ifs/ifs_extern.h>
/* IFS debugging */
#undef DEBUG_IFS_READDIR
/* Declare our trampling into the FFS code */
extern int ffs_fsync (struct vop_fsync_args *);
static int ffs_getpages(struct vop_getpages_args *);
static int ffs_putpages(struct vop_putpages_args *);
static int ffs_read(struct vop_read_args *);
static int ffs_write(struct vop_write_args *);
static int ifs_noop(struct vop_generic_args *);
static int ifs_getattr(struct vop_getattr_args *);
static int ifs_create(struct vop_create_args *);
static int ifs_makeinode(int mode, struct vnode *, struct vnode **,
struct componentname *);
static int ifs_remove(struct vop_remove_args *);
static int ifs_readdir(struct vop_readdir_args *);
static int ifs_dirremove(struct vnode *, struct inode *, int, int);
/* Global vfs data structures for ifs. */
vop_t **ifs_vnodeop_p;
static struct vnodeopv_entry_desc ifs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) ufs_vnoperate },
{ &vop_fsync_desc, (vop_t *) ffs_fsync },
{ &vop_getpages_desc, (vop_t *) ffs_getpages },
{ &vop_putpages_desc, (vop_t *) ffs_putpages },
{ &vop_read_desc, (vop_t *) ffs_read },
{ &vop_balloc_desc, (vop_t *) ffs_balloc },
{ &vop_reallocblks_desc, (vop_t *) ffs_reallocblks },
{ &vop_write_desc, (vop_t *) ffs_write },
{ &vop_lookup_desc, (vop_t *) ifs_lookup },
{ &vop_getattr_desc, (vop_t *) ifs_getattr },
{ &vop_create_desc, (vop_t *) ifs_create },
{ &vop_remove_desc, (vop_t *) ifs_remove },
{ &vop_readdir_desc, (vop_t *) ifs_readdir },
/* NULL operations for ifs */
{ &vop_cachedlookup_desc, (vop_t *) ifs_noop },
{ &vop_mkdir_desc, (vop_t *) ifs_noop },
{ &vop_mknod_desc, (vop_t *) ifs_noop },
{ &vop_readlink_desc, (vop_t *) ifs_noop },
{ &vop_rename_desc, (vop_t *) ifs_noop },
{ &vop_rmdir_desc, (vop_t *) ifs_noop },
{ &vop_symlink_desc, (vop_t *) ifs_noop },
{ &vop_link_desc, (vop_t *) ifs_noop },
{ &vop_whiteout_desc, (vop_t *) ifs_noop },
{ NULL, NULL }
};
static struct vnodeopv_desc ifs_vnodeop_opv_desc =
{ &ifs_vnodeop_p, ifs_vnodeop_entries };
vop_t **ifs_specop_p;
static struct vnodeopv_entry_desc ifs_specop_entries[] = {
{ &vop_default_desc, (vop_t *) ufs_vnoperatespec },
{ &vop_fsync_desc, (vop_t *) ffs_fsync },
{ NULL, NULL }
};
static struct vnodeopv_desc ifs_specop_opv_desc =
{ &ifs_specop_p, ifs_specop_entries };
vop_t **ifs_fifoop_p;
static struct vnodeopv_entry_desc ifs_fifoop_entries[] = {
{ &vop_default_desc, (vop_t *) ufs_vnoperatefifo },
{ &vop_fsync_desc, (vop_t *) ffs_fsync },
{ NULL, NULL }
};
static struct vnodeopv_desc ifs_fifoop_opv_desc =
{ &ifs_fifoop_p, ifs_fifoop_entries };
VNODEOP_SET(ifs_vnodeop_opv_desc);
VNODEOP_SET(ifs_specop_opv_desc);
VNODEOP_SET(ifs_fifoop_opv_desc);
#include <ufs/ufs/ufs_readwrite.c>
static int
ifs_noop(ap)
struct vop_generic_args *ap;
{
return EOPNOTSUPP;
}
/* ARGSUSED */
static int
ifs_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
register struct vnode *vp = ap->a_vp;
register struct inode *ip = VTOI(vp);
register struct vattr *vap = ap->a_vap;
ufs_itimes(vp);
/*
* Copy from inode table
*/
vap->va_fsid = dev2udev(ip->i_dev);
vap->va_fileid = ip->i_number;
vap->va_mode = ip->i_mode & ~IFMT;
vap->va_nlink = VFSTOUFS(vp->v_mount)->um_i_effnlink_valid ?
