aboutsummaryrefslogtreecommitdiff
path: root/sys/pcfs/pcfs_denode.c
diff options
context:
space:
mode:
Diffstat (limited to 'sys/pcfs/pcfs_denode.c')
-rw-r--r--sys/pcfs/pcfs_denode.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/sys/pcfs/pcfs_denode.c b/sys/pcfs/pcfs_denode.c
new file mode 100644
index 000000000000..888f0185bd3a
--- /dev/null
+++ b/sys/pcfs/pcfs_denode.c
@@ -0,0 +1,621 @@
+/*
+ * Written by Paul Popelka (paulp@uts.amdahl.com)
+ *
+ * You can do anything you want with this software,
+ * just don't say you wrote it,
+ * and don't reoove this notice.
+ *
+ * This software is provided "as is".
+ *
+ * The authop supplies this software to be publicly
+ * redistributed on the understanding that the author
+ * is not responsible for the correct functioning of
+ * this software in any circumstances and is not liable
+ * for any damages caused by this software.
+ *
+ * October 1992
+ *
+ * $Id: pcfs_denode.c,v 1.2 1993/10/16 19:29:32 rgrimes Exp $
+ */
+
+#include "param.h"
+#include "systm.h"
+#include "mount.h"
+#include "proc.h"
+#include "buf.h"
+#include "vnode.h"
+#include "kernel.h" /* defines "time" */
+
+#include "bpb.h"
+#include "pcfsmount.h"
+#include "direntry.h"
+#include "denode.h"
+#include "fat.h"
+
+#define DEHSZ 512
+#if ((DEHSZ & (DEHSZ-1)) == 0)
+#define DEHASH(dev, deno) (((dev)+(deno)+((deno)>>16))&(DEHSZ-1))
+#else
+#define DEHASH(dev, deno) (((dev)+(deno)+((deno)>>16))%DEHSZ)
+#endif /* ((DEHSZ & (DEHSZ-1)) == 0) */
+
+union dehead {
+ union dehead *deh_head[2];
+ struct denode *deh_chain[2];
+} dehead[DEHSZ];
+
+pcfs_init()
+{
+ int i;
+ union dehead *deh;
+
+ if (VN_MAXPRIVATE < sizeof(struct denode))
+ panic("pcfs_init: vnode too small");
+
+ for (i = DEHSZ, deh = dehead; --i >= 0; deh++) {
+ deh->deh_head[0] = deh;
+ deh->deh_head[1] = deh;
+ }
+}
+
+/*
+ * If deget() succeeds it returns with the gotten denode
+ * locked().
+ * pmp - address of pcfsmount structure of the filesystem
+ * containing the denode of interest. The pm_dev field
+ * and the address of the pcfsmount structure are used.
+ * dirclust - which cluster bp contains, if dirclust is 0
+ * (root directory) diroffset is relative to the beginning
+ * of the root directory, otherwise it is cluster relative.
+ * diroffset - offset past begin of cluster of denode we
+ * want
+ * direntptr - address of the direntry structure of interest.
+ * direntptr is NULL, the block is read if necessary.
+ * depp - returns the address of the gotten denode.
+ */
+int
+deget (pmp, dirclust, diroffset, direntptr, depp)
+ struct pcfsmount *pmp; /* so we know the maj/min number */
+ u_long dirclust; /* cluster this dir entry came from */
+ u_long diroffset; /* index of entry within the cluster */
+ struct direntry *direntptr;
+ struct denode **depp; /* returns the addr of the gotten denode*/
+{
+ int error;
+ dev_t dev = pmp->pm_dev;
+ union dehead *deh;
+ struct mount *mntp = pmp->pm_mountp;
+ extern struct vnodeops pcfs_vnodeops;
+ struct denode *ldep;
+ struct vnode *nvp;
+ struct buf *bp;
+#if defined(PCFSDEBUG)
+printf("deget(pmp %08x, dirclust %d, diroffset %x, direntptr %x, depp %08x)\n",
+ pmp, dirclust, diroffset, direntptr, depp);
+#endif /* defined(PCFSDEBUG) */
+
+ /* If dir entry is given and refers to a directory, convert to
+ * canonical form
+ */
+ if (direntptr && (direntptr->deAttributes & ATTR_DIRECTORY)) {
+ dirclust = direntptr->deStartCluster;
+ if (dirclust == PCFSROOT)
+ diroffset = PCFSROOT_OFS;
+ else
+ diroffset = 0;
+ }
+
+/*
+ * See if the denode is in the denode cache. Use the location of
+ * the directory entry to compute the hash value.
