svn commit: r209716 - head/sbin/fsck_ffs
Jeff Roberson
jeff at FreeBSD.org
Tue Jul 6 07:07:29 UTC 2010
Author: jeff
Date: Tue Jul 6 07:07:29 2010
New Revision: 209716
URL: http://svn.freebsd.org/changeset/base/209716
Log:
- Permit zero length directories as a handled inconsistency. This allows
directory truncation to proceed before the link has been cleared. This
is accomplished by detecting a directory with no . or .. links and
clearing the named directory entry in the parent.
- Add a new function ino_remref() which handles the details of removing
a reference to an inode as a result of a lost directory. There were
some minor errors in various subcases of this routine.
Modified:
head/sbin/fsck_ffs/suj.c
Modified: head/sbin/fsck_ffs/suj.c
==============================================================================
--- head/sbin/fsck_ffs/suj.c Tue Jul 6 03:48:46 2010 (r209715)
+++ head/sbin/fsck_ffs/suj.c Tue Jul 6 07:07:29 2010 (r209716)
@@ -808,6 +808,44 @@ blk_isat(ino_t ino, ufs_lbn_t lbn, ufs2_
}
/*
+ * Clear the directory entry at diroff that should point to child. Minimal
+ * checking is done and it is assumed that this path was verified with isat.
+ */
+static void
+ino_clrat(ino_t parent, off_t diroff, ino_t child)
+{
+ union dinode *dip;
+ struct direct *dp;
+ ufs2_daddr_t blk;
+ uint8_t *block;
+ ufs_lbn_t lbn;
+ int blksize;
+ int frags;
+ int doff;
+
+ if (debug)
+ printf("Clearing inode %d from parent %d at offset %jd\n",
+ child, parent, diroff);
+
+ lbn = lblkno(fs, diroff);
+ doff = blkoff(fs, diroff);
+ dip = ino_read(parent);
+ blk = ino_blkatoff(dip, parent, lbn, &frags);
+ blksize = sblksize(fs, DIP(dip, di_size), lbn);
+ block = dblk_read(blk, blksize);
+ dp = (struct direct *)&block[doff];
+ if (dp->d_ino != child)
+ errx(1, "Inode %d does not exist in %d at %jd",
+ child, parent, diroff);
+ dp->d_ino = 0;
+ dblk_dirty(blk);
+ /*
+ * The actual .. reference count will already have been removed
+ * from the parent by the .. remref record.
+ */
+}
+
+/*
* Determines whether a pointer to an inode exists within a directory
* at a specified offset. Returns the mode of the found entry.
*/
@@ -1134,6 +1172,57 @@ ino_setskip(struct suj_ino *sino, ino_t
sino->si_skipparent = 1;
}
+static void
+ino_remref(ino_t parent, ino_t child, uint64_t diroff, int isdotdot)
+{
+ struct suj_ino *sino;
+ struct suj_rec *srec;
+ struct jrefrec *rrec;
+
+ /*
+ * Lookup this inode to see if we have a record for it.
+ */
+ sino = ino_lookup(child, 0);
+ /*
+ * Tell any child directories we've already removed their
+ * parent link cnt. Don't try to adjust our link down again.
+ */
+ if (sino != NULL && isdotdot == 0)
+ ino_setskip(sino, parent);
+ /*
+ * No valid record for this inode. Just drop the on-disk
+ * link by one.
+ */
+ if (sino == NULL || sino->si_hasrecs == 0) {
+ ino_decr(child);
+ return;
+ }
+ /*
+ * Use ino_adjust() if ino_check() has already processed this
+ * child. If we lose the last non-dot reference to a
+ * directory it will be discarded.
+ */
+ if (sino->si_linkadj) {
+ sino->si_nlink--;
+ if (isdotdot)
+ sino->si_dotlinks--;
+ ino_adjust(sino);
+ return;
+ }
+ /*
+ * If we haven't yet processed this inode we need to make
+ * sure we will successfully discover the lost path. If not
+ * use nlinkadj to remember.
+ */
+ TAILQ_FOREACH(srec, &sino->si_recs, sr_next) {
+ rrec = (struct jrefrec *)srec->sr_rec;
+ if (rrec->jr_parent == parent &&
+ rrec->jr_diroff == diroff)
+ return;
+ }
+ sino->si_nlinkadj++;
+}
+
/*
* Free the children of a directory when the directory is discarded.
