When running with soft updates, track the number of blocks and files

that are committed to being freed and reflect these blocks in the
counts returned by statfs (and thus also by the `df' command). This
change allows programs such as those that do news expiration to
know when to stop if they are trying to create a certain percentage
of free space. Note that this change does not solve the much harder
problem of making this to-be-freed space available to applications
that want it (thus on a nearly full filesystem, you may still
encounter out-of-space conditions even though the free space will
show up eventually). Hopefully this harder problem will be the
subject of a future enhancement.

9 files changed, 119 insertions, 11 deletions

diff --git a/sys/ufs/ffs/ffs_inode.c b/sys/ufs/ffs/ffs_inode.c
index 7a3c7ee..3af19b5 100644
--- a/sys/ufs/ffs/ffs_inode.c
+++ b/sys/ufs/ffs/ffs_inode.c
@@ -193,6 +193,8 @@ ffs_truncate(vp, length, flags, cred, p)
 			if ((error = VOP_FSYNC(ovp, cred, MNT_WAIT,
 			    p)) != 0)
 				return (error);
+			if (oip->i_flag & IN_SPACECOUNTED)
+				fs->fs_pendingblocks -= oip->i_blocks;
 		} else {
 #ifdef QUOTA
 			(void) chkdq(oip, -oip->i_blocks, NOCRED, 0);
diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 2b88fe6..d950301 100644
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -57,6 +57,7 @@
 #include <sys/malloc.h>
 #include <sys/mount.h>
 #include <sys/proc.h>
+#include <sys/stat.h>
 #include <sys/syslog.h>
 #include <sys/vnode.h>
 #include <sys/conf.h>
@@ -1725,7 +1726,7 @@ softdep_setup_freeblocks(ip, length)
 
 	fs = ip->i_fs;
 	if (length != 0)
-		panic("softde_setup_freeblocks: non-zero length");
+		panic("softdep_setup_freeblocks: non-zero length");
 	MALLOC(freeblks, struct freeblks *, sizeof(struct freeblks),
 		M_FREEBLKS, M_SOFTDEP_FLAGS|M_ZERO);
 	freeblks->fb_list.wk_type = D_FREEBLKS;
@@ -1747,6 +1748,13 @@ softdep_setup_freeblocks(ip, length)
 	ip->i_blocks = 0;
 	ip->i_size = 0;
 	/*
+	 * If the file was removed, then the space being freed was
+	 * accounted for then (see softdep_filereleased()). If the
+	 * file is merely being truncated, then we account for it now.
+	 */
+	if ((ip->i_flag & IN_SPACECOUNTED) == 0)
+		fs->fs_pendingblocks += freeblks->fb_chkcnt;
+	/*
 	 * Push the zero'ed inode to to its disk buffer so that we are free
 	 * to delete its dependencies below. Once the dependencies are gone
 	 * the buffer can be safely released.
@@ -1986,6 +1994,8 @@ softdep_freefile(pvp, ino, mode)
 	freefile->fx_oldinum = ino;
 	freefile->fx_devvp = ip->i_devvp;
 	freefile->fx_mnt = ITOV(ip)->v_mount;
+	if ((ip->i_flag & IN_SPACECOUNTED) == 0)
+		ip->i_fs->fs_pendinginodes += 1;
 
 	/*
 	 * If the inodedep does not exist, then the zero'ed inode has
@@ -2118,6 +2128,7 @@ handle_workitem_freeblocks(freeblks, flags)
 		    baselbns[level], &blocksreleased)) == 0)
 			allerror = error;
 		ffs_blkfree(&tip, bn, fs->fs_bsize);
+		fs->fs_pendingblocks -= nblocks;
 		blocksreleased += nblocks;
 	}
 	/*
@@ -2128,6 +2139,7 @@ handle_workitem_freeblocks(freeblks, flags)
 			continue;
 		bsize = blksize(fs, &tip, i);
 		ffs_blkfree(&tip, bn, bsize);
+		fs->fs_pendingblocks -= btodb(bsize);
 		blocksreleased += btodb(bsize);
 	}
 	/*
@@ -2229,6 +2241,7 @@ indir_trunc(ip, dbn, level, lbn, countp)
 				allerror = error;
 		}
 		ffs_blkfree(ip, nb, fs->fs_bsize);
+		fs->fs_pendingblocks -= nblocks;
 		*countp += nblocks;
 	}
 	bp->b_flags |= B_INVAL | B_NOCACHE;
@@ -2780,6 +2793,47 @@ softdep_change_linkcnt(ip)
 }
 
