Starting NXFFS packing logic

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3553 42af7a65-404d-4744-a932-0658087f49c3

4 files changed, 353 insertions, 133 deletions

diff --git a/nuttx/fs/nxffs/nxffs.h b/nuttx/fs/nxffs/nxffs.h
index 48311f3ec..51c7d7a3d 100644
--- a/nuttx/fs/nxffs/nxffs.h
+++ b/nuttx/fs/nxffs/nxffs.h
@@ -239,6 +239,15 @@ struct nxffs_entry_s
   uint32_t                  datlen;    /* Length of inode data */
 };
 
+/* This structure describes int in-memory representation of the data block */
+
+struct nxffs_blkentry_s
+{
+  off_t                     hoffset;  /* Offset to the block data header */
+  uint16_t                  datlen;   /* Length of data following the header */
+  uint16_t                  foffset;  /* Offset to start of data */
+};
+
 /* This structure describes the state of one open file.  This structure
  * is protected by the volume semaphore.
  */
@@ -285,6 +294,7 @@ struct nxffs_volume_s
   off_t                     cblock;    /* Starting block number in cache */
   FAR struct nxffs_ofile_s *ofiles;    /* A singly-linked list of open files */
   FAR uint8_t              *cache;     /* Allocated erase block */
+  FAR uint8_t              *pack;      /* Extra I/O block buffer to support packing */
 };
 
 /* This structure describes the state of the blocks on the NXFFS volume */
@@ -769,7 +779,6 @@ extern FAR struct nxffs_ofile_s *nxffs_findofile(FAR struct nxffs_volume_s *volu
  *   volume->froffset - Updated offset to the first free FLASH block after
  *     the reserved memory.
  *
- *
  * Defined in nxffs_write.c
  *
  ****************************************************************************/
@@ -777,6 +786,28 @@ extern FAR struct nxffs_ofile_s *nxffs_findofile(FAR struct nxffs_volume_s *volu
 extern int nxffs_wrreserve(FAR struct nxffs_volume_s *volume, size_t size);
 
 /****************************************************************************
+ * Name: nxffs_nextblock
+ *
+ * Description:
+ *   Search for the next valid data block starting at the provided
+ *   FLASH offset.
+ *
+ * Input Parameters:
+ *   volume - Describes the NXFFS volume.
+ *   datlen  - A memory location to return the data block length.
+ *  
+ * Returned Value:
+ *   Zero is returned on success. Otherwise, a negated errno is returned
+ *   that indicates the nature of the failure.
+ *
+ * Defined in nxffs_read.c
+ *
+ ****************************************************************************/
+
+extern int nxffs_nextblock(FAR struct nxffs_volume_s *volume, off_t offset,
+                           FAR struct nxffs_blkentry_s *blkentry);
+
+/****************************************************************************
  * Name: nxffs_wrverify
  *
  * Description:
@@ -814,6 +845,8 @@ extern int nxffs_wrreserve(FAR struct nxffs_volume_s *volume, size_t size);
  *     position.
  *   volume->froffset - Updated offset to the first free FLASH block.
  *
+ * Defined in nxffs_write.c
+ *
  ****************************************************************************/
 
 extern int nxffs_wrverify(FAR struct nxffs_volume_s *volume, size_t size);
diff --git a/nuttx/fs/nxffs/nxffs_initialize.c b/nuttx/fs/nxffs/nxffs_initialize.c
index adf1f76f7..2d1f61e4c 100644
--- a/nuttx/fs/nxffs/nxffs_initialize.c
+++ b/nuttx/fs/nxffs/nxffs_initialize.c
@@ -207,6 +207,19 @@ int nxffs_initialize(FAR struct mtd_dev_s *mtd)
       goto errout_with_volume;
     }
 
