code: mafs

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updated document with the in-memory block contents

--- a/docs/mafs.ms

+++ b/docs/mafs.ms

@@ -50,6 +50,7 @@

 	Extents: box invis "Extents" "free blocks" with .nw at Datastructures.se + 0.5i,0

 	move 0.5*boxwid

 	Writer: box invis "writer" with .nw at Buffercache.ne + 0.4i,0

+	Inmemory: box invis "In-memory" "block contents" with .sw at Buffercache.n + 0.5i,0

 	down

 	move 0.5*boxwid

 	Disk: box "Disk" "blocks" height 1.5*boxht with .sw at Extents.se + 0.4i,0

@@ -63,6 +64,8 @@

 	line -> from Writer.s + 0,0.1i to Disk.n

 	line <-> from Extents.e to Disk.w

 	line <-> from Buffercache.s to Extents.n

+	line <-> from Buffercache.ne - 0,0.1i to Inmemory.sw + 0,0.1i

+	line <-> from Writer.n - 0,0.1i to Inmemory.s + 0.2i,0.1i

 .PE

 .sp

 .sp

@@ -111,16 +114,11 @@

 .nf

 struct Tag

 {

-	u64 path;	/* Qid.path, unique identifier of directory or file */

 	u8 type;	/* Tfree, Tmagic, Tdentry, Tdata, Tind\fIn\fR */

-	u8 dirty;	/* is 1, when being written to.

-				Identifies dirty data on a crash.

-				This byte position is denoted by the enum Nthdirty. */

+	u64 path;	/* Qid.path, unique identifier of directory or file */

 };

 .fi

 .sp

-A block in the process of being written is marked dirty (Tag.dirty = 1). After a successful write, the Tag.dirty is set to 0. This helps identify dirty blocks after a crash.

-.sp

 Every file or directory is represented on the disk by a directory entry (Dentry). A directory entry uses a block (Tag.type = Tdentry) and is uniquely identifiable by a Qid.

 .sp

 A file stores its contents in blocks with a Tag.type of Tdata. A directory holds the directory entries of it's children in blocks with a Tag.type of Tdentry.

@@ -688,7 +686,7 @@

 		u8	*xiobuf;	/* "real" buffer pointer */

 		Content *io;	/* cast'able to contents */

 	};

-	Ref	dirties;	/* number of dirty blocks yet to be written by the writer */

+	Ref	dirties;	/* number of versions of this block yet to be written by the writer */

 };

 .fi

 .sp

@@ -750,7 +748,7 @@

 .fi

 .sp

 .sp

-.ne 4

+.ne 10

 .ft B

 Asynchronous writes

 .ft R

binary files a/docs/mafs.pdf b/docs/mafs.pdf differ