/*
* ulfs_read_dotdot: Store in *ino_ret the inode number of the parent
* of the directory vp.
*/
static int
ulfs_read_dotdot(struct vnode *vp, kauth_cred_t cred, ino_t *ino_ret)
{
struct lfs_dirtemplate dirbuf;
int error;
KASSERT(vp != NULL);
KASSERT(ino_ret != NULL);
KASSERT(vp->v_type == VDIR);
error = vn_rdwr(UIO_READ, vp, &dirbuf, sizeof dirbuf, (off_t)0,
UIO_SYSSPACE, IO_NODELOCKED, cred, NULL, NULL);
if (error)
return error;
if (ulfs_dirbuf_dotdot_namlen(&dirbuf, vp) != 2 ||
dirbuf.dotdot_name[0] != '.' ||
dirbuf.dotdot_name[1] != '.')
/* XXX Panic? Print warning? */
return ENOTDIR;
*ino_ret = ulfs_rw32(dirbuf.dotdot_ino,
ULFS_IPNEEDSWAP(VTOI(vp)));
return 0;
}
/*
* ulfs_direct_namlen: Return the namlen of the directory entry ep from
* the directory vp.
*/
static int /* XXX int? uint8_t? */
ulfs_direct_namlen(const struct lfs_direct *ep, const struct vnode *vp)
{
bool swap;
KASSERT(ep != NULL);
KASSERT(vp != NULL);
KASSERT(VTOI(vp) != NULL);
KASSERT(VTOI(vp)->i_ump != NULL);
#if (BYTE_ORDER == LITTLE_ENDIAN)
swap = (ULFS_IPNEEDSWAP(VTOI(vp)) == 0);
#else
swap = (ULFS_IPNEEDSWAP(VTOI(vp)) != 0);
#endif
return ((FSFMT(vp) && swap)? ep->d_type : ep->d_namlen);
}
/*
* ulfs_dirbuf_dotdot_namlen: Return the namlen of the directory buffer
* dirbuf that came from the directory vp. Swap byte order if
* necessary.
*/
static int /* XXX int? uint8_t? */
ulfs_dirbuf_dotdot_namlen(const struct lfs_dirtemplate *dirbuf,
const struct vnode *vp)
{
bool swap;
KASSERT(dirbuf != NULL);
KASSERT(vp != NULL);
KASSERT(VTOI(vp) != NULL);
KASSERT(VTOI(vp)->i_ump != NULL);
#if (BYTE_ORDER == LITTLE_ENDIAN)
swap = (ULFS_IPNEEDSWAP(VTOI(vp)) == 0);
#else
swap = (ULFS_IPNEEDSWAP(VTOI(vp)) != 0);
#endif
return ((FSFMT(vp) && swap)?
dirbuf->dotdot_type : dirbuf->dotdot_namlen);
}
/*
* Write a directory entry after a call to namei, using the parameters
* that ulfs_lookup left in nameidata and in the ulfs_lookup_results.
*
* DVP is the directory to be updated. It must be locked.
* ULR is the ulfs_lookup_results structure from the final lookup step.
* TVP is not used. (XXX: why is it here? remove it)
* DIRP is the new directory entry contents.
* CNP is the componentname from the final lookup step.
* NEWDIRBP is not used and (XXX) should be removed. The previous
* comment here said it was used by the now-removed softupdates code.
*
* The link count of the target inode is *not* incremented; the
* caller does that.
*
* If ulr->ulr_count is 0, ulfs_lookup did not find space to insert the
* directory entry. ulr_offset, which is the place to put the entry,
* should be on a block boundary (and should be at the end of the
* directory AFAIK) and a fresh block is allocated to put the new
* directory entry in.
*
* If ulr->ulr_count is not zero, ulfs_lookup found a slot to insert
* the entry into. This slot ranges from ulr_offset to ulr_offset +
* ulr_count. However, this slot may already be partially populated
* requiring compaction. See notes below.
*
* Furthermore, if ulr_count is not zero and ulr_endoff is not the
* same as i_size, the directory is truncated to size ulr_endoff.
