NTFS: 2.0.24 - Cleanups.

- Treat BUG_ON() as ASSERT() not VERIFY(), i.e. do not use side effects
  inside BUG_ON(). (Adam J. Richter)
- Split logical OR expressions inside BUG_ON() into individual BUG_ON()
  calls for improved debugging. (Adam J. Richter)
- Add errors flag to the ntfs volume state, accessed via
  NVol{,Set,Clear}Errors(vol).
- Do not allow read-write remounts of read-only volumes with errors.
- Clarify comment for ntfs file operation sendfile which was added by
  Christoph Hellwig a while ago (just using generic_file_sendfile())
  to say that ntfs ->sendfile is only used for the case where the
  source data is on the ntfs partition and the destination is
  somewhere else, i.e. nothing we need to concern ourselves with.

Documentation/filesystems/ntfs.txt

@@ -247,6 +247,9 @@ ChangeLog
 
 Note, a technical ChangeLog aimed at kernel hackers is in fs/ntfs/ChangeLog.
 
+2.0.24:
+	- Small internal cleanups.
+	- Support for sendfile system call. (Christoph Hellwig)
 2.0.23:
 	- Massive internal locking changes to mft record locking. Fixes
 	  various race conditions and deadlocks.

fs/ntfs/ChangeLog

@@ -2,6 +2,22 @@ ToDo:
 	- Find and fix bugs.
 	- Enable NFS exporting of NTFS.
 
+2.0.24 - Cleanups.
+
+	- Treat BUG_ON() as ASSERT() not VERIFY(), i.e. do not use side effects
+	  inside BUG_ON(). (Adam J. Richter)
+	- Split logical OR expressions inside BUG_ON() into individual BUG_ON()
+	  calls for improved debugging. (Adam J. Richter)
+	- Add errors flag to the ntfs volume state, accessed via
+	  NVol{,Set,Clear}Errors(vol).
+	- Do not allow read-write remounts of read-only volumes with errors.
+	- Clarify comment for ntfs file operation sendfile which was added by
+	  Christoph Hellwig a while ago (just using generic_file_sendfile())
+	  to say that ntfs ->sendfile is only used for the case where the
+	  source data is on the ntfs partition and the destination is
+	  somewhere else, i.e. nothing we need to concern ourselves with.
+	- Add generic_file_write() as our ntfs file write operation.
+
 2.0.23 - Major bug fixes (races, deadlocks, non-i386 architectures).
 
 	- Massive internal locking changes to mft record locking. Fixes lock

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=\"2.0.23\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.0.24\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG

fs/ntfs/attrib.c

@@ -110,7 +110,8 @@ static inline run_list_element *ntfs_rl_realloc(run_list_element *rl,
 static inline BOOL ntfs_are_rl_mergeable(run_list_element *dst,
 		run_list_element *src)
 {
-	BUG_ON(!dst || !src);
+	BUG_ON(!dst);
+	BUG_ON(!src);
 
 	if ((dst->lcn < 0) || (src->lcn < 0))     /* Are we merging holes? */
 		return FALSE;
@@ -192,7 +193,8 @@ static inline run_list_element *ntfs_rl_append(run_list_element *dst,
 	BOOL right;
 	int magic;
 
-	BUG_ON(!dst || !src);
+	BUG_ON(!dst);
+	BUG_ON(!src);
 
 	/* First, check if the right hand end needs merging. */
 	right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
@@ -258,7 +260,8 @@ static inline run_list_element *ntfs_rl_insert(run_list_element *dst,
 	BOOL hole = FALSE;	/* Following a hole */
 	int magic;
 
-	BUG_ON(!dst || !src);
+	BUG_ON(!dst);
+	BUG_ON(!src);
 
 	/* disc => Discontinuity between the end of @dst and the start of @src.
 	 *         This means we might need to insert a hole.
@@ -362,7 +365,8 @@ static inline run_list_element *ntfs_rl_replace(run_list_element *dst,
 	BOOL right;
 	int magic;
 
-	BUG_ON(!dst || !src);
+	BUG_ON(!dst);
+	BUG_ON(!src);
 
 	/* First, merge the left and right ends, if necessary. */
 	right = ntfs_are_rl_mergeable(src + ssize - 1, dst + loc + 1);
@@ -423,7 +427,8 @@ static inline run_list_element *ntfs_rl_replace(run_list_element *dst,
 static inline run_list_element *ntfs_rl_split(run_list_element *dst, int dsize,
 		run_list_element *src, int ssize, int loc)
 {
-	BUG_ON(!dst || !src);
+	BUG_ON(!dst);
+	BUG_ON(!src);
 
