[patch] reiser4progs: Handle unprepped items by fsck

[Edward Shishkin <edward.shishkin@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 314 bytes --]

Hello everyone. This patch fixes the problem (segmentation fault)
in fsck reported by Bringfried Stecklum and Jonáš Vidra:

http://marc.info/?l=reiserfs-devel&m=126936575206572&w=2

However, the source of the problem in the kernel (data loss by
cryptcompress file plugin) is not yet eliminated.

Thanks,
Edward.

[-- Attachment #2: reiser4progs-fsck-handle-unprepped-cluster.patch --]
[-- Type: text/x-patch, Size: 12273 bytes --]

. Handle orphan "unprepped" clusters;
. Don't repair the value of cluster shift in ctail item
  in all circumstances. If cluster shift is wrong, then
  remove the whole cluster.

Signed-off-by: Edward Shishkin <edward.shishkin@gmail.com>
---
 plugin/object/ccreg40/ccreg40.c        |   12 +-
 plugin/object/ccreg40/ccreg40.h        |    9 +
 plugin/object/ccreg40/ccreg40_repair.c |  196 +++++++++++++++++----------------
 3 files changed, 121 insertions(+), 96 deletions(-)

--- reiser4progs-1.0.7.orig/plugin/object/ccreg40/ccreg40.h
+++ reiser4progs-1.0.7/plugin/object/ccreg40/ccreg40.h
@@ -11,6 +11,12 @@
 #include "reiser4/plugin.h"
 #include "plugin/object/obj40/obj40.h"
 
+#define MIN_VALID_CLUSTER_SHIFT (0xc)
+#define MAX_VALID_CLUSTER_SHIFT (0x10)
+#define UNPREPPED_CLUSTER_SHIFT (0xff)
+
+#define ccreg40_cloff(off, size) ((off) & ((size) - 1))
+
 #define ccreg40_clstart(off, size) ((off) & ~((size) - 1))
 
 #define ccreg40_clnext(off, size) (ccreg40_clstart(off, size) + (size))
@@ -22,7 +28,8 @@ extern errno_t ccreg40_check_struct(reis
 				    place_func_t func,
 				    void *data, uint8_t mode);
 
-extern uint32_t ccreg40_get_cluster_size(reiser4_place_t *place);
+extern errno_t ccreg40_get_cluster_shift(reiser4_place_t *place,
+					 uint8_t *shift);
 
 extern errno_t ccreg40_set_cluster_size(reiser4_place_t *place, 
 					uint32_t cluster);
--- reiser4progs-1.0.7.orig/plugin/object/ccreg40/ccreg40_repair.c
+++ reiser4progs-1.0.7/plugin/object/ccreg40/ccreg40_repair.c
@@ -25,80 +25,81 @@ typedef struct ccreg40_hint {
 	uint64_t seek;       /* expected offset for lookup */
 	uint64_t found;      /* what has been really found */
 	uint64_t maxreal;    /* maximal (key) offset in the found item */
-
-	/* Bytes all clusters takes on disk. */
-	uint32_t bytes;
 	uint64_t sdsize;
+	/* The following two fields are to delete wrecks of a disk cluster */
+	uint64_t cut_from;   /* offset to cut from */
+	uint32_t cut_size;   /* how many bytes to cut */
+	uint32_t clsize;
+	/* Total number of units in a disk cluster */
+	uint32_t bytes;
 	uint32_t adler;
 	uint8_t mode;
-
-	/* If a hole is detected. */
+	/* Indicates if cluster has a hole in key space */
 	uint8_t hole;
-	
 	/* The cluster size & the buffer for the data. */
 	uint8_t data[64 * 1024];
-	uint64_t clstart;
-	uint32_t clsize;
 } ccreg40_hint_t;
 
 static errno_t ccreg40_check_item(reiser4_object_t *cc, void *data) {
 	ccreg40_hint_t *hint = (ccreg40_hint_t *)data;
-	uint32_t clsize;
-	errno_t res = 0;
-		
+	uint8_t shift;
+	errno_t result;
+
 	hint->found = objcall(&cc->body.key, get_offset);
 	hint->maxreal = obj40_place_maxreal(&cc->body);
 	
 	aal_assert("vpf-1871", hint->maxreal >= hint->found);
 	aal_assert("vpf-1872", hint->seek <= hint->found);
 	
