[JFFS2] Debug code simplification, update TODO

Simplify the debugging code further. Update the TODO list Signed-off-by: Artem B. Bityutskiy <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]>
blinkosm · Nov 6, 2005 · 733802d · 733802d
1 parent b523b3b
commit 733802d
Show file tree

Hide file tree

Showing 14 changed files with 235 additions and 266 deletions.
diff --git a/fs/jffs2/TODO b/fs/jffs2/TODO
@@ -1,5 +1,11 @@
-$Id: TODO,v 1.10 2002/09/09 16:31:21 dwmw2 Exp $
+$Id: TODO,v 1.18 2005/09/22 11:24:56 dedekind Exp $
 
+ - support asynchronous operation -- add a per-fs 'reserved_space' count,
+   let each outstanding write reserve the _maximum_ amount of physical
+   space it could take. Let GC flush the outstanding writes because the
+   reservations will necessarily be pessimistic. With this we could even
+   do shared writable mmap, if we can have a fs hook for do_wp_page() to
+   make the reservation.
  - disable compression in commit_write()?
  - fine-tune the allocation / GC thresholds
  - chattr support - turning on/off and tuning compression per-inode
@@ -11,30 +17,24 @@ $Id: TODO,v 1.10 2002/09/09 16:31:21 dwmw2 Exp $
  - test, test, test
 
  - NAND flash support:
-	- flush_wbuf using GC to fill it, don't just pad.
-	- Deal with write errors. Data don't get lost - we just have to write 
-	  the affected node(s) out again somewhere else.
-	- make fsync flush only if actually required
-	- make sys_sync() work.
-	- reboot notifier
-	- timed flush of old wbuf
-	- fix magical second arg of jffs2_flush_wbuf(). Split into two or more functions instead.
-
+	- almost done :)
+	- use bad block check instead of the hardwired byte check
 
  - Optimisations:
-   - Stop GC from decompressing and immediately recompressing nodes which could
-     just be copied intact. (We now keep track of REF_PRISTINE flag. Easy now.)
-   - Furthermore, in the case where it could be copied intact we don't even need
-     to call iget() for it -- if we use (raw_node_raw->flash_offset & 2) as a flag
-     to show a node can be copied intact and it's _not_ in icache, we could just do
-     it, fix up the next_in_ino list and move on. We would need a way to find out
-     _whether_ it's in icache though -- if it's in icache we also need to do the 
-     fragment lists, etc. P'raps a flag or pointer in the jffs2_inode_cache could
-     help. (We have half of this now.)
+   - Split writes so they go to two separate blocks rather than just c->nextblock.
+	By writing _new_ nodes to one block, and garbage-collected REF_PRISTINE
+	nodes to a different one, we can separate clean nodes from those which
+	are likely to become dirty, and end up with blocks which are each far
+	closer to 100% or 0% clean, hence speeding up later GC progress dramatically.
    - Stop keeping name in-core with struct jffs2_full_dirent. If we keep the hash in 
      the full dirent, we only need to go to the flash in lookup() when we think we've
      got a match, and in readdir(). 
    - Doubly-linked next_in_ino list to allow us to free obsoleted raw_node_refs immediately?
    - Remove totlen from jffs2_raw_node_ref? Need to have totlen passed into
 	jffs2_mark_node_obsolete(). Can all callers work it out?
    - Remove size from jffs2_raw_node_frag. 
+
+dedekind:
+1. __jffs2_flush_wbuf() has a strange 'pad' parameter. Eliminate.
+2. get_sb()->build_fs()->scan() path... Why get_sb() removes scan()'s crap in
+   case of failure? scan() does not clean everything. Fix.
diff --git a/fs/jffs2/build.c b/fs/jffs2/build.c
@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: build.c,v 1.79 2005/09/07 11:21:57 havasi Exp $
+ * $Id: build.c,v 1.83 2005/09/21 15:52:33 dedekind Exp $
  *
  */
 
@@ -18,7 +18,8 @@
 #include <linux/mtd/mtd.h>
 #include "nodelist.h"
 
