Merge git://git.kernel.org/pub/scm/linux/kernel/git/aia21/ntfs-2.6

Documentation/filesystems/ntfs.txt

@@ -50,9 +50,14 @@ userspace utilities, etc.
 Features
 ========
 
-- This is a complete rewrite of the NTFS driver that used to be in the kernel.
-  This new driver implements NTFS read support and is functionally equivalent
-  to the old ntfs driver.
+- This is a complete rewrite of the NTFS driver that used to be in the 2.4 and
+  earlier kernels.  This new driver implements NTFS read support and is
+  functionally equivalent to the old ntfs driver and it also implements limited
+  write support.  The biggest limitation at present is that files/directories
+  cannot be created or deleted.  See below for the list of write features that
+  are so far supported.  Another limitation is that writing to compressed files
+  is not implemented at all.  Also, neither read nor write access to encrypted
+  files is so far implemented.
 - The new driver has full support for sparse files on NTFS 3.x volumes which
   the old driver isn't happy with.
 - The new driver supports execution of binaries due to mmap() now being
@@ -78,7 +83,20 @@ Features
 - The new driver supports fsync(2), fdatasync(2), and msync(2).
 - The new driver supports readv(2) and writev(2).
 - The new driver supports access time updates (including mtime and ctime).
-
+- The new driver supports truncate(2) and open(2) with O_TRUNC.  But at present
+  only very limited support for highly fragmented files, i.e. ones which have
+  their data attribute split across multiple extents, is included.  Another
+  limitation is that at present truncate(2) will never create sparse files,
+  since to mark a file sparse we need to modify the directory entry for the
+  file and we do not implement directory modifications yet.
+- The new driver supports write(2) which can both overwrite existing data and
+  extend the file size so that you can write beyond the existing data.  Also,
+  writing into sparse regions is supported and the holes are filled in with
+  clusters.  But at present only limited support for highly fragmented files,
+  i.e. ones which have their data attribute split across multiple extents, is
+  included.  Another limitation is that write(2) will never create sparse
+  files, since to mark a file sparse we need to modify the directory entry for
+  the file and we do not implement directory modifications yet.
 
 Supported mount options
 =======================
@@ -439,6 +457,22 @@ ChangeLog
 
 Note, a technical ChangeLog aimed at kernel hackers is in fs/ntfs/ChangeLog.
 
+2.1.25:
+	- Write support is now extended with write(2) being able to both
+	  overwrite existing file data and to extend files.  Also, if a write
+	  to a sparse region occurs, write(2) will fill in the hole.  Note,
+	  mmap(2) based writes still do not support writing into holes or
+	  writing beyond the initialized size.
+	- Write support has a new feature and that is that truncate(2) and
+	  open(2) with O_TRUNC are now implemented thus files can be both made
+	  smaller and larger.
+	- Note: Both write(2) and truncate(2)/open(2) with O_TRUNC still have
+	  limitations in that they
+	  - only provide limited support for highly fragmented files.
+	  - only work on regular, i.e. uncompressed and unencrypted files.
+	  - never create sparse files although this will change once directory
+	    operations are implemented.
+	- Lots of bug fixes and enhancements across the board.
 2.1.24:
 	- Support journals ($LogFile) which have been modified by chkdsk.  This
 	  means users can boot into Windows after we marked the volume dirty.

fs/ntfs/ChangeLog

 ToDo/Notes:
 	- Find and fix bugs.
-	- In between ntfs_prepare/commit_write, need exclusion between
-	  simultaneous file extensions.  This is given to us by holding i_sem
-	  on the inode.  The only places in the kernel when a file is resized
-	  are prepare/commit write and truncate for both of which i_sem is
-	  held.  Just have to be careful in readpage/writepage and all other
-	  helpers not running under i_sem that we play nice...
-	  Also need to be careful with initialized_size extention in
-	  ntfs_prepare_write. Basically, just be _very_ careful in this code...
-	  UPDATE: The only things that need to be checked are read/writepage
-	  which do not hold i_sem.  Note writepage cannot change i_size but it
-	  needs to cope with a concurrent i_size change, just like readpage.
-	  Also both need to cope with concurrent changes to the other sizes,
-	  i.e. initialized/allocated/compressed size, as well.
+	- The only places in the kernel where a file is resized are
+	  ntfs_file_write*() and ntfs_truncate() for both of which i_sem is
+	  held.  Just have to be careful in read-/writepage and other helpers
+	  not running under i_sem that we play nice...  Also need to be careful
+	  with initialized_size extension in ntfs_file_write*() and writepage.
+	  UPDATE: The only things that need to be checked are the compressed
+	  write and the other attribute resize/write cases like index
+	  attributes, etc.  For now none of these are implemented so are safe.
+	- Implement filling in of holes in aops.c::ntfs_writepage() and its
+	  helpers.
 	- Implement mft.c::sync_mft_mirror_umount().  We currently will just
 	  leave the volume dirty on umount if the final iput(vol->mft_ino)
 	  causes a write of any mirrored mft records due to the mft mirror
@@ -22,6 +19,68 @@ ToDo/Notes:
 	- Enable the code for setting the NT4 compatibility flag when we start
 	  making NTFS 1.2 specific modifications.
 