-	/* Check the item plugin. */
+	/* check item plugin */
 	if (cc->body.plug != reiser4_psctail(cc)) {
-		fsck_mess("The file [%s] (%s), node [%llu], item "
-			  "[%u]: item of the illegal plugin (%s) "
-			  "with the key of this object found.%s",
-			  print_inode(obj40_core, &cc->info.object),
-			  reiser4_psobj(cc)->p.label, place_blknr(&cc->body),
-			  cc->body.pos.item, cc->body.plug->p.label, 
-			  hint->mode == RM_BUILD ? " Removed." : "");
-		
-		return hint->mode == RM_BUILD ? -ESTRUCT : RE_FATAL;
+		fsck_mess("Found item of illegal plugin (%s) "
+			  "with the key of this object ",
+			  cc->body.plug->p.label);
+		goto fatal;
 	}
-	
-	/* Check the shift. */
-	clsize = ccreg40_get_cluster_size(&cc->body);
-	
-	if (hint->clsize != clsize) {
-		fsck_mess("The file [%s] (%s), node [%llu], item [%u]: item "
-			  "of the wrong cluster size (%d) found, Should be "
-			  "(%d).%s", print_inode(obj40_core, &cc->info.object),
-			  reiser4_psobj(cc)->p.label, place_blknr(&cc->body),
-			  cc->body.pos.item, clsize, hint->clsize, 
-			  hint->mode != RM_CHECK ? " Fixed." : "");
-
-		/* Just fix the shift if wrong. */
-		if (hint->mode == RM_CHECK) {
-			res |= RE_FIXABLE;
-		} else {
-			ccreg40_set_cluster_size(&cc->body, hint->clsize);
-		}
+	/* check cluster shift. */
+	result = ccreg40_get_cluster_shift(&cc->body, &shift);
+	if (result < 0)
+		return result;
+	if (shift == UNPREPPED_CLUSTER_SHIFT) {
+		fsck_mess("Found unprepped disk cluster ");
+		goto fatal;
+	}
+	if (shift < MIN_VALID_CLUSTER_SHIFT ||
+	    shift > MAX_VALID_CLUSTER_SHIFT ||
+	    shift != aal_log2(hint->clsize)) {
+		fsck_mess("Found item with wrong cluster shift %d, "
+			  "should be %d", shift, aal_log2(hint->clsize));
+		goto fatal;
+	}
+	if (hint->seek &&
+	    !ccreg40_clsame(hint->prev_found, hint->found, hint->clsize) &&
+	    ccreg40_cloff(hint->found, hint->clsize) != 0){
+		fsck_mess("Found item of lenght (%llu) which has wrong "
+			  "offset %llu, should be a multiple of logical "
+			  "cluster size ",
+			  hint->maxreal - hint->found + 1, hint->found);
+		goto fatal;
 	}
-	
 	if (!ccreg40_clsame(hint->found, hint->maxreal, hint->clsize)) {
-		/* The item covers the cluster border. Delete it. */
-		fsck_mess("The file [%s] (%s), node [%llu], item [%u]: "
-			  "item of the lenght (%llu) found, it cannot "
-			  "contain data of 2 clusters.%s", 
-			  print_inode(obj40_core, &cc->info.object),
-			  reiser4_psobj(cc)->p.label, 
-			  place_blknr(&cc->body), cc->body.pos.item,
-			  hint->maxreal - hint->found + 1, 
-			  hint->mode == RM_BUILD ? " Removed." : "");
-		
-		return hint->mode == RM_BUILD ? -ESTRUCT : RE_FATAL;
+		fsck_mess("Found item of length %llu and offset %llu, "
+			  "which contains logical cluster boundary ",
+			  hint->maxreal - hint->found + 1, hint->found);
+		goto fatal;
 	}
-	
-	return res;
+	return 0;
+ fatal:
+	fsck_mess("(file [%s] (%s), node [%llu], item [%u]). %s",
+		  print_inode(obj40_core, &cc->info.object),
+		  reiser4_psobj(cc)->p.label,
+		  place_blknr(&cc->body),
+		  cc->body.pos.item,
+		  hint->mode == RM_BUILD ? " Removed." : "");
+	hint->cut_from = hint->found;
+	hint->cut_size = hint->maxreal - hint->found + 1;
+
+	return hint->mode == RM_BUILD ? -ESTRUCT : RE_FATAL;
 }
 
 static int64_t ccreg40_read_item(reiser4_place_t *place, ccreg40_hint_t *hint) {
@@ -133,23 +134,21 @@ static errno_t ccreg40_check_crc(ccreg40
 	return adler == disk ? 0 : RE_FATAL;
 }
 