*/
int
ulfs_direnter(struct vnode *dvp, const struct ulfs_lookup_results *ulr,
struct vnode *tvp, struct lfs_direct *dirp,
struct componentname *cnp, struct buf *newdirbp)
{
kauth_cred_t cr;
int newentrysize;
struct inode *dp;
struct buf *bp;
u_int dsize;
struct lfs_direct *ep, *nep;
int error, ret, lfs_blkoff, loc, spacefree;
char *dirbuf;
struct timespec ts;
struct ulfsmount *ump = VFSTOULFS(dvp->v_mount);
struct lfs *fs = ump->um_lfs;
const int needswap = ULFS_MPNEEDSWAP(fs);
int dirblksiz = fs->um_dirblksiz;
error = 0;
cr = cnp->cn_cred;
dp = VTOI(dvp);
newentrysize = LFS_DIRSIZ(0, dirp, 0);
if (ulr->ulr_count == 0) {
/*
* If ulr_count is 0, then namei could find no
* space in the directory. Here, ulr_offset will
* be on a directory block boundary and we will write the
* new entry into a fresh block.
*/
if (ulr->ulr_offset & (dirblksiz - 1))
panic("ulfs_direnter: newblk");
if ((error = lfs_balloc(dvp, (off_t)ulr->ulr_offset, dirblksiz,
cr, B_CLRBUF | B_SYNC, &bp)) != 0) {
return (error);
}
dp->i_size = ulr->ulr_offset + dirblksiz;
DIP_ASSIGN(dp, size, dp->i_size);
dp->i_flag |= IN_CHANGE | IN_UPDATE;
uvm_vnp_setsize(dvp, dp->i_size);
dirp->d_reclen = ulfs_rw16(dirblksiz, needswap);
dirp->d_ino = ulfs_rw32(dirp->d_ino, needswap);
if (FSFMT(dvp)) {
#if (BYTE_ORDER == LITTLE_ENDIAN)
if (needswap == 0) {
#else
if (needswap != 0) {
#endif
u_char tmp = dirp->d_namlen;
dirp->d_namlen = dirp->d_type;
dirp->d_type = tmp;
}
}
lfs_blkoff = ulr->ulr_offset & (ump->um_mountp->mnt_stat.f_iosize - 1);
memcpy((char *)bp->b_data + lfs_blkoff, dirp, newentrysize);
#ifdef LFS_DIRHASH
if (dp->i_dirhash != NULL) {
ulfsdirhash_newblk(dp, ulr->ulr_offset);
ulfsdirhash_add(dp, dirp, ulr->ulr_offset);
ulfsdirhash_checkblock(dp, (char *)bp->b_data + lfs_blkoff,
ulr->ulr_offset);
}
#endif
error = VOP_BWRITE(bp->b_vp, bp);
vfs_timestamp(&ts);
ret = lfs_update(dvp, &ts, &ts, UPDATE_DIROP);
if (error == 0)
return (ret);
return (error);
}
/*
* If ulr_count is non-zero, then namei found space for the new
* entry in the range ulr_offset to ulr_offset + ulr_count
* in the directory. To use this space, we may have to compact
* the entries located there, by copying them together towards the
* beginning of the block, leaving the free space in one usable
* chunk at the end.
*/
/*
* Increase size of directory if entry eats into new space.
* This should never push the size past a new multiple of
* DIRBLKSIZ.
*
* N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
*/
if (ulr->ulr_offset + ulr->ulr_count > dp->i_size) {
#ifdef DIAGNOSTIC
printf("ulfs_direnter: reached 4.2-only block, "
"not supposed to happen\n");
#endif
dp->i_size = ulr->ulr_offset + ulr->ulr_count;
DIP_ASSIGN(dp, size, dp->i_size);
dp->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* Get the block containing the space for the new directory entry.
*/
error = ulfs_blkatoff(dvp, (off_t)ulr->ulr_offset, &dirbuf, &bp, true);
if (error) {
return (error);
}
/*
* Find space for the new entry. In the simple case, the entry at
* offset base will have the space. If it does not, then namei
* arranged that compacting the region ulr_offset to
* ulr_offset + ulr_count would yield the space.
*/
ep = (struct lfs_direct *)dirbuf;
dsize = (ep->d_ino != 0) ? LFS_DIRSIZ(FSFMT(dvp), ep, needswap) : 0;
spacefree = ulfs_rw16(ep->d_reclen, needswap) - dsize;
for (loc = ulfs_rw16(ep->d_reclen, needswap); loc < ulr->ulr_count; ) {
uint16_t reclen;
nep = (struct lfs_direct *)(dirbuf + loc);
/* Trim the existing slot (NB: dsize may be zero). */
ep->d_reclen = ulfs_rw16(dsize, needswap);
ep = (struct lfs_direct *)((char *)ep + dsize);
reclen = ulfs_rw16(nep->d_reclen, needswap);
loc += reclen;
if (nep->d_ino == 0) {
/*
* A mid-block unused entry. Such entries are
* never created by the kernel, but fsck_ffs
* can create them (and it doesn't fix them).