 /*
+ * Called when the effective link count and the reference count
+ * on an inode drops to zero. At this point there are no names
+ * referencing the file in the filesystem and no active file
+ * references. The space associated with the file will be freed
+ * as soon as the necessary soft dependencies are cleared.
+ */
+void
+softdep_releasefile(ip)
+	struct inode *ip;	/* inode with the zero effective link count */
+{
+	struct inodedep *inodedep;
+
+	if (ip->i_effnlink > 0)
+		panic("softdep_filerelease: file still referenced");
+	/*
+	 * We may be called several times as the real reference count
+	 * drops to zero. We only want to account for the space once.
+	 */
+	if (ip->i_flag & IN_SPACECOUNTED)
+		return;
+	/*
+	 * We have to deactivate a snapshot otherwise copyonwrites may
+	 * add blocks and the cleanup may remove blocks after we have
+	 * tried to account for them.
+	 */
+	if ((ip->i_flags & SF_SNAPSHOT) != 0)
+		ffs_snapremove(ITOV(ip));
+	/*
+	 * If we are tracking an nlinkdelta, we have to also remember
+	 * whether we accounted for the freed space yet.
+	 */
+	ACQUIRE_LOCK(&lk);
+	if ((inodedep_lookup(ip->i_fs, ip->i_number, 0, &inodedep)))
+		inodedep->id_state |= SPACECOUNTED;
+	FREE_LOCK(&lk);
+	ip->i_fs->fs_pendingblocks += ip->i_blocks;
+	ip->i_fs->fs_pendinginodes += 1;
+	ip->i_flag |= IN_SPACECOUNTED;
+}
+
+/*
  * This workitem decrements the inode's link count.
  * If the link count reaches zero, the file is removed.
  */
@@ -2905,6 +2959,7 @@ handle_workitem_freefile(freefile)
 	tip.i_devvp = freefile->fx_devvp;
 	tip.i_dev = freefile->fx_devvp->v_rdev;
 	tip.i_fs = fs;
+	fs->fs_pendinginodes -= 1;
 	if ((error = ffs_freefile(&tip, freefile->fx_oldinum, freefile->fx_mode)) != 0)
 		softdep_error("handle_workitem_freefile", error);
 	WORKITEM_FREE(freefile, D_FREEFILE);
@@ -3779,6 +3834,8 @@ softdep_load_inodeblock(ip)
 		return;
 	}
 	ip->i_effnlink -= inodedep->id_nlinkdelta;
+	if (inodedep->id_state & SPACECOUNTED)
+		ip->i_flag |= IN_SPACECOUNTED;
 	FREE_LOCK(&lk);
 }
 
diff --git a/sys/ufs/ffs/ffs_softdep_stub.c b/sys/ufs/ffs/ffs_softdep_stub.c
index 95c9475..3460b7c 100644
--- a/sys/ufs/ffs/ffs_softdep_stub.c
+++ b/sys/ufs/ffs/ffs_softdep_stub.c
@@ -270,6 +270,15 @@ int
 softdep_slowdown(vp)
 	struct vnode *vp;
 {
+
 	panic("softdep_slowdown called");
 }
+
+void
+softdep_releasefile(ip)
+	struct inode *ip;	/* inode with the zero effective link count */
+{
+
+	panic("softdep_releasefile called");
+}
 #endif	/* SOFTUPDATES not configured in */
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index b1fb0cf..04ba155 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -192,6 +192,14 @@ ffs_mount(mp, path, data, ndp, p)
 				vn_finished_write(mp);
 				return (error);
 			}
+			if (fs->fs_pendingblocks != 0 ||
+			    fs->fs_pendinginodes != 0) {
+				printf("%s: update error: blocks %d files %d\n",
+				    fs->fs_fsmnt, fs->fs_pendingblocks,
+				    fs->fs_pendinginodes);
+				fs->fs_pendingblocks = 0;
+				fs->fs_pendinginodes = 0;
+			}
 			fs->fs_ronly = 1;
 			if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0)
 				fs->fs_clean = 1;
@@ -433,6 +441,12 @@ ffs_reload(mp, cred, p)
 		fs->fs_avgfilesize = AVFILESIZ;	/* XXX */
 	if (fs->fs_avgfpdir <= 0)		/* XXX */
 		fs->fs_avgfpdir = AFPDIR;	/* XXX */
+	if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
+		printf("%s: reload pending error: blocks %d files %d\n",
+		    fs->fs_fsmnt, fs->fs_pendingblocks, fs->fs_pendinginodes);
+		fs->fs_pendingblocks = 0;
+		fs->fs_pendinginodes = 0;
+	}
 
