NTFS: 2.0.9 release. Decompression engine now uses a single buffer and other cleanups.

- Remove unused variables left over after Rusty's patch to the decompression
  engine.
- Change buffer size in ntfs_readdir()/ntfs_filldir() to use
  NLS_MAX_CHARSET_SIZE.
- Miscellaneous minor cleanups to comments.

Documentation/filesystems/ntfs.txt

@@ -247,6 +247,12 @@ ChangeLog
 
 Note, a technical ChangeLog aimed at kernel hackers is in fs/ntfs/ChangeLog.
 
+2.0.9:
+	- Change decompression engine to use a single buffer. This should not
+	  affect performance except perhaps on the most heavy i/o on SMP
+	  systems when accessing multiple compressed files from multiple
+	  devices simultaneously.
+	- Minor updates and cleanups.
 2.0.8:
 	- Remove now obsolete show_inodes and posix mount option(s).
 	- Restore show_sys_files mount option.

fs/ntfs/ChangeLog

@@ -23,6 +23,17 @@ ToDo:
 	  them cleaner and make code reuse easier.
 	- Want to use dummy inodes for address space i/o.
 
+2.0.9 - Decompression engine now uses a single buffer and other cleanups.
+
+	- Change decompression engine to use a single buffer protected by a
+	  spin lock instead of per-CPU buffers. (Rusty Russel)
+	- Switch to using the new KM_BIO_SRC_IRQ for atomic kmaps. (Andrew
+	  Morton)
+	- Change buffer size in ntfs_readdir()/ntfs_filldir() to use
+	  NLS_MAX_CHARSET_SIZE which makes the buffers almost 1kiB each but
+	  it also makes everything safer so it is a good thing.
+	- Miscellaneous minor cleanups to comments.
+
 2.0.8 - Major updates for handling of case sensitivity and dcache aliasing.
 
 	Big thanks go to Al Viro and other inhabitants of #kernel for investing

fs/ntfs/Makefile

@@ -5,7 +5,7 @@ obj-$(CONFIG_NTFS_FS) += ntfs.o
 ntfs-objs := aops.o attrib.o compress.o debug.o dir.o file.o inode.o mft.o \
 	     mst.o namei.o super.o sysctl.o time.o unistr.o upcase.o
 
-EXTRA_CFLAGS = -DNTFS_VERSION=\"2.0.8\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.0.9\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG

fs/ntfs/compress.c

@@ -50,11 +50,13 @@ typedef enum {
 } ntfs_compression_constants;
 
 /**
- * ntfs_compression_buffer - one buffer for the decompression engine.
+ * ntfs_compression_buffer - one buffer for the decompression engine
  */
 static u8 *ntfs_compression_buffer = NULL;
 
-/* This spinlock which protects it */
+/**
+ * ntfs_cb_lock - spinlock which protects ntfs_compression_buffer
+ */
 static spinlock_t ntfs_cb_lock = SPIN_LOCK_UNLOCKED;
 
 /**
@@ -66,8 +68,6 @@ static spinlock_t ntfs_cb_lock = SPIN_LOCK_UNLOCKED;
  */
 int allocate_compression_buffers(void)
 {
-	int i, j;
-
 	BUG_ON(ntfs_compression_buffer);
 
 	ntfs_compression_buffer = vmalloc(NTFS_MAX_CB_SIZE);
@@ -83,8 +83,6 @@ int allocate_compression_buffers(void)
  */
 void free_compression_buffers(void)
 {
-	int i;
-
 	BUG_ON(!ntfs_compression_buffer);
 	vfree(ntfs_compression_buffer);
 	ntfs_compression_buffer = NULL;
@@ -592,7 +590,8 @@ int ntfs_file_read_compressed_block(struct page *page)
 
 	/*
 	 * Get the compression buffer. We must not sleep any more
-	 * until we are finished with it.  */
+	 * until we are finished with it.
+	 */
 	spin_lock(&ntfs_cb_lock);
 	cb = ntfs_compression_buffer;
 