+/*
+ * Read a found item to the stream.
+ * Check a checksum, if the previous iteration completed a disk cluster.
+ */
 static errno_t ccreg40_check_cluster(reiser4_object_t *cc, 
 				     ccreg40_hint_t *hint,
 				     uint8_t mode) 
 {
-	errno_t result;
+	errno_t result = 0;
 	errno_t res;
-	int start;
-	uint32_t lcl_size;
-
-	result = 0;
-	/* true, if the found item is the
-	   first one in the disk cluster */
-	start = (ccreg40_clstart(hint->found, hint->clsize) == hint->found);
+	uint32_t lcl_bytes;
 
 	if ((cc->body.plug == NULL) ||
-	    (hint->seek && start) ||
-	    !ccreg40_clsame(hint->prev_found, hint->found, hint->clsize)) {
+	    (hint->seek != 0 &&
+	     !ccreg40_clsame(hint->prev_found, hint->found, hint->clsize))) {
 		/* Cluster is over */
 
 		if (hint->prev_found > hint->sdsize) {
@@ -158,31 +157,32 @@ static errno_t ccreg40_check_cluster(rei
 			result = RE_FATAL;
 
 			/* set offset of the cluster to be deleted. */
-			hint->clstart = ccreg40_clstart(hint->prev_found,
-							hint->clsize);
+			hint->cut_from = ccreg40_clstart(hint->prev_found,
+							 hint->clsize);
 			fsck_mess("The file [%s] (%s): the cluster at [%llu] "
 				  "offset %u bytes long is orphan.%s",
 				  print_inode(obj40_core, &cc->info.object),
-				  reiser4_psobj(cc)->p.label, hint->clstart,
+				  reiser4_psobj(cc)->p.label, hint->cut_from,
 				  hint->clsize, hint->mode != RM_CHECK ?
 				  " Removed." : "");
 		}
 		/**
-		 * If there still is a hole in the logical cluster,
-		 * then check a checksum (no hole means no checksum)
+		 * If there still is a hole in the keyspace, then
+		 * check a checksum (no such hole means that no
+		 * checksum was appended)
 		 */
-		else if (hint->hole && ccreg40_check_crc(hint)) {
+		else if (hint->bytes && hint->hole && ccreg40_check_crc(hint)) {
 			/* wrong checksum */
 			hint->bytes = 0;
 			result = RE_FATAL;
 
 			/* set offset of the cluster to be deleted. */
-			hint->clstart = ccreg40_clstart(hint->prev_found,
-							hint->clsize);
+			hint->cut_from = ccreg40_clstart(hint->prev_found,
+							 hint->clsize);
 			fsck_mess("The file [%s] (%s): the cluster at [%llu] "
 				  "offset %u bytes long is corrupted.%s",
 				  print_inode(obj40_core, &cc->info.object),
-				  reiser4_psobj(cc)->p.label, hint->clstart,
+				  reiser4_psobj(cc)->p.label, hint->cut_from,
 				  hint->clsize, hint->mode != RM_CHECK ? 
 				  " Removed." : "");
 		}
@@ -192,16 +192,13 @@ static errno_t ccreg40_check_cluster(rei
 		hint->adler = 0;
 
 		if (!cc->body.plug)
+			/* finish with this object */
 			return result;
 