+ * For subdir use address of "." entry.
+ * for root dir use cluster PCFSROOT, offset PCFSROOT_OFS
+ *
+ * NOTE: The check for de_refcnt > 0 below insures the denode
+ * being examined does not represent an unlinked but
+ * still open file. These files are not to be accessible
+ * even when the directory entry that represented the
+ * file happens to be reused while the deleted file is still
+ * open.
+ */
+ deh = &dehead[DEHASH(dev, dirclust + diroffset)];
+loop:
+ for (ldep = deh->deh_chain[0]; ldep != (struct denode *)deh;
+ ldep = ldep->de_forw) {
+ if (dev != ldep->de_dev || ldep->de_refcnt == 0)
+ continue;
+ if (dirclust != ldep->de_dirclust
+ || diroffset != ldep->de_diroffset)
+ continue;
+ if (ldep->de_flag & DELOCKED) {
+ /* should we brelse() the passed buf hdr to
+ * avoid some potential deadlock? */
+ ldep->de_flag |= DEWANT;
+ sleep((caddr_t)ldep, PINOD);
+ goto loop;
+ }
+ if (vget(DETOV(ldep)))
+ goto loop;
+ *depp = ldep;
+ return 0;
+ }
+
+
+/*
+ * Directory entry was not in cache, have to create
+ * a vnode and copy it from the passed disk buffer.
+ */
+ /* getnewvnode() does a VREF() on the vnode */
+ if (error = getnewvnode(VT_PCFS, mntp, &pcfs_vnodeops, &nvp)) {
+ *depp = 0;
+ return error;
+ }
+ ldep = VTODE(nvp);
+ ldep->de_vnode = nvp;
+ ldep->de_flag = 0;
+ ldep->de_devvp = 0;
+ ldep->de_lockf = 0;
+ ldep->de_dev = dev;
+ fc_purge(ldep, 0); /* init the fat cache for this denode */
+
+/*
+ * Insert the denode into the hash queue and lock the
+ * denode so it can't be accessed until we've read it
+ * in and have done what we need to it.
+ */
+ insque(ldep, deh);
+ DELOCK(ldep);
+
+ /*
+ * Copy the directory entry into the denode area of the
+ * vnode.
+ */
+ if (dirclust == PCFSROOT && diroffset == PCFSROOT_OFS) {
+ /* Directory entry for the root directory.
+ * There isn't one, so we manufacture one.
+ * We should probably rummage through the root directory and
+ * find a label entry (if it exists), and then use the time
+ * and date from that entry as the time and date for the
+ * root denode.
+ */
+ ldep->de_Attributes = ATTR_DIRECTORY;
+ ldep->de_StartCluster = PCFSROOT;
+ ldep->de_FileSize = pmp->pm_rootdirsize * 512; /* Jim Jegers*/
+ /* fill in time and date so that dos2unixtime() doesn't
+ * spit up when called from pcfs_getattr() with root denode */
+ ldep->de_Time = 0x0000; /* 00:00:00 */
+ ldep->de_Date = (0 << 9) | (1 << 5) | (1 << 0);
+ /* Jan 1, 1980 */
+ /* leave the other fields as garbage */
+ }
+ else {
+ bp = NULL;
+ if (!direntptr) {
+ error = readep(pmp, dirclust, diroffset, &bp,
+ &direntptr);
+ if (error)
+ return error;
+ }
+ ldep->de_de = *direntptr;
+ if (bp)
+ brelse (bp);
+ }
+
+/*
+ * Fill in a few fields of the vnode and finish filling
+ * in the denode. Then return the address of the found
+ * denode.
+ */
+ ldep->de_pmp = pmp;
+ ldep->de_devvp = pmp->pm_devvp;
+ ldep->de_refcnt = 1;
+ ldep->de_dirclust = dirclust;
+ ldep->de_diroffset = diroffset;
+ if (ldep->de_Attributes & ATTR_DIRECTORY) {
+ /*
+ * Since DOS directory entries that describe directories
+ * have 0 in the filesize field, we take this opportunity
+ * to find out the length of the directory and plug it
+ * into the denode structure.