-static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *, struct jffs2_inode_cache *, struct jffs2_full_dirent **);
+static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *,
+		struct jffs2_inode_cache *, struct jffs2_full_dirent **);
 
 static inline struct jffs2_inode_cache *
 first_inode_chain(int *i, struct jffs2_sb_info *c)
@@ -46,38 +47,36 @@ next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c)
 	     ic = next_inode(&i, ic, (c)))
 
 
-static inline void jffs2_build_inode_pass1(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
+static inline void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
+					struct jffs2_inode_cache *ic)
 {
 	struct jffs2_full_dirent *fd;
 
-	D1(printk(KERN_DEBUG "jffs2_build_inode building directory inode #%u\n", ic->ino));
+	dbg_fsbuild("building directory inode #%u\n", ic->ino);
 
 	/* For each child, increase nlink */
 	for(fd = ic->scan_dents; fd; fd = fd->next) {
 		struct jffs2_inode_cache *child_ic;
 		if (!fd->ino)
 			continue;
 
-		/* XXX: Can get high latency here with huge directories */
+		/* we can get high latency here with huge directories */
 
 		child_ic = jffs2_get_ino_cache(c, fd->ino);
 		if (!child_ic) {
-			printk(KERN_NOTICE "Eep. Child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
+			dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
 				  fd->name, fd->ino, ic->ino);
 			jffs2_mark_node_obsolete(c, fd->raw);
 			continue;
 		}
 
 		if (child_ic->nlink++ && fd->type == DT_DIR) {
-			printk(KERN_NOTICE "Child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n", fd->name, fd->ino, ic->ino);
-			if (fd->ino == 1 && ic->ino == 1) {
-				printk(KERN_NOTICE "This is mostly harmless, and probably caused by creating a JFFS2 image\n");
-				printk(KERN_NOTICE "using a buggy version of mkfs.jffs2. Use at least v1.17.\n");
-			}
-			/* What do we do about it? */
+			JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n",
+				fd->name, fd->ino, ic->ino);
+			/* TODO: What do we do about it? */
 		}
-		D1(printk(KERN_DEBUG "Increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino));
-		/* Can't free them. We might need them in pass 2 */
+		dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino);
+		/* Can't free scan_dents so far. We might need them in pass 2 */
 	}
 }
 
@@ -94,6 +93,8 @@ static int jffs2_build_filesystem(struct jffs2_sb_info *c)
 	struct jffs2_full_dirent *fd;
 	struct jffs2_full_dirent *dead_fds = NULL;
 
+	dbg_fsbuild("build FS data structures\n");
+
 	/* First, scan the medium and build all the inode caches with
 	   lists of physical nodes */
 
@@ -103,60 +104,54 @@ static int jffs2_build_filesystem(struct jffs2_sb_info *c)
 	if (ret)
 		goto exit;
 
-	D1(printk(KERN_DEBUG "Scanned flash completely\n"));
+	dbg_fsbuild("scanned flash completely\n");
 	jffs2_dbg_dump_block_lists_nolock(c);
 
+	dbg_fsbuild("pass 1 starting\n");
 	c->flags |= JFFS2_SB_FLAG_BUILDING;
 	/* Now scan the directory tree, increasing nlink according to every dirent found. */
 	for_each_inode(i, c, ic) {
-		D1(printk(KERN_DEBUG "Pass 1: ino #%u\n", ic->ino));
-
-		D1(BUG_ON(ic->ino > c->highest_ino));
-
 		if (ic->scan_dents) {
 			jffs2_build_inode_pass1(c, ic);
 			cond_resched();
 		}
 	}
 
-	D1(printk(KERN_DEBUG "Pass 1 complete\n"));
+	dbg_fsbuild("pass 1 complete\n");
 