 	/*
 	 * Step 3: re-read summary information from disk.
@@ -609,6 +623,18 @@ ffs_mountfs(devvp, mp, p, malloctype)
 			error = EPERM;
 			goto out;
 		}
+		if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
+			printf("%s: lost blocks %d files %d\n", fs->fs_fsmnt,
+			    fs->fs_pendingblocks, fs->fs_pendinginodes);
+			fs->fs_pendingblocks = 0;
+			fs->fs_pendinginodes = 0;
+		}
+	}
+	if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
+		printf("%s: mount pending error: blocks %d files %d\n",
+		    fs->fs_fsmnt, fs->fs_pendingblocks, fs->fs_pendinginodes);
+		fs->fs_pendingblocks = 0;
+		fs->fs_pendinginodes = 0;
 	}
 	/* XXX updating 4.2 FFS superblocks trashes rotational layout tables */
 	if (fs->fs_postblformat == FS_42POSTBLFMT && !ronly) {
@@ -826,6 +852,12 @@ ffs_unmount(mp, mntflags, p)
 		fs->fs_cgsize = fs->fs_sparecon[0];
 		fs->fs_sparecon[0] = 0;
 	}
+	if (fs->fs_pendingblocks != 0 || fs->fs_pendinginodes != 0) {
+		printf("%s: unmount pending error: blocks %d files %d\n",
+		    fs->fs_fsmnt, fs->fs_pendingblocks, fs->fs_pendinginodes);
+		fs->fs_pendingblocks = 0;
+		fs->fs_pendinginodes = 0;
+	}
 	if (fs->fs_ronly == 0) {
 		fs->fs_clean = fs->fs_flags & (FS_UNCLEAN|FS_NEEDSFSCK) ? 0 : 1;
 		error = ffs_sbupdate(ump, MNT_WAIT);
@@ -923,10 +955,11 @@ ffs_statfs(mp, sbp, p)
 	sbp->f_iosize = fs->fs_bsize;
 	sbp->f_blocks = fs->fs_dsize;
 	sbp->f_bfree = fs->fs_cstotal.cs_nbfree * fs->fs_frag +
-		fs->fs_cstotal.cs_nffree;
-	sbp->f_bavail = freespace(fs, fs->fs_minfree);
+	    fs->fs_cstotal.cs_nffree + dbtofsb(fs, fs->fs_pendingblocks);
+	sbp->f_bavail = freespace(fs, fs->fs_minfree) +
+	    dbtofsb(fs, fs->fs_pendingblocks);
 	sbp->f_files =  fs->fs_ncg * fs->fs_ipg - ROOTINO;
-	sbp->f_ffree = fs->fs_cstotal.cs_nifree;
+	sbp->f_ffree = fs->fs_cstotal.cs_nifree + fs->fs_pendinginodes;
 	if (sbp != &mp->mnt_stat) {
 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
 		bcopy((caddr_t)mp->mnt_stat.f_mntonname,
diff --git a/sys/ufs/ffs/fs.h b/sys/ufs/ffs/fs.h
index b9cab9a..0a3ad96 100644
--- a/sys/ufs/ffs/fs.h
+++ b/sys/ufs/ffs/fs.h
@@ -295,7 +295,9 @@ struct fs {
 	int32_t	 fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
 	int32_t	 fs_avgfilesize;	/* expected average file size */
 	int32_t	 fs_avgfpdir;		/* expected # of files per directory */
-	int32_t	 fs_sparecon[28];	/* reserved for future constants */
+	int32_t	 fs_sparecon[26];	/* reserved for future constants */
+	int32_t	 fs_pendingblocks;	/* blocks in process of being freed */
+	int32_t	 fs_pendinginodes;	/* inodes in process of being freed */
 	int32_t	 fs_contigsumsize;	/* size of cluster summary array */ 
 	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
 	int32_t	 fs_inodefmt;		/* format of on-disk inodes */
diff --git a/sys/ufs/ffs/softdep.h b/sys/ufs/ffs/softdep.h
index cf9cac8..9a158c5 100644
--- a/sys/ufs/ffs/softdep.h
+++ b/sys/ufs/ffs/softdep.h
@@ -82,8 +82,10 @@
  * data structure is frozen from further change until its dependencies
  * have been completed and its resources freed after which it will be
  * discarded. The IOSTARTED flag prevents multiple calls to the I/O
- * start routine from doing multiple rollbacks. The ONWORKLIST flag
- * shows whether the structure is currently linked onto a worklist.
+ * start routine from doing multiple rollbacks. The SPACECOUNTED flag
+ * says that the files space has been accounted to the pending free
+ * space count. The ONWORKLIST flag shows whether the structure is
+ * currently linked onto a worklist.
  */
 #define	ATTACHED	0x0001
 #define	UNDONE		0x0002
@@ -95,6 +97,7 @@
 #define DIRCHG		0x0080
 #define GOINGAWAY	0x0100
 #define IOSTARTED	0x0200
+#define SPACECOUNTED	0x0400
 #define ONWORKLIST	0x8000
 