 	/* Space required: @dst size + @src size + one new hole. */
 	dst = ntfs_rl_realloc(dst, dsize, dsize + ssize + 1);

fs/ntfs/compress.c

@@ -467,7 +467,8 @@ int ntfs_read_compressed_block(struct page *page)
 	 * Bad things happen if we get here for anything that is not an
 	 * unnamed $DATA attribute.
 	 */
-	BUG_ON(ni->type != AT_DATA || ni->name_len);
+	BUG_ON(ni->type != AT_DATA);
+	BUG_ON(ni->name_len);
 
 	pages = kmalloc(nr_pages * sizeof(struct page *), GFP_NOFS);
 

fs/ntfs/file.c

@@ -51,8 +51,15 @@ static int ntfs_file_open(struct inode *vi, struct file *filp)
 struct file_operations ntfs_file_ops = {
 	.llseek		= generic_file_llseek,	/* Seek inside file. */
 	.read		= generic_file_read,	/* Read from file. */
+#ifdef NTFS_RW
+	.write		= generic_file_write,	/* Write to a file. */
+#endif
 	.mmap		= generic_file_mmap,	/* Mmap file. */
- 	.sendfile	= generic_file_sendfile,/* Zero-copy data send. */
+	.sendfile	= generic_file_sendfile,/* Zero-copy data send with the
+						   data source being on the
+						   ntfs partition. We don't
+						   need to care about the data
+						   destination. */
 	.open		= ntfs_file_open,	/* Open file. */
 };
 

fs/ntfs/inode.c

@@ -278,7 +278,9 @@ void ntfs_destroy_big_inode(struct inode *inode)
 	ntfs_inode *ni = NTFS_I(inode);
 
 	ntfs_debug("Entering.");
-	BUG_ON(ni->page || !atomic_dec_and_test(&ni->count));
+	BUG_ON(ni->page);
+	if (!atomic_dec_and_test(&ni->count))
+		BUG();
 	kmem_cache_free(ntfs_big_inode_cache, NTFS_I(inode));
 }
 
@@ -299,7 +301,9 @@ static inline ntfs_inode *ntfs_alloc_extent_inode(void)
 void ntfs_destroy_extent_inode(ntfs_inode *ni)
 {
 	ntfs_debug("Entering.");
-	BUG_ON(ni->page || !atomic_dec_and_test(&ni->count));
+	BUG_ON(ni->page);
+	if (!atomic_dec_and_test(&ni->count))
+		BUG();
 	kmem_cache_free(ntfs_inode_cache, ni);
 }
 

fs/ntfs/super.c

@@ -307,6 +307,23 @@ static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
 
 	ntfs_debug("Entering with remount options string: %s", opt);
 
+#ifndef NTFS_RW
+	/* For read-only compiled driver, enforce all read-only flags. */
+	*flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
+#else
+	/*
+	 * For the read-write compiled driver, if we are remounting read-write,
+	 * make sure there aren't any volume errors.
+	 */
+	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
+		if (NVolErrors(vol)) {
+			ntfs_error(sb, "Volume has errors and is read-only."
+					"Cannot remount read-write.");
+			return -EROFS;
+		}
+	}
+#endif
+
 	// FIXME/TODO: If left like this we will have problems with rw->ro and
 	// ro->rw, as well as with sync->async and vice versa remounts.
 	// Note: The VFS already checks that there are no pending deletes and
@@ -324,10 +341,6 @@ static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
 	if (!parse_options(vol, opt))
 		return -EINVAL;
 
-#ifndef NTFS_RW
-	*flags |= MS_RDONLY | MS_NOATIME | MS_NODIRATIME;
-#endif
-
 	return 0;
 }
 

fs/ntfs/volume.h

@@ -101,6 +101,7 @@ typedef struct {
  * Defined bits for the flags field in the ntfs_volume structure.
  */
 typedef enum {
+	NV_Errors,		/* 1: Volume has errors, prevent remount rw. */
 	NV_ShowSystemFiles,	/* 1: Return system files in ntfs_readdir(). */
 	NV_CaseSensitive,	/* 1: Treat file names as case sensitive and
 				      create filenames in the POSIX namespace.
@@ -127,6 +128,7 @@ static inline void NVolClear##flag(ntfs_volume *vol)	\
 }
 
 /* Emit the ntfs volume bitops functions. */
+NVOL_FNS(Errors)
 NVOL_FNS(ShowSystemFiles)
 NVOL_FNS(CaseSensitive)