ip->i_effnlink : ip->i_nlink;
vap->va_uid = ip->i_uid;
vap->va_gid = ip->i_gid;
vap->va_rdev = ip->i_rdev;
vap->va_size = ip->i_din.di_size;
vap->va_atime.tv_sec = ip->i_atime;
vap->va_atime.tv_nsec = ip->i_atimensec;
vap->va_mtime.tv_sec = ip->i_mtime;
vap->va_mtime.tv_nsec = ip->i_mtimensec;
vap->va_ctime.tv_sec = ip->i_ctime;
vap->va_ctime.tv_nsec = ip->i_ctimensec;
vap->va_flags = ip->i_flags;
vap->va_gen = ip->i_gen;
vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
vap->va_type = IFTOVT(ip->i_mode);
vap->va_filerev = ip->i_modrev;
return (0);
}
/*
* Create a regular file
*/
int
ifs_create(ap)
struct vop_create_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
} */ *ap;
{
int error;
error =
ifs_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
ap->a_dvp, ap->a_vpp, ap->a_cnp);
if (error)
return (error);
VN_POLLEVENT(ap->a_dvp, POLLWRITE);
return (0);
}
/*
* Allocate a new inode.
*/
int
ifs_makeinode(mode, dvp, vpp, cnp)
int mode;
struct vnode *dvp;
struct vnode **vpp;
struct componentname *cnp;
{
register struct inode *ip, *pdir;
struct vnode *tvp;
int error;
pdir = VTOI(dvp);
#ifdef DIAGNOSTIC
if ((cnp->cn_flags & HASBUF) == 0)
panic("ifs_makeinode: no name");
#endif
*vpp = NULL;
if ((mode & IFMT) == 0)
mode |= IFREG;
error = UFS_VALLOC(dvp, mode, cnp->cn_cred, &tvp);
if (error) {
zfree(namei_zone, cnp->cn_pnbuf);
return (error);
}
ip = VTOI(tvp);
ip->i_gid = pdir->i_gid;
ip->i_uid = cnp->cn_cred->cr_uid;
#ifdef QUOTA
if ((error = getinoquota(ip)) ||
(error = chkiq(ip, 1, cnp->cn_cred, 0))) {
UFS_VFREE(tvp, ip->i_number, mode);
vput(tvp);
return (error);
}
#endif
ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
ip->i_mode = mode;
tvp->v_type = IFTOVT(mode); /* Rest init'd in getnewvnode(). */
ip->i_effnlink = 1;
ip->i_nlink = 1;
if (DOINGSOFTDEP(tvp))
softdep_change_linkcnt(ip);
if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred) &&
suser_xxx(cnp->cn_cred, 0, 0))
ip->i_mode &= ~ISGID;
if (cnp->cn_flags & ISWHITEOUT)
ip->i_flags |= UF_OPAQUE;
/*
* Make sure inode goes to disk before directory entry.
*/
error = UFS_UPDATE(tvp, !(DOINGSOFTDEP(tvp) | DOINGASYNC(tvp)));
if (error)
goto bad;
*vpp = tvp;
return (0);
bad:
/*
* Write error occurred trying to update the inode
* or the directory so must deallocate the inode.
*/
ip->i_effnlink = 0;
ip->i_nlink = 0;
ip->i_flag |= IN_CHANGE;
if (DOINGSOFTDEP(tvp))
softdep_change_linkcnt(ip);
vput(tvp);
return (error);
}
int
ifs_remove(ap)
struct vop_remove_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
struct inode *ip;
struct vnode *vp = ap->a_vp;
struct vnode *dvp = ap->a_dvp;
int error;
ip = VTOI(vp);
if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
(VTOI(dvp)->i_flags & APPEND)) {
error = EPERM;
goto out;
}
error = ifs_dirremove(dvp, ip, ap->a_cnp->cn_flags, 0);
VN_POLLEVENT(vp, POLLNLINK);
out:
return (error);
}
/*
* highly cutdown ufs_dirremove, since we're not updating
* any directory entries. :-)
*/
static int
ifs_dirremove(struct vnode *dvp, struct inode *ip, int flags, int isrmdir)
{
int error;
if (ip) {
ip->i_effnlink--;
ip->i_flag |= IN_CHANGE;
ip->i_nlink--;
error = 0;
} else
error = ENOENT;
return (error);
}
/*
* ifs_readdir
*
* Do the directory listing, representing the allocated inodes
* making up this filesystem.