 	/* Next, scan for inodes with nlink == 0 and remove them. If
 	   they were directories, then decrement the nlink of their
 	   children too, and repeat the scan. As that's going to be
 	   a fairly uncommon occurrence, it's not so evil to do it this
 	   way. Recursion bad. */
-	D1(printk(KERN_DEBUG "Pass 2 starting\n"));
+	dbg_fsbuild("pass 2 starting\n");
 
 	for_each_inode(i, c, ic) {
-		D1(printk(KERN_DEBUG "Pass 2: ino #%u, nlink %d, ic %p, nodes %p\n", ic->ino, ic->nlink, ic, ic->nodes));
 		if (ic->nlink)
 			continue;
 
 		jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
 		cond_resched();
 	} 
 
-	D1(printk(KERN_DEBUG "Pass 2a starting\n"));
+	dbg_fsbuild("pass 2a starting\n");
 
 	while (dead_fds) {
 		fd = dead_fds;
 		dead_fds = fd->next;
 
 		ic = jffs2_get_ino_cache(c, fd->ino);
-		D1(printk(KERN_DEBUG "Removing dead_fd ino #%u (\"%s\"), ic at %p\n", fd->ino, fd->name, ic));
 
 		if (ic)
 			jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
 		jffs2_free_full_dirent(fd);
 	}
 
-	D1(printk(KERN_DEBUG "Pass 2 complete\n"));
+	dbg_fsbuild("pass 2a complete\n");
+	dbg_fsbuild("freeing temporary data structures\n");
 
 	/* Finally, we can scan again and free the dirent structs */
 	for_each_inode(i, c, ic) {
-		D1(printk(KERN_DEBUG "Pass 3: ino #%u, ic %p, nodes %p\n", ic->ino, ic, ic->nodes));
-
 		while(ic->scan_dents) {
 			fd = ic->scan_dents;
 			ic->scan_dents = fd->next;
@@ -167,8 +162,7 @@ static int jffs2_build_filesystem(struct jffs2_sb_info *c)
 	}
 	c->flags &= ~JFFS2_SB_FLAG_BUILDING;
 
-	D1(printk(KERN_DEBUG "Pass 3 complete\n"));
-	jffs2_dbg_dump_block_lists_nolock(c);
+	dbg_fsbuild("FS build complete\n");
 
 	/* Rotate the lists by some number to ensure wear levelling */
 	jffs2_rotate_lists(c);
@@ -189,24 +183,26 @@ static int jffs2_build_filesystem(struct jffs2_sb_info *c)
 	return ret;
 }
 
-static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, struct jffs2_full_dirent **dead_fds)
+static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
+					struct jffs2_inode_cache *ic,
+					struct jffs2_full_dirent **dead_fds)
 {
 	struct jffs2_raw_node_ref *raw;
 	struct jffs2_full_dirent *fd;
 
-	D1(printk(KERN_DEBUG "JFFS2: Removing ino #%u with nlink == zero.\n", ic->ino));
+	dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino);
 
 	raw = ic->nodes;
 	while (raw != (void *)ic) {
 		struct jffs2_raw_node_ref *next = raw->next_in_ino;
-		D1(printk(KERN_DEBUG "obsoleting node at 0x%08x\n", ref_offset(raw)));
+		dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw));
 		jffs2_mark_node_obsolete(c, raw);
 		raw = next;
 	}
 
 	if (ic->scan_dents) {
 		int whinged = 0;
-		D1(printk(KERN_DEBUG "Inode #%u was a directory which may have children...\n", ic->ino));
+		dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino);
 
 		while(ic->scan_dents) {
 			struct jffs2_inode_cache *child_ic;
@@ -216,21 +212,19 @@ static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, struct jf
 
 			if (!fd->ino) {
 				/* It's a deletion dirent. Ignore it */
-				D1(printk(KERN_DEBUG "Child \"%s\" is a deletion dirent, skipping...\n", fd->name));
+				dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name);
 				jffs2_free_full_dirent(fd);
 				continue;
 			}
-			if (!whinged) {
+			if (!whinged)
 				whinged = 1;
-				printk(KERN_NOTICE "Inode #%u was a directory with children - removing those too...\n", ic->ino);
-			}
 