+2.1.25 - (Almost) fully implement write(2) and truncate(2).
+
+	- Change ntfs_map_runlist_nolock(), ntfs_attr_find_vcn_nolock() and
+	  {__,}ntfs_cluster_free() to also take an optional attribute search
+	  context as argument.  This allows calling these functions with the
+	  mft record mapped.  Update all callers.
+	- Fix potential deadlock in ntfs_mft_data_extend_allocation_nolock()
+	  error handling by passing in the active search context when calling
+	  ntfs_cluster_free().
+	- Change ntfs_cluster_alloc() to take an extra boolean parameter
+	  specifying whether the cluster are being allocated to extend an
+	  attribute or to fill a hole.
+	- Change ntfs_attr_make_non_resident() to call ntfs_cluster_alloc()
+	  with @is_extension set to TRUE and remove the runlist terminator
+	  fixup code as this is now done by ntfs_cluster_alloc().
+	- Change ntfs_attr_make_non_resident to take the attribute value size
+	  as an extra parameter.  This is needed since we need to know the size
+	  before we can map the mft record and our callers always know it.  The
+	  reason we cannot simply read the size from the vfs inode i_size is
+	  that this is not necessarily uptodate.  This happens when
+	  ntfs_attr_make_non_resident() is called in the ->truncate call path.
+	- Fix ntfs_attr_make_non_resident() to update the vfs inode i_blocks
+	  which is zero for a resident attribute but should no longer be zero
+	  once the attribute is non-resident as it then has real clusters
+	  allocated.
+	- Add fs/ntfs/attrib.[hc]::ntfs_attr_extend_allocation(), a function to
+	  extend the allocation of an attributes.  Optionally, the data size,
+	  but not the initialized size can be extended, too.
+	- Implement fs/ntfs/inode.[hc]::ntfs_truncate().  It only supports
+	  uncompressed and unencrypted files and it never creates sparse files
+	  at least for the moment (making a file sparse requires us to modify
+	  its directory entries and we do not support directory operations at
+	  the moment).  Also, support for highly fragmented files, i.e. ones
+	  whose data attribute is split across multiple extents, is severly
+	  limited.  When such a case is encountered, EOPNOTSUPP is returned.
+	- Enable ATTR_SIZE attribute changes in ntfs_setattr().  This completes
+	  the initial implementation of file truncation.  Now both open(2)ing
+	  a file with the O_TRUNC flag and the {,f}truncate(2) system calls
+	  will resize a file appropriately.  The limitations are that only
+	  uncompressed and unencrypted files are supported.  Also, there is
+	  only very limited support for highly fragmented files (the ones whose
+	  $DATA attribute is split into multiple attribute extents).
+	- In attrib.c::ntfs_attr_set() call balance_dirty_pages_ratelimited()
+	  and cond_resched() in the main loop as we could be dirtying a lot of
+	  pages and this ensures we play nice with the VM and the system as a
+	  whole.
+	- Implement file operations ->write, ->aio_write, ->writev for regular
+	  files.  This replaces the old use of generic_file_write(), et al and
+	  the address space operations ->prepare_write and ->commit_write.
+	  This means that both sparse and non-sparse (unencrypted and
+	  uncompressed) files can now be extended using the normal write(2)
+	  code path.  There are two limitations at present and these are that
+	  we never create sparse files and that we only have limited support
+	  for highly fragmented files, i.e. ones whose data attribute is split
+	  across multiple extents.   When such a case is encountered,
+	  EOPNOTSUPP is returned.
+	- $EA attributes can be both resident and non-resident.
+	- Use %z for size_t to fix compilation warnings.  (Andrew Morton)
+	- Fix compilation warnings with gcc-4.0.2 on SUSE 10.0.
+	- Document extended attribute ($EA) NEED_EA flag.  (Based on libntfs
+	  patch by Yura Pakhuchiy.)
+
 2.1.24 - Lots of bug fixes and support more clean journal states.
 
 	- Support journals ($LogFile) which have been modified by chkdsk.  This

fs/ntfs/Makefile

@@ -6,7 +6,7 @@ ntfs-objs := aops.o attrib.o collate.o compress.o debug.o dir.o file.o \
 	     index.o inode.o mft.o mst.o namei.o runlist.o super.o sysctl.o \
 	     unistr.o upcase.o
 
-EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.24\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.25\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG

fs/ntfs/attrib.h

@@ -60,14 +60,15 @@ typedef struct {
 	ATTR_RECORD *base_attr;
 } ntfs_attr_search_ctx;
 
-extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn);