*
*/
static int
ifs_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
int *ncookies;
u_long **a_cookies;
} */ *ap;
{
int inodenum;
struct dirent *dent, *lastdp = NULL;
struct dirent *tmpdp;
char *dirbuf;
struct inode *ip = VTOI(ap->a_vp); /* To get the mount info later */
struct mount *mp = ap->a_vp->v_mount;
struct fs *fs = VFSTOUFS(mp)->um_fs;
int maxnuminode = fs->fs_ncg * fs->fs_ipg;
int error = 0;
int count;
int dircount = 0;
int copylen = 0;
char iret;
/*
* Get the offset, which represents the inode we're going to
* start from
*/
inodenum = ap->a_uio->uio_offset;
#ifdef DEBUG_IFS_READDIR
printf("ifs_readdir: starting with inode %d\n", inodenum);
#endif
if (inodenum < 0)
return EINVAL;
/*
* Next, get the buffer size, round it down to a dirent, and
* figure out how many allocated inodes we need to match
*/
count = ap->a_uio->uio_resid;
/*
* Next, create a dirbuf to fill with directory entries
*/
MALLOC(tmpdp, struct dirent *, sizeof (struct dirent), M_TEMP, M_WAITOK);
MALLOC(dirbuf, char *, count, M_TEMP, M_WAITOK);
dent = (struct dirent *)dirbuf;
/* now, keep reading until we run out of inodes */
while (inodenum <= maxnuminode) {
/* Get bitmap info and see if we bother with this cg */
iret = ifs_isinodealloc(ip, inodenum);
if (iret == IFS_INODE_EMPTYCG) {
/* Skip this CG */
/* Next cg please */
inodenum -= inodenum % fs->fs_ipg;
inodenum += fs->fs_ipg;
continue;
}
/* Allocated and not special? */
if ((inodenum > 2) && iret == IFS_INODE_ISALLOC) {
/* Create a new entry */
sprintf(tmpdp->d_name, "%d", inodenum);
tmpdp->d_fileno = inodenum;
tmpdp->d_type = DT_REG;
tmpdp->d_namlen = strlen(tmpdp->d_name);
tmpdp->d_reclen = DIRECTSIZ(tmpdp->d_namlen);
/* Make sure we have enough space for this entry */
if (tmpdp->d_reclen > count)
break;
/* Copy it to the given buffer */
bcopy(tmpdp, dent, tmpdp->d_reclen);
/* Decrement the count */
count -= dent->d_reclen;
copylen += dent->d_reclen;
lastdp = dent;
/* Increment the offset pointer */
dent = (struct dirent *)((char *)dent + dent->d_reclen);
dircount++;
}
/* Increment the inode number we are checking */
inodenum++;
}
/* End */
#ifdef DEBUG_IFS_READDIR
printf("ifs_readdir: copied %d directories\n", dircount);
#endif
/*
* Get the last dent updated, and make the record d_reclen last the whole
* buffer.
*/
if (lastdp != NULL) {
/* Update the length of the last entry */
lastdp->d_reclen += count;
}
/* Copy the data out */
#ifdef DEBUG_IFS_READDIR
printf("ifs_readdir: copied %d bytes\n", copylen);
#endif
error = uiomove(dirbuf, copylen, ap->a_uio);
/* Free memory we've used */
FREE(dirbuf, M_TEMP);
FREE(tmpdp, M_TEMP);
/* Set uio_offset to the last inode number */
ap->a_uio->uio_offset = inodenum;
/* Handle EOF/eofflag */
if ((inodenum >= maxnuminode) && (ap->a_eofflag != NULL)) {
*ap->a_eofflag = 1;
#ifdef DEBUG_IFS_READDIR
printf("ifs_readdir: setting EOF flag\n");
#endif
}
#ifdef DEBUG_IFS_READDIR
printf("ifs_readdir: new offset: %d\n", inodenum);
#endif
return error;
}