*/
@@ -1141,13 +1230,11 @@ static void
ino_free_children(ino_t ino, ufs_lbn_t lbn, ufs2_daddr_t blk, int frags)
{
struct suj_ino *sino;
- struct suj_rec *srec;
- struct jrefrec *rrec;
struct direct *dp;
off_t diroff;
uint8_t *block;
int skipparent;
- int isparent;
+ int isdotdot;
int dpoff;
int size;
@@ -1165,53 +1252,15 @@ ino_free_children(ino_t ino, ufs_lbn_t l
continue;
if (dp->d_namlen == 1 && dp->d_name[0] == '.')
continue;
- isparent = dp->d_namlen == 2 && dp->d_name[0] == '.' &&
+ isdotdot = dp->d_namlen == 2 && dp->d_name[0] == '.' &&
dp->d_name[1] == '.';
- if (isparent && skipparent == 1)
+ if (isdotdot && skipparent == 1)
continue;
if (debug)
printf("Directory %d removing ino %d name %s\n",
ino, dp->d_ino, dp->d_name);
- /*
- * Lookup this inode to see if we have a record for it.
- * If not, we've already adjusted it assuming this path
- * was valid and we have to adjust once more.
- */
- sino = ino_lookup(dp->d_ino, 0);
- if (sino == NULL || sino->si_hasrecs == 0) {
- ino_decr(ino);
- continue;
- }
- /*
- * Use ino_adjust() so if we lose the last non-dot reference
- * to a directory it can be discarded.
- */
- if (sino->si_linkadj) {
- sino->si_nlink--;
- if (isparent)
- sino->si_dotlinks--;
- ino_adjust(sino);
- }
- /*
- * Tell any child directories we've already removed their
- * parent. Don't try to adjust our link down again.
- */
- if (isparent == 0)
- ino_setskip(sino, ino);
- /*
- * If we haven't yet processed this inode we need to make
- * sure we will successfully discover the lost path. If not
- * use nlinkadj to remember.
- */
diroff = lblktosize(fs, lbn) + dpoff;
- TAILQ_FOREACH(srec, &sino->si_recs, sr_next) {
- rrec = (struct jrefrec *)srec->sr_rec;
- if (rrec->jr_parent == ino &&
- rrec->jr_diroff == diroff)
- break;
- }
- if (srec == NULL)
- sino->si_nlinkadj++;
+ ino_remref(ino, dp->d_ino, diroff, isdotdot);
}
}
@@ -1293,18 +1342,38 @@ ino_adjust(struct suj_ino *sino)
struct suj_ino *stmp;
union dinode *ip;
nlink_t nlink;
+ int recmode;
int reqlink;
+ int isdot;
int mode;
ino_t ino;
nlink = sino->si_nlink;
ino = sino->si_ino;
+ mode = sino->si_mode & IFMT;
+ /*
+ * If it's a directory with no dot links, it was truncated before
+ * the name was cleared. We need to clear the dirent that
+ * points at it.
+ */
+ if (mode == IFDIR && nlink == 1 && sino->si_dotlinks == 0) {
+ sino->si_nlink = nlink = 0;
+ TAILQ_FOREACH(srec, &sino->si_recs, sr_next) {
+ rrec = (struct jrefrec *)srec->sr_rec;
+ if (ino_isat(rrec->jr_parent, rrec->jr_diroff, ino,
+ &recmode, &isdot) == 0)
+ continue;
+ ino_clrat(rrec->jr_parent, rrec->jr_diroff, ino);
+ break;
+ }
+ if (srec == NULL)
+ errx(1, "Directory %d name not found", ino);
+ }
/*
* If it's a directory with no real names pointing to it go ahead
* and truncate it. This will free any children.
*/
- if ((sino->si_mode & IFMT) == IFDIR &&
- nlink - sino->si_dotlinks == 0) {
+ if (mode == IFDIR && nlink - sino->si_dotlinks == 0) {
sino->si_nlink = nlink = 0;
/*
* Mark any .. links so they know not to free this inode
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