+  /* Pre-allocate one additional I/O block buffer to support filesystem
+   * packing.  This buffer is not needed often, but is best to have pre-
+   * allocated and in-place.
+   */
+
+  volume->pack = (FAR uint8_t *)kmalloc(volume->geo.blocksize);
+  if (!volume->pack)
+    {
+      fdbg("Failed to allocate an I/O block buffer\n");
+      ret = -ENOMEM;
+      goto errout_with_cache;
+    }
+
   /* Get the number of R/W blocks per erase block and the total number o
    * R/W blocks
    */
@@ -221,7 +234,7 @@ int nxffs_initialize(FAR struct mtd_dev_s *mtd)
   if (ret < 0)
     {
       fdbg("Failed to collect block statistics: %d\n", -ret);
-      goto errout_with_iobuffer;
+      goto errout_with_buffer;
     }
 
   /* If the proportion of good blocks is low or the proportion of unformatted
@@ -237,7 +250,7 @@ int nxffs_initialize(FAR struct mtd_dev_s *mtd)
       if (ret < 0)
         {
           fdbg("Failed to reformat the volume: %d\n", -ret);
-          goto errout_with_iobuffer;
+          goto errout_with_buffer;
         }
 
       /* Get statistics on the re-formatted volume */
@@ -247,7 +260,7 @@ int nxffs_initialize(FAR struct mtd_dev_s *mtd)
       if (ret < 0)
         {
           fdbg("Failed to collect block statistics: %d\n", -ret);
-          goto errout_with_iobuffer;
+          goto errout_with_buffer;
         }
 #endif
     }
@@ -261,7 +274,9 @@ int nxffs_initialize(FAR struct mtd_dev_s *mtd)
     }
   fdbg("Failed to calculate file system limits: %d\n", -ret);
 
-errout_with_iobuffer:
+errout_with_buffer:
+  kfree(volume->pack);
+errout_with_cache:
   kfree(volume->cache);
 errout_with_volume:
   kfree(volume);
diff --git a/nuttx/fs/nxffs/nxffs_pack.c b/nuttx/fs/nxffs/nxffs_pack.c
index 476c5972b..b44a15736 100644
--- a/nuttx/fs/nxffs/nxffs_pack.c
+++ b/nuttx/fs/nxffs/nxffs_pack.c
@@ -41,7 +41,10 @@
 
 #include <nuttx/config.h>
 
+#include <string.h>
 #include <errno.h>
+#include <assert.h>
+#include <debug.h>
 
 #include "nxffs.h"
 
@@ -52,6 +55,24 @@
 /****************************************************************************
  * Public Types
  ****************************************************************************/
+/* This structure supports access to one inode data stream */
+
+struct nxffs_packstream_s
+{
+  struct nxffs_entry_s entry;      /* Described the inode header */
+  off_t                fpos;       /* Current file position */
+  off_t                blkoffset;  /* Offset to the current data block */
+  uint16_t             blklen;     /* Size of this block */
+  uint16_t             blkpos;     /* Position in block corresponding to fpos */
+};
+
+/* The structure supports the overall packing operation */
+
+struct nxffs_pack_s
+{
+  struct nxffs_packstream_s src;   /* Describes the src stream */
+  struct nxffs_packstream_s dest;  /* Describes the destination stream */
+};
 
 /****************************************************************************
  * Public Variables
@@ -62,6 +83,140 @@
  ****************************************************************************/
 