 #define	ALLCOMPLETE	(ATTACHED | COMPLETE | DEPCOMPLETE)
diff --git a/sys/ufs/ufs/inode.h b/sys/ufs/ufs/inode.h
index 3e7c67d..0fdaee2 100644
--- a/sys/ufs/ufs/inode.h
+++ b/sys/ufs/ufs/inode.h
@@ -125,10 +125,9 @@ struct inode {
 #define	IN_UPDATE	0x0004		/* Modification time update request. */
 #define	IN_MODIFIED	0x0008		/* Inode has been modified. */
 #define	IN_RENAME	0x0010		/* Inode is being renamed. */
-#define	IN_SHLOCK	0x0020		/* File has shared lock. */
-#define	IN_EXLOCK	0x0040		/* File has exclusive lock. */
-#define	IN_HASHED	0x0080		/* Inode is on hash list */
-#define	IN_LAZYMOD	0x0100		/* Modified, but don't write yet. */
+#define	IN_HASHED	0x0020		/* Inode is on hash list */
+#define	IN_LAZYMOD	0x0040		/* Modified, but don't write yet. */
+#define	IN_SPACECOUNTED	0x0080		/* Blocks to be freed in free count. */
 
 #ifdef _KERNEL
 /*
diff --git a/sys/ufs/ufs/ufs_extern.h b/sys/ufs/ufs/ufs_extern.h
index 2a98e9b..e08ee8d 100644
--- a/sys/ufs/ufs/ufs_extern.h
+++ b/sys/ufs/ufs/ufs_extern.h
@@ -104,6 +104,7 @@ void	softdep_setup_remove __P((struct buf *,struct inode *, struct inode *,
 void	softdep_setup_directory_change __P((struct buf *, struct inode *,
 	    struct inode *, long, int));
 void	softdep_change_linkcnt __P((struct inode *));
+void	softdep_releasefile __P((struct inode *));
 int	softdep_slowdown __P((struct vnode *));
 
 #endif /* !_UFS_UFS_EXTERN_H_ */
diff --git a/sys/ufs/ufs/ufs_inode.c b/sys/ufs/ufs/ufs_inode.c
index d4ed8b3..4f4638d 100644
--- a/sys/ufs/ufs/ufs_inode.c
+++ b/sys/ufs/ufs/ufs_inode.c
@@ -77,6 +77,8 @@ ufs_inactive(ap)
 	 */
 	if (ip->i_mode == 0)
 		goto out;
+	if (ip->i_effnlink == 0 && DOINGSOFTDEP(vp))
+		softdep_releasefile(ip);
 	if (ip->i_nlink <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
 		(void) vn_write_suspend_wait(vp, NULL, V_WAIT);
 #ifdef QUOTA