-			D1(printk(KERN_DEBUG "Removing child \"%s\", ino #%u\n",
-				  fd->name, fd->ino));
+			dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino);
 
 			child_ic = jffs2_get_ino_cache(c, fd->ino);
 			if (!child_ic) {
-				printk(KERN_NOTICE "Cannot remove child \"%s\", ino #%u, because it doesn't exist\n", fd->name, fd->ino);
+				dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n",
+						fd->name, fd->ino);
 				jffs2_free_full_dirent(fd);
 				continue;
 			}
@@ -241,13 +235,13 @@ static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, struct jf
 			child_ic->nlink--;
 
 			if (!child_ic->nlink) {
-				D1(printk(KERN_DEBUG "Inode #%u (\"%s\") has now got zero nlink. Adding to dead_fds list.\n",
-					  fd->ino, fd->name));
+				dbg_fsbuild("inode #%u (\"%s\") has now got zero nlink, adding to dead_fds list.\n",
+					  fd->ino, fd->name);
 				fd->next = *dead_fds;
 				*dead_fds = fd;
 			} else {
-				D1(printk(KERN_DEBUG "Inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
-					  fd->ino, fd->name, child_ic->nlink));
+				dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
+					  fd->ino, fd->name, child_ic->nlink);
 				jffs2_free_full_dirent(fd);
 			}
 		}
@@ -295,20 +289,20 @@ static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c)
 	   trying to GC to make more space. It'll be a fruitless task */
 	c->nospc_dirty_size = c->sector_size + (c->flash_size / 100);
 
-	D1(printk(KERN_DEBUG "JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n",
-		  c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks));
-	D1(printk(KERN_DEBUG "Blocks required to allow deletion:    %d (%d KiB)\n",
-		  c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024));
-	D1(printk(KERN_DEBUG "Blocks required to allow writes:      %d (%d KiB)\n",
-		  c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024));
-	D1(printk(KERN_DEBUG "Blocks required to quiesce GC thread: %d (%d KiB)\n",
-		  c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024));
-	D1(printk(KERN_DEBUG "Blocks required to allow GC merges:   %d (%d KiB)\n",
-		  c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024));
-	D1(printk(KERN_DEBUG "Blocks required to GC bad blocks:     %d (%d KiB)\n",
-		  c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024));
-	D1(printk(KERN_DEBUG "Amount of dirty space required to GC: %d bytes\n",
-		  c->nospc_dirty_size));
+	dbg_fsbuild("JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n",
+		  c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks);
+	dbg_fsbuild("Blocks required to allow deletion:    %d (%d KiB)\n",
+		  c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024);
+	dbg_fsbuild("Blocks required to allow writes:      %d (%d KiB)\n",
+		  c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024);
+	dbg_fsbuild("Blocks required to quiesce GC thread: %d (%d KiB)\n",
+		  c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024);
+	dbg_fsbuild("Blocks required to allow GC merges:   %d (%d KiB)\n",
+		  c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024);
+	dbg_fsbuild("Blocks required to GC bad blocks:     %d (%d KiB)\n",
+		  c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024);
+	dbg_fsbuild("Amount of dirty space required to GC: %d bytes\n",
+		  c->nospc_dirty_size);
 } 
 
 int jffs2_do_mount_fs(struct jffs2_sb_info *c)
@@ -358,7 +352,7 @@ int jffs2_do_mount_fs(struct jffs2_sb_info *c)
 		return ret;
 
 	if (jffs2_build_filesystem(c)) {
-		D1(printk(KERN_DEBUG "build_fs failed\n"));
+		dbg_fsbuild("build_fs failed\n");
 		jffs2_free_ino_caches(c);
 		jffs2_free_raw_node_refs(c);
 #ifndef __ECOS

diff --git a/fs/jffs2/debug.c b/fs/jffs2/debug.c
@@ -7,14 +7,15 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: debug.c,v 1.10 2005/09/14 16:57:32 dedekind Exp $
+ * $Id: debug.c,v 1.11 2005/09/21 13:28:35 dedekind Exp $
  *
  */
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/pagemap.h>
 #include <linux/crc32.h>
 #include <linux/jffs2.h>
+#include <linux/mtd/mtd.h>
 #include "nodelist.h"
 #include "debug.h"