*
* Add up the free space, and initialise the
* relocated entry since we don't memcpy it.
*/
spacefree += reclen;
ep->d_ino = 0;
dsize = 0;
continue;
}
dsize = LFS_DIRSIZ(FSFMT(dvp), nep, needswap);
spacefree += reclen - dsize;
#ifdef LFS_DIRHASH
if (dp->i_dirhash != NULL)
ulfsdirhash_move(dp, nep,
ulr->ulr_offset + ((char *)nep - dirbuf),
ulr->ulr_offset + ((char *)ep - dirbuf));
#endif
memcpy((void *)ep, (void *)nep, dsize);
}
/*
* Here, `ep' points to a directory entry containing `dsize' in-use
* bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
* then the entry is completely unused (dsize == 0). The value
* of ep->d_reclen is always indeterminate.
*
* Update the pointer fields in the previous entry (if any),
* copy in the new entry, and write out the block.
*/
if (ep->d_ino == 0 ||
(ulfs_rw32(ep->d_ino, needswap) == ULFS_WINO &&
memcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
if (spacefree + dsize < newentrysize)
panic("ulfs_direnter: compact1");
dirp->d_reclen = spacefree + dsize;
} else {
if (spacefree < newentrysize)
panic("ulfs_direnter: compact2");
dirp->d_reclen = spacefree;
ep->d_reclen = ulfs_rw16(dsize, needswap);
ep = (struct lfs_direct *)((char *)ep + dsize);
}
dirp->d_reclen = ulfs_rw16(dirp->d_reclen, needswap);
dirp->d_ino = ulfs_rw32(dirp->d_ino, needswap);
if (FSFMT(dvp)) {
#if (BYTE_ORDER == LITTLE_ENDIAN)
if (needswap == 0) {
#else
if (needswap != 0) {
#endif
u_char tmp = dirp->d_namlen;
dirp->d_namlen = dirp->d_type;
dirp->d_type = tmp;
}
}
#ifdef LFS_DIRHASH
if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
dirp->d_reclen == spacefree))
ulfsdirhash_add(dp, dirp, ulr->ulr_offset + ((char *)ep - dirbuf));
#endif
memcpy((void *)ep, (void *)dirp, (u_int)newentrysize);
#ifdef LFS_DIRHASH
if (dp->i_dirhash != NULL)
ulfsdirhash_checkblock(dp, dirbuf -
(ulr->ulr_offset & (dirblksiz - 1)),
ulr->ulr_offset & ~(dirblksiz - 1));
#endif
error = VOP_BWRITE(bp->b_vp, bp);
dp->i_flag |= IN_CHANGE | IN_UPDATE;
/*
* If all went well, and the directory can be shortened, proceed
* with the truncation. Note that we have to unlock the inode for
* the entry that we just entered, as the truncation may need to
* lock other inodes which can lead to deadlock if we also hold a
* lock on the newly entered node.
*/
if (error == 0 && ulr->ulr_endoff && ulr->ulr_endoff < dp->i_size) {
#ifdef LFS_DIRHASH
if (dp->i_dirhash != NULL)
ulfsdirhash_dirtrunc(dp, ulr->ulr_endoff);
#endif
(void) lfs_truncate(dvp, (off_t)ulr->ulr_endoff, IO_SYNC, cr);
}
return (error);
}
/*
* Remove a directory entry after a call to namei, using the
* parameters that ulfs_lookup left in nameidata and in the
* ulfs_lookup_results.
*
* DVP is the directory to be updated. It must be locked.
* ULR is the ulfs_lookup_results structure from the final lookup step.
* IP, if not null, is the inode being unlinked.
* FLAGS may contain DOWHITEOUT.
* ISRMDIR is not used and (XXX) should be removed.
*
* If FLAGS contains DOWHITEOUT the entry is replaced with a whiteout
* instead of being cleared.
*
* ulr->ulr_offset contains the position of the directory entry
* to be removed.
*
* ulr->ulr_reclen contains the size of the directory entry to be
* removed.
*
* ulr->ulr_count contains the size of the *previous* directory
* entry. This allows finding it, for free space management. If
* ulr_count is 0, the target entry is at the beginning of the
* directory. (Does this ever happen? The first entry should be ".",
* which should only be removed at rmdir time. Does rmdir come here
* to clear out the "." and ".." entries? Perhaps, but I doubt it.)
*
* The space is marked free by adding it to the record length (not
* name length) of the preceding entry. If the first entry becomes
* free, it is marked free by setting the inode number to 0.