+ */
+ u_long size;
+
+ nvp->v_type = VDIR;
+ if (ldep->de_StartCluster == PCFSROOT)
+ nvp->v_flag |= VROOT;
+ else {
+ error = pcbmap(ldep, 0xffff, 0, &size);
+ if (error == E2BIG) {
+ ldep->de_FileSize = size << pmp->pm_cnshift;
+ error = 0;
+ }
+ else
+ printf("deget(): pcbmap returned %d\n", error);
+ }
+ }
+ else
+ nvp->v_type = VREG;
+ VREF(ldep->de_devvp);
+ *depp = ldep;
+ return 0;
+}
+
+void
+deput(dep)
+ struct denode *dep;
+{
+ if ((dep->de_flag & DELOCKED) == 0)
+ panic("deput: denode not locked");
+ DEUNLOCK(dep);
+ vrele(DETOV(dep));
+}
+
+int
+deupdat(dep, tp, waitfor)
+ struct denode *dep;
+ struct timeval *tp;
+ int waitfor;
+{
+ int error;
+ daddr_t bn;
+ int diro;
+ struct buf *bp;
+ struct direntry *dirp;
+ struct pcfsmount *pmp = dep->de_pmp;
+ struct vnode *vp = DETOV(dep);
+#if defined(PCFSDEBUG)
+printf("deupdat(): dep %08x\n", dep);
+#endif /* defined(PCFSDEBUG) */
+
+/*
+ * If the update bit is off, or this denode is from
+ * a readonly filesystem, or this denode is for a
+ * directory, or the denode represents an open but
+ * unlinked file then don't do anything. DOS directory
+ * entries that describe a directory do not ever
+ * get updated. This is the way dos treats them.
+ */
+ if ((dep->de_flag & DEUPD) == 0 ||
+ vp->v_mount->mnt_flag & MNT_RDONLY ||
+ dep->de_Attributes & ATTR_DIRECTORY ||
+ dep->de_refcnt <= 0)
+ return 0;
+
+/*
+ * Read in the cluster containing the directory entry
+ * we want to update.
+ */
+ if (error = readde(dep, &bp, &dirp))
+ return error;
+
+/*
+ * Put the passed in time into the directory entry.
+ */
+ unix2dostime(&time, (union dosdate *)&dep->de_Date,
+ (union dostime *)&dep->de_Time);
+ dep->de_flag &= ~DEUPD;
+
+/*
+ * Copy the directory entry out of the denode into
+ * the cluster it came from.
+ */
+ *dirp = dep->de_de; /* structure copy */
+
+/*
+ * Write the cluster back to disk. If they asked
+ * for us to wait for the write to complete, then
+ * use bwrite() otherwise use bdwrite().
+ */
+ error = 0; /* note that error is 0 from above, but ... */
+ if (waitfor)
+ error = bwrite(bp);
+ else
+ bdwrite(bp);
+ return error;
+}
+
+/*
+ * Truncate the file described by dep to the length
+ * specified by length.
+ */
+int
+detrunc(dep, length, flags)
+ struct denode *dep;
+ u_long length;
+ int flags;
+{
+ int error;
+ int allerror;
+ u_long eofentry;
+ u_long chaintofree;
+ daddr_t bn;
+ int boff;
+ int isadir = dep->de_Attributes & ATTR_DIRECTORY;
+ struct buf *bp;
+ struct pcfsmount *pmp = dep->de_pmp;
+#if defined(PCFSDEBUG)
+printf("detrunc(): file %s, length %d, flags %d\n", dep->de_Name, length, flags);
+#endif /* defined(PCFSDEBUG) */
+
+/*
+ * Disallow attempts to truncate the root directory
+ * since it is of fixed size. That's just the way
+ * dos filesystems are. We use the VROOT bit in the
+ * vnode because checking for the directory bit and
+ * a startcluster of 0 in the denode is not adequate
+ * to recognize the root directory at this point in
+ * a file or directory's life.
+ */
+ if (DETOV(dep)->v_flag & VROOT) {
+ printf("detrunc(): can't truncate root directory, clust %d, offset %d\n",
+ dep->de_dirclust, dep->de_diroffset);
+ return EINVAL;
+ }
+
+ vnode_pager_setsize(DETOV(dep), length);
+
+ if (dep->de_FileSize <= length) {
+ dep->de_flag |= DEUPD;
+ error = deupdat(dep, &time, 1);
+#if defined(PCFSDEBUG)
+printf("detrunc(): file is shorter return point, errno %d\n", error);
+#endif /* defined(PCFSDEBUG) */
+ return error;
+ }
+
+/*
+ * If the desired length is 0 then remember the starting
+ * cluster of the file and set the StartCluster field in
+ * the directory entry to 0. If the desired length is
+ * not zero, then get the number of the last cluster in
+ * the shortened file. Then get the number of the first
+ * cluster in the part of the file that is to be freed.