 		/* Update the cluster data. */
 		aal_memset(hint->data, 0, hint->clsize);
 	}
-	
 	/* An item found. */
-	aal_assert("edward-1",
-		   ccreg40_clstart(hint->found, hint->clsize) ==
-		   ccreg40_clstart(hint->maxreal, hint->clsize));
 
 	if ((res = ccreg40_read_item(&cc->body, hint)))
 		return res;
@@ -209,16 +206,19 @@ static errno_t ccreg40_check_cluster(rei
 	hint->prev_found = hint->found;
 	hint->bytes += objcall(&cc->body, object->bytes);
 	/**
-	 * Calculate a size of logical cluster
-	 * and figure out, if there is a hole
-	 * for the found items in the logical cluster.
+	 * Calculate actual number of file's bytes in the
+	 * logical cluster and figure out, if corresponding
+	 * disk cluster has a hole in key space.
+	 *
+	 * We need this to figure out if disk cluster contains
+	 * appended checksum.
 	 */
-	lcl_size = 0;
+	lcl_bytes = 0;
 	if (ccreg40_clsame(hint->found, hint->sdsize - 1, hint->clsize))
-		lcl_size = hint->sdsize % hint->clsize;
-	if (lcl_size == 0)
-		lcl_size = hint->clsize;
-	hint->hole = (hint->bytes != lcl_size);
+		lcl_bytes = hint->sdsize % hint->clsize;
+	if (lcl_bytes == 0)
+		lcl_bytes = hint->clsize;
+	hint->hole = (hint->bytes != lcl_bytes);
 
 	return result;
 }
@@ -256,8 +256,23 @@ errno_t ccreg40_check_struct(reiser4_obj
 		/* Get next item. */
 		lookup = obj40_check_item(cc, ccreg40_check_item, NULL, &hint);
 		
-		if (repair_error_fatal(lookup))
-			return lookup;
+		if (repair_error_fatal(lookup)) {
+			    if ((lookup & RE_FATAL) && mode == RM_BUILD) {
+				    /*
+				     * Delete item found in this iteration
+				     */
+				    res &= ~RE_FATAL;
+				    res |= obj40_cut(cc, &trans, hint.cut_from,
+						     hint.cut_size, NULL, NULL);
+				    if (res < 0)
+					    return res;
+				    hint.seek = hint.maxreal + 1;
+				    obj40_seek(cc, hint.seek);
+				    continue;
+			    }
+			    else
+				    return lookup;
+		}
 		else if (lookup == ABSENT)
 			cc->body.plug = NULL;
 		
@@ -267,16 +282,17 @@ errno_t ccreg40_check_struct(reiser4_obj
 				"registered yet.", print_key(obj40_core, 
 							     &info->object));
 		}
-		
+		/* check cluster found in previous iteration */
 		if ((res |= ccreg40_check_cluster(cc, &hint, mode)) < 0)
 			return res;
 
 		if (res & RE_FATAL) {
-			/* Delete the whole cluster. */
-			
+			/*
+			 * Delete cluster found in previous iteration
+			 */
 			if (mode == RM_BUILD) {
 				res &= ~RE_FATAL;
-				res |= obj40_cut(cc, &trans, hint.clstart,
+				res |= obj40_cut(cc, &trans, hint.cut_from,
 						 hint.clsize, NULL, NULL);
 				if (res < 0)
 					return res;
--- reiser4progs-1.0.7.orig/plugin/object/ccreg40/ccreg40.c
+++ reiser4progs-1.0.7/plugin/object/ccreg40/ccreg40.c
@@ -8,7 +8,7 @@
 #include "ccreg40.h"
 #include "plugin/object/obj40/obj40_repair.h"
 
-uint32_t ccreg40_get_cluster_size(reiser4_place_t *place) {
+errno_t ccreg40_get_cluster_shift(reiser4_place_t *place, uint8_t *shift) {
 	trans_hint_t hint;
 	ctail_hint_t chint;
 	
@@ -17,10 +17,12 @@ uint32_t ccreg40_get_cluster_size(reiser
 	hint.specific = &chint;
 	hint.count = 1;
 
-	if (objcall(place, object->fetch_units, &hint) != 1)
-		return MAX_UINT32;
-	
-	return 1 << chint.shift;
+	if (objcall(place, object->fetch_units, &hint) != 1) {
+	        aal_error("Can not extract cluster shift.");
+		return -EINVAL;
+	}
+	*shift = chint.shift;
+	return 0;
 }
 
 errno_t ccreg40_set_cluster_size(reiser4_place_t *place, uint32_t cluster) {