*
* The link count of IP is decremented. Note that this is not the
* inverse behavior of ulfs_direnter, which does not adjust link
* counts. Sigh.
*/
int
ulfs_dirremove(struct vnode *dvp, const struct ulfs_lookup_results *ulr,
struct inode *ip, int flags, int isrmdir)
{
struct inode *dp = VTOI(dvp);
struct lfs_direct *ep;
struct buf *bp;
int error;
const int needswap = ULFS_MPNEEDSWAP(dp->i_lfs);
if (flags & DOWHITEOUT) {
/*
* Whiteout entry: set d_ino to ULFS_WINO.
*/
error = ulfs_blkatoff(dvp, (off_t)ulr->ulr_offset, (void *)&ep,
&bp, true);
if (error)
return (error);
ep->d_ino = ulfs_rw32(ULFS_WINO, needswap);
ep->d_type = LFS_DT_WHT;
goto out;
}
if ((error = ulfs_blkatoff(dvp,
(off_t)(ulr->ulr_offset - ulr->ulr_count), (void *)&ep, &bp, true)) != 0)
return (error);
#ifdef LFS_DIRHASH
/*
* Remove the dirhash entry. This is complicated by the fact
* that `ep' is the previous entry when ulr_count != 0.
*/
if (dp->i_dirhash != NULL)
ulfsdirhash_remove(dp, (ulr->ulr_count == 0) ? ep :
(struct lfs_direct *)((char *)ep +
ulfs_rw16(ep->d_reclen, needswap)), ulr->ulr_offset);
#endif
if (ulr->ulr_count == 0) {
/*
* First entry in block: set d_ino to zero.
*/
ep->d_ino = 0;
} else {
/*
* Collapse new free space into previous entry.
*/
ep->d_reclen =
ulfs_rw16(ulfs_rw16(ep->d_reclen, needswap) + ulr->ulr_reclen,
needswap);
}
#ifdef LFS_DIRHASH
if (dp->i_dirhash != NULL) {
int dirblksiz = ip->i_lfs->um_dirblksiz;
ulfsdirhash_checkblock(dp, (char *)ep -
((ulr->ulr_offset - ulr->ulr_count) & (dirblksiz - 1)),
ulr->ulr_offset & ~(dirblksiz - 1));
}
#endif
out:
if (ip) {
ip->i_nlink--;
DIP_ASSIGN(ip, nlink, ip->i_nlink);
ip->i_flag |= IN_CHANGE;
}
/*
* XXX did it ever occur to anyone that it might be a good
* idea to restore ip->i_nlink if this fails? Or something?
* Currently on error return from this function the state of
* ip->i_nlink depends on what happened, and callers
* definitely do not take this into account.
*/
error = VOP_BWRITE(bp->b_vp, bp);
dp->i_flag |= IN_CHANGE | IN_UPDATE;
/*
* If the last named reference to a snapshot goes away,
* drop its snapshot reference so that it will be reclaimed
* when last open reference goes away.
*/
if (ip != 0 && (ip->i_flags & SF_SNAPSHOT) != 0 &&
ip->i_nlink == 0)
ulfs_snapgone(ip);
return (error);
}
/*
* Rewrite an existing directory entry to point at the inode supplied.
*
* DP is the directory to update.
* OFFSET is the position of the entry in question. It may come
* from ulr_offset of a ulfs_lookup_results.
* OIP is the old inode the directory previously pointed to.
* NEWINUM is the number of the new inode.
* NEWTYPE is the new value for the type field of the directory entry.
* (This is ignored if the fs doesn't support that.)
* ISRMDIR is not used and (XXX) should be removed.
* IFLAGS are added to DP's inode flags.
*
* The link count of OIP is decremented. Note that the link count of
* the new inode is *not* incremented. Yay for symmetry.
*/
int
ulfs_dirrewrite(struct inode *dp, off_t offset,
struct inode *oip, ino_t newinum, int newtype,
int isrmdir, int iflags)
{
struct buf *bp;
struct lfs_direct *ep;
struct vnode *vdp = ITOV(dp);
int error;
error = ulfs_blkatoff(vdp, offset, (void *)&ep, &bp, true);
if (error)
return (error);
ep->d_ino = ulfs_rw32(newinum, ULFS_IPNEEDSWAP(dp));
if (!FSFMT(vdp))
ep->d_type = newtype;
oip->i_nlink--;
DIP_ASSIGN(oip, nlink, oip->i_nlink);
oip->i_flag |= IN_CHANGE;
error = VOP_BWRITE(bp->b_vp, bp);
dp->i_flag |= iflags;
/*
* If the last named reference to a snapshot goes away,
* drop its snapshot reference so that it will be reclaimed
* when last open reference goes away.