+ * Then set the next cluster pointer in the last cluster
+ * of the file to CLUST_EOFE.
+ */
+ if (length == 0) {
+ chaintofree = dep->de_StartCluster;
+ dep->de_StartCluster = 0;
+ eofentry = ~0;
+ } else {
+ error = pcbmap(dep, (length-1) >> pmp->pm_cnshift,
+ 0, &eofentry);
+ if (error) {
+#if defined(PCFSDEBUG)
+printf("detrunc(): pcbmap fails %d\n", error);
+#endif /* defined(PCFSDEBUG) */
+ return error;
+ }
+ }
+
+ fc_purge(dep, (length + pmp->pm_crbomask) >> pmp->pm_cnshift);
+
+/*
+ * If the new length is not a multiple of the cluster size
+ * then we must zero the tail end of the new last cluster in case
+ * it becomes part of the file again because of a seek.
+ */
+ if ((boff = length & pmp->pm_crbomask) != 0) {
+ /* should read from file vnode or
+ * filesystem vnode depending on if file or dir */
+ if (isadir) {
+ bn = cntobn(pmp, eofentry);
+ error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
+ NOCRED, &bp);
+ } else {
+ bn = (length-1) >> pmp->pm_cnshift;
+ error = bread(DETOV(dep), bn, pmp->pm_bpcluster,
+ NOCRED, &bp);
+ }
+ if (error) {
+#if defined(PCFSDEBUG)
+printf("detrunc(): bread fails %d\n", error);
+#endif /* defined(PCFSDEBUG) */
+ return error;
+ }
+ vnode_pager_uncache(DETOV(dep)); /* what's this for? */
+ /* is this the right
+ * place for it? */
+ bzero(bp->b_un.b_addr + boff, pmp->pm_bpcluster - boff);
+ if (flags & IO_SYNC)
+ bwrite(bp);
+ else
+ bdwrite(bp);
+ }
+
+/*
+ * Write out the updated directory entry. Even
+ * if the update fails we free the trailing clusters.
+ */
+ dep->de_FileSize = length;
+ dep->de_flag |= DEUPD;
+ vinvalbuf(DETOV(dep), length > 0);
+ allerror = deupdat(dep, &time, MNT_WAIT);
+#if defined(PCFSDEBUG)
+printf("detrunc(): allerror %d, eofentry %d\n",
+ allerror, eofentry);
+#endif /* defined(PCFSDEBUG) */
+
+/*
+ * If we need to break the cluster chain for the file
+ * then do it now.
+ */
+ if (eofentry != ~0) {
+ error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
+ &chaintofree, CLUST_EOFE);
+ if (error) {
+#if defined(PCFSDEBUG)
+printf("detrunc(): fatentry errors %d\n", error);
+#endif /* defined(PCFSDEBUG) */
+ return error;
+ }
+ fc_setcache(dep, FC_LASTFC, (length - 1) >> pmp->pm_cnshift,
+ eofentry);
+ }
+
+/*
+ * Now free the clusters removed from the file because
+ * of the truncation.
+ */
+ if (chaintofree != 0 && !PCFSEOF(chaintofree))
+ freeclusterchain(pmp, chaintofree);
+
+ return allerror;
+}
+
+/*
+ * Move a denode to its correct hash queue after
+ * the file it represents has been moved to a new
+ * directory.
+ */
+reinsert(dep)
+ struct denode *dep;
+{
+ struct pcfsmount *pmp = dep->de_pmp;
+ union dehead *deh;
+
+/*
+ * Fix up the denode cache. If the denode is
+ * for a directory, there is nothing to do since the
+ * hash is based on the starting cluster of the directory
+ * file and that hasn't changed. If for a file the hash
+ * is based on the location
+ * of the directory entry, so we must remove it from the
+ * cache and re-enter it with the hash based on the new
+ * location of the directory entry.