 /****************************************************************************
+ * Name: nxffs_startblock
+ *
+ * Description:
+ *   Find the position in FLASH memory where we should begin packing.  That
+ *   position is the place where there is a gap between the last and the next
+ *   valid inode.
+ *
+ * Input Parameters:
+ *   volume - The volume to be packed.
+ *
+ * Returned Values:
+ *   Zero on success; Otherwise, a negated errno value is returned to
+ *   indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+static int nxffs_startblock(FAR struct nxffs_volume_s *volume,
+                            FAR struct nxffs_pack_s *pack)
+{
+  struct nxffs_blkentry_s blkentry;
+  off_t wasted;
+  off_t offset;
+  off_t nbytes;
+  int ret;
+
+  memset(pack, 0, sizeof(struct nxffs_pack_s));
+
+  /* Find the FLASH offset to the first valid block */
+
+  volume->ioblock = 0;
+  ret = nxffs_validblock(volume, &volume->ioblock);
+  if (ret < 0)
+   {
+     /* No valid blocks? */
+
+     return nxffs_reformat(volume);
+   }
+
+  volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
+  offset = nxffs_iotell(volume);
+
+  /* Loop until we find a gap of unused FLASH large enough to warrant the
+   * compression.
+   */
+
+  for(;;)
+    {
+      /* Get the offset to the first valid inode entry */
+
+      ret = nxffs_nextentry(volume, offset, &pack->src.entry);
+      if (ret < 0)
+        {
+          /* No valid entries -- reformat the flash */
+
+          return nxffs_reformat(volume);
+        }
+
+      /* Is there wasted space between the offset where the we could have
+       * valid data and the offset to the beginning of the first valid
+       * inode header?  NOTE:  The threshold check is not accurate, there
+       * may or may not be intervening block headers making the separation
+       * seem larger than it is.
+       */
+
+      DEBUGASSERT(pack->src.entry.hoffset >= offset);
+      wasted = pack->src.entry.hoffset - offset;
+      if (wasted > CONFIG_NXFFS_PACKTHRESHOLD)
+        {
+          /* This is where we must begin packing */
+
+          memcpy(&pack->dest.entry, &pack->src.entry, sizeof(struct nxffs_entry_s));
+          
+          pack->dest.entry.hoffset = offset;
+          pack->src.entry.name     = NULL;
+          return OK;
+        }
+
+      /* Free the allocated memory in the entry */
+
+      nxffs_freeentry(&pack->src.entry);
+
+      /* Update the offset to the first byte at the end of the last data
+       * block.
+       */
+
+      nbytes = 0;
+      offset = pack->src.entry.doffset;
+
+      while (nbytes < pack->src.entry.datlen)
+        {
+          /* Read the next data block header */
+
+          ret = nxffs_nextblock(volume, offset, &blkentry);
+          if (ret < 0)
+            {
+              fdbg("Failed to find next data block: %d\n", -ret);
+              return ret;
+            }
+
+          /* Get the number of blocks and pointer to where the next
+           * data block might lie.
+           */
+
+          nbytes += blkentry.datlen;
+          offset  = blkentry.hoffset + SIZEOF_NXFFS_DATA_HDR + blkentry.datlen;
+        }
+
+      /* Make sure there is space at this location for an inode header */
+
+      nxffs_ioseek(volume, offset);
+      if (volume->iooffset + SIZEOF_NXFFS_INODE_HDR > volume->geo.blocksize)
+        {
+          /* Find the next valid block */
+
+          volume->ioblock++;
+          ret = nxffs_validblock(volume, &volume->ioblock);
+          if (ret < 0)
+            {
+               /* No valid blocks? Then there is nothing we can do */
+
+               return -ENOSPC;
+            }
+
+          volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
+          offset = nxffs_iotell(volume);
+        }
+    }
+
+  /* We won't get here */
+
+  return -ENOSYS;
+}
+
+/****************************************************************************
  * Public Functions
  ****************************************************************************/
 
@@ -83,6 +238,29 @@
 
 int nxffs_pack(FAR struct nxffs_volume_s *volume)
 {
+  struct nxffs_pack_s pack;
+  int ret;
+
+  /* Get the offset to the first valid inode entry */
+
+  ret = nxffs_startblock(volume, &pack);
+  if (ret < 0)
+    {
+      fdbg("Failed to find a start block: %d\n", -ret);
+      return ret;
+    }
+
+  /* A special case is where the entire FLASH needs to be reformatted.  In
+   * this case, the source and destination offsets will both be zero.
+   */
+
+  if (pack.src.entry.hoffset == 0 && pack.dest.entry.hoffset == 0)
+    {
+      return OK;
+    }
+
+  /* Otherwise, begin pack at this src/dest block combination */
+
 # warning "Missing logic"
   return -ENOSYS;
 }
diff --git a/nuttx/fs/nxffs/nxffs_read.c b/nuttx/fs/nxffs/nxffs_read.c
index bb400e232..30fcd09aa 100644
--- a/nuttx/fs/nxffs/nxffs_read.c
+++ b/nuttx/fs/nxffs/nxffs_read.c
@@ -61,13 +61,6 @@
  * Public Types
  ****************************************************************************/
 
-struct nxffs_blkentry_s
-{
-  off_t     hoffset;  /* Offset to the block data header */
-  uint16_t  datlen;   /* Length of data following the header */
-  uint16_t  foffset;  /* Offset to start of data */
-};
-
 /****************************************************************************
  * Public Variables
  ****************************************************************************/
@@ -146,127 +139,6 @@ static int nxffs_rdblkhdr(FAR struct nxffs_volume_s *volume, off_t offset,
 }
 
 /****************************************************************************
- * Name: nxffs_nextblock
- *
- * Description:
- *   Search for the next valid data block starting at the provided
- *   FLASH offset.
- *
- * Input Parameters:
- *   volume - Describes the NXFFS volume.
- *   datlen  - A memory location to return the data block length.
- *  
- * Returned Value:
- *   Zero is returned on success. Otherwise, a negated errno is returned
- *   that indicates the nature of the failure.
- *
- ****************************************************************************/
-
-int nxffs_nextblock(FAR struct nxffs_volume_s *volume, off_t offset,
-                    FAR struct nxffs_blkentry_s *blkentry)
-{
-  int nmagic;
-  int ch;
-  int nerased;
-  int ret;
-
-  /* Seek to the first FLASH offset provided by the caller. */
-
-  nxffs_ioseek(volume, offset);
-
-  /* Skip the block header */
-
-  if (volume->iooffset < SIZEOF_NXFFS_BLOCK_HDR)
-    {
-      volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
-    }
-
-  /* Then begin searching */
-  
-  nerased = 0;
-  nmagic  = 0;
-
-  for (;;)
-    {
-      /* Read the next character */
-
-      ch = nxffs_getc(volume);
-      if (ch < 0)
-        {
-          fvdbg("nxffs_getc failed: %d\n", -ch);
-          return ch;
-        }
-
-      /* Check for another erased byte */
-
-      else if (ch == CONFIG_NXFFS_ERASEDSTATE)
-        {
-          /* If we have encountered NXFFS_NERASED number of consecutive
-           * erased bytes, then presume we have reached the end of valid
-           * data.
-           */
-
-          if (++nerased >= NXFFS_NERASED)
-            {
-              fvdbg("No entry found\n");
-              return -ENOENT;
-            }
-        }
-      else
-        {
-          nerased = 0;
-
-          /* Check for the magic sequence indicating the start of an NXFFS
-           * data block or start of the next inode. There is the possibility
-           * of this magic sequnce occurring in FLASH data.  However, the
-           * data block CRC should distinguish between real NXFFS data blocks
-           * headers and such false alarms.
-           */
-
-          if (ch != g_datamagic[nmagic])
-            {
-              nmagic = 0;
-            }
-          else if (nmagic < NXFFS_MAGICSIZE - 1)
-            {
-              nmagic++;
-            }
-
-          /* We have found the magic sequence in the FLASH data that may
-           * indicate the beginning of an NXFFS data block.
-           */
-
-          else 
-            {
-              /* The offset to the header must be 4 bytes before the current
-               * FLASH seek location.
-               */
-
-              blkentry->hoffset = nxffs_iotell(volume) - 4;
-
-              /* Read the block header and verify the block at that address */
-
-              ret = nxffs_rdblkhdr(volume, blkentry->hoffset, &blkentry->datlen);
-              if (ret == OK)
-                {
-                  fvdbg("Found a valid data block, offset: %d datlen: %d\n",
-                        blkentry->hoffset, blkentry->datlen);
-                  return OK;
-                }
-
-              /* False alarm.. keep looking */
-
-              nmagic = 0;
-            }
-        }
-    }
-
-  /* We won't get here, but to keep some compilers happy: */
-
-  return -ENOENT;
-}
-
-/****************************************************************************
  * Name: nxffs_rdseek
  *
  * Description:
@@ -444,3 +316,125 @@ errout:
   return (ssize_t)ret;
 }
 
+/****************************************************************************
+ * Name: nxffs_nextblock
+ *
+ * Description:
+ *   Search for the next valid data block starting at the provided
+ *   FLASH offset.
+ *
+ * Input Parameters:
+ *   volume - Describes the NXFFS volume.
+ *   datlen  - A memory location to return the data block length.
+ *  
+ * Returned Value:
+ *   Zero is returned on success. Otherwise, a negated errno is returned
+ *   that indicates the nature of the failure.
+ *
+ ****************************************************************************/
+
+int nxffs_nextblock(FAR struct nxffs_volume_s *volume, off_t offset,
+                    FAR struct nxffs_blkentry_s *blkentry)
+{
+  int nmagic;
+  int ch;
+  int nerased;
+  int ret;
+
+  /* Seek to the first FLASH offset provided by the caller. */
+
+  nxffs_ioseek(volume, offset);
+
+  /* Skip the block header */
+
+  if (volume->iooffset < SIZEOF_NXFFS_BLOCK_HDR)
+    {
+      volume->iooffset = SIZEOF_NXFFS_BLOCK_HDR;
+    }
+
+  /* Then begin searching */
+  
+  nerased = 0;
+  nmagic  = 0;
+
+  for (;;)
+    {
+      /* Read the next character */
+
+      ch = nxffs_getc(volume);
+      if (ch < 0)
+        {
+          fvdbg("nxffs_getc failed: %d\n", -ch);
+          return ch;
+        }
+
+      /* Check for another erased byte */
+
+      else if (ch == CONFIG_NXFFS_ERASEDSTATE)
+        {
+          /* If we have encountered NXFFS_NERASED number of consecutive
+           * erased bytes, then presume we have reached the end of valid
+           * data.
+           */
+
+          if (++nerased >= NXFFS_NERASED)
+            {
+              fvdbg("No entry found\n");
+              return -ENOENT;
+            }
+        }
+      else
+        {
+          nerased = 0;
+
+          /* Check for the magic sequence indicating the start of an NXFFS
+           * data block or start of the next inode. There is the possibility
+           * of this magic sequnce occurring in FLASH data.  However, the
+           * data block CRC should distinguish between real NXFFS data blocks
+           * headers and such false alarms.
+           */
+
+          if (ch != g_datamagic[nmagic])
+            {
+              nmagic = 0;
+            }
+          else if (nmagic < NXFFS_MAGICSIZE - 1)
+            {
+              nmagic++;
+            }
+
+          /* We have found the magic sequence in the FLASH data that may
+           * indicate the beginning of an NXFFS data block.
+           */
+
+          else 
+            {
+              /* The offset to the header must be 4 bytes before the current
+               * FLASH seek location.
+               */
+
+              blkentry->hoffset = nxffs_iotell(volume) - 4;
+
+              /* Read the block header and verify the block at that address */
+
+              ret = nxffs_rdblkhdr(volume, blkentry->hoffset, &blkentry->datlen);
+              if (ret == OK)
+                {
+                  fvdbg("Found a valid data block, offset: %d datlen: %d\n",
+                        blkentry->hoffset, blkentry->datlen);
+                  return OK;
+                }
+
+              /* False alarm.. keep looking */
+
+              nmagic = 0;
+            }
+        }
+    }
+
+  /* We won't get here, but to keep some compilers happy: */
+
+  return -ENOENT;
+}
+
+