*/
if ((oip->i_flags & SF_SNAPSHOT) != 0 && oip->i_nlink == 0)
ulfs_snapgone(oip);
return (error);
}
/*
* Check if a directory is empty or not.
* Inode supplied must be locked.
*
* Using a struct lfs_dirtemplate here is not precisely
* what we want, but better than using a struct lfs_direct.
*
* NB: does not handle corrupted directories.
*/
int
ulfs_dirempty(struct inode *ip, ino_t parentino, kauth_cred_t cred)
{
doff_t off;
struct lfs_dirtemplate dbuf;
struct lfs_direct *dp = (struct lfs_direct *)&dbuf;
int error, namlen;
size_t count;
const int needswap = ULFS_IPNEEDSWAP(ip);
#define MINDIRSIZ (sizeof (struct lfs_dirtemplate) / 2)
for (off = 0; off < ip->i_size;
off += ulfs_rw16(dp->d_reclen, needswap)) {
error = vn_rdwr(UIO_READ, ITOV(ip), (void *)dp, MINDIRSIZ, off,
UIO_SYSSPACE, IO_NODELOCKED, cred, &count, NULL);
/*
* Since we read MINDIRSIZ, residual must
* be 0 unless we're at end of file.
*/
if (error || count != 0)
return (0);
/* avoid infinite loops */
if (dp->d_reclen == 0)
return (0);
/* skip empty entries */
if (dp->d_ino == 0 || ulfs_rw32(dp->d_ino, needswap) == ULFS_WINO)
continue;
/* accept only "." and ".." */
#if (BYTE_ORDER == LITTLE_ENDIAN)
if (FSFMT(ITOV(ip)) && needswap == 0)
namlen = dp->d_type;
else
namlen = dp->d_namlen;
#else
if (FSFMT(ITOV(ip)) && needswap != 0)
namlen = dp->d_type;
else
namlen = dp->d_namlen;
#endif
if (namlen > 2)
return (0);
if (dp->d_name[0] != '.')
return (0);
/*
* At this point namlen must be 1 or 2.
* 1 implies ".", 2 implies ".." if second
* char is also "."
*/
if (namlen == 1 &&
ulfs_rw32(dp->d_ino, needswap) == ip->i_number)
continue;
if (dp->d_name[1] == '.' &&
ulfs_rw32(dp->d_ino, needswap) == parentino)
continue;
return (0);
}
return (1);
}
#define ULFS_DIRRABLKS 0
int ulfs_dirrablks = ULFS_DIRRABLKS;
/*
* ulfs_blkatoff: Return buffer with the contents of block "offset" from
* the beginning of directory "vp". If "res" is non-NULL, fill it in with
* a pointer to the remaining space in the directory. If the caller intends
* to modify the buffer returned, "modify" must be true.
*/
int
ulfs_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp,
bool modify)
{
struct inode *ip __diagused;
struct buf *bp;
daddr_t lbn;
const int dirrablks = ulfs_dirrablks;
daddr_t *blks;
int *blksizes;
int run, error;
struct mount *mp = vp->v_mount;
const int bshift = mp->mnt_fs_bshift;
const int bsize = 1 << bshift;
off_t eof;
blks = kmem_alloc((1 + dirrablks) * sizeof(daddr_t), KM_SLEEP);
blksizes = kmem_alloc((1 + dirrablks) * sizeof(int), KM_SLEEP);
ip = VTOI(vp);
KASSERT(vp->v_size == ip->i_size);
GOP_SIZE(vp, vp->v_size, &eof, 0);
lbn = offset >> bshift;
for (run = 0; run <= dirrablks;) {
const off_t curoff = lbn << bshift;
const int size = MIN(eof - curoff, bsize);
if (size == 0) {
break;
}
KASSERT(curoff < eof);
blks[run] = lbn;
blksizes[run] = size;
lbn++;
run++;
if (size != bsize) {
break;
}
}
KASSERT(run >= 1);
error = breadn(vp, blks[0], blksizes[0], &blks[1], &blksizes[1],
run - 1, NOCRED, (modify ? B_MODIFY : 0), &bp);
if (error != 0) {
*bpp = NULL;
goto out;
}
if (res) {
*res = (char *)bp->b_data + (offset & (bsize - 1));
}
*bpp = bp;
out:
kmem_free(blks, (1 + dirrablks) * sizeof(daddr_t));
kmem_free(blksizes, (1 + dirrablks) * sizeof(int));
return error;
}