+ */
+ if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
+ remque(dep);
+ deh = &dehead[DEHASH(pmp->pm_dev,
+ dep->de_dirclust + dep->de_diroffset)];
+ insque(dep, deh);
+ }
+}
+
+int pcfs_prtactive; /* print reclaims of active vnodes */
+
+int
+pcfs_reclaim(vp)
+ struct vnode *vp;
+{
+ struct denode *dep = VTODE(vp);
+ int i;
+#if defined(PCFSDEBUG)
+printf("pcfs_reclaim(): dep %08x, file %s, refcnt %d\n",
+ dep, dep->de_Name, dep->de_refcnt);
+#endif /* defined(PCFSDEBUG) */
+
+ if (pcfs_prtactive && vp->v_usecount != 0)
+ vprint("pcfs_reclaim(): pushing active", vp);
+
+/*
+ * Remove the denode from the denode hash chain we
+ * are in.
+ */
+ remque(dep);
+ dep->de_forw = dep;
+ dep->de_back = dep;
+
+ cache_purge(vp);
+/*
+ * Indicate that one less file on the filesystem is open.
+ */
+ if (dep->de_devvp) {
+ vrele(dep->de_devvp);
+ dep->de_devvp = 0;
+ }
+
+ dep->de_flag = 0;
+ return 0;
+}
+
+int
+pcfs_inactive(vp, p)
+ struct vnode *vp;
+ struct proc *p;
+{
+ struct denode *dep = VTODE(vp);
+ int error = 0;
+#if defined(PCFSDEBUG)
+printf("pcfs_inactive(): dep %08x, de_Name[0] %x\n", dep, dep->de_Name[0]);
+#endif /* defined(PCFSDEBUG) */
+
+ if (pcfs_prtactive && vp->v_usecount != 0)
+ vprint("pcfs_inactive(): pushing active", vp);
+
+/*
+ * Get rid of denodes related to stale file handles.
+ * Hmmm, what does this really do?
+ */
+ if (dep->de_Name[0] == SLOT_DELETED) {
+ if ((vp->v_flag & VXLOCK) == 0)
+ vgone(vp);
+ return 0;
+ }
+
+/*
+ * If the file has been deleted and it is on a read/write
+ * filesystem, then truncate the file, and mark the directory
+ * slot as empty. (This may not be necessary for the dos
+ * filesystem.
+ */
+#if defined(PCFSDEBUG)
+printf("pcfs_inactive(): dep %08x, refcnt %d, mntflag %x, MNT_RDONLY %x\n",
+ dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
+#endif /* defined(PCFSDEBUG) */
+ DELOCK(dep);
+ if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
+ error = detrunc(dep, (u_long)0, 0);
+ dep->de_flag |= DEUPD;
+ dep->de_Name[0] = SLOT_DELETED;
+ }
+ DEUPDAT(dep, &time, 0);
+ DEUNLOCK(dep);
+ dep->de_flag = 0;
+
+/*
+ * If we are done with the denode, then reclaim
+ * it so that it can be reused now.
+ */
+#if defined(PCFSDEBUG)
+printf("pcfs_inactive(): v_usecount %d, de_Name[0] %x\n", vp->v_usecount,
+ dep->de_Name[0]);
+#endif /* defined(PCFSDEBUG) */
+ if (vp->v_usecount == 0 && dep->de_Name[0] == SLOT_DELETED)
+ vgone(vp);
+ return error;
+}
+
+int
+delock(dep)
+ struct denode *dep;
+{
+ while (dep->de_flag & DELOCKED) {
+ dep->de_flag |= DEWANT;
+ if (dep->de_spare0 == curproc->p_pid)
+ panic("delock: locking against myself");
+ dep->de_spare1 = curproc->p_pid;
+ (void) sleep((caddr_t)dep, PINOD);
+ }
+ dep->de_spare1 = 0;
+ dep->de_spare0 = curproc->p_pid;
+ dep->de_flag |= DELOCKED;
+
+ return 0;
+}
+
+int
+deunlock(dep)
+ struct denode *dep;
+{
+ if ((dep->de_flag & DELOCKED) == 0)
+ vprint("deunlock: found unlocked denode", DETOV(dep));
+ dep->de_spare0 = 0;
+ dep->de_flag &= ~DELOCKED;
+ if (dep->de_flag & DEWANT) {
+ dep->de_flag &= ~DEWANT;
+ wakeup((caddr_t)dep);
+ }
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-28 09:25:54 +0000