@@ -668,7 +667,10 @@ int ntfs_file_read_compressed_block(struct page *page)
 			if (page)
 				memset(page_address(page) + cur_ofs, 0,
 						cb_max_ofs - cur_ofs);
-			cb_pos += cb_max_ofs - cur_ofs;
+			/*
+			 * No need to update cb_pos at this stage:
+			 *	cb_pos += cb_max_ofs - cur_ofs;
+			 */
 			cur_ofs = cb_max_ofs;
 		}
 	} else if (vcn == start_vcn) {
@@ -742,7 +744,8 @@ int ntfs_file_read_compressed_block(struct page *page)
 				cb_pos,	cb_size - (cb_pos - cb));
 		/*
 		 * We can sleep from now on, lock already dropped by
-		 * ntfs_decompress.  */
+		 * ntfs_decompress().
+		 */
 		if (err) {
 			ntfs_error(vol->sb, "ntfs_decompress() failed in inode "
 					"0x%Lx with error code %i. Skipping "

fs/ntfs/dir.c

@@ -995,10 +995,10 @@ typedef enum {
  * @ie:		current index entry
  * @name:	buffer to use for the converted name
  * @dirent:	vfs filldir callback context
- * filldir:	vfs filldir callback
+ * @filldir:	vfs filldir callback
  *
- * Convert the Unicode name to the loaded NLS and pass it to
- * the filldir callback.
+ * Convert the Unicode @name to the loaded NLS and pass it to the @filldir
+ * callback.
  */
 static inline int ntfs_filldir(ntfs_volume *vol, struct file *filp,
 		ntfs_inode *ndir, const INDEX_TYPE index_type,
@@ -1033,7 +1033,7 @@ static inline int ntfs_filldir(ntfs_volume *vol, struct file *filp,
 	}
 	name_len = ntfs_ucstonls(vol, (uchar_t*)&ie->key.file_name.file_name,
 			ie->key.file_name.file_name_length, &name,
-			NTFS_MAX_NAME_LEN * 3 + 1);
+			NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1);
 	if (name_len <= 0) {
 		ntfs_debug("Skipping unrepresentable file.");
 		return 0;
@@ -1126,7 +1126,8 @@ static int ntfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 	 * Allocate a buffer to store the current name being processed
 	 * converted to format determined by current NLS.
 	 */
-	name = (u8*)kmalloc(NTFS_MAX_NAME_LEN * 3 + 1, GFP_NOFS);
+	name = (u8*)kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1,
+			GFP_NOFS);
 	if (!name) {
 		err = -ENOMEM;
 		goto put_unm_err_out;

fs/ntfs/layout.h

@@ -948,8 +948,7 @@ typedef struct {
 					   data attribute. NOTE: Is a multiple
 					   of the cluster size. */
 /* 30*/	s64 data_size;			/* Byte size of actual data in data
-					   attribute. NOTE: Only present when
-					   lowest_vcn is 0. */
+					   attribute. */
 /* 38*/	FILE_ATTR_FLAGS file_attributes;	/* Flags describing the file. */
 /* 3c*/	union {
 	/* 3c*/	struct {

fs/ntfs/namei.c

@@ -235,8 +235,9 @@ static struct dentry *ntfs_lookup(struct inode *dir_ino, struct dentry *dent)
 	}
 	nls_name.hash = full_name_hash(nls_name.name, nls_name.len);
 
-	// FIXME: Do we need dcache_lock or dparent_lock here or is the
-	// fact that i_sem is held on the parent inode sufficient? (AIA)
+	/*
+	 * Note: No need for dparent_lock as i_sem is held on the parent inode.
+	 */
 
 	/* Does a dentry matching the nls_name exist already? */
 	real_dent = d_lookup(dent->d_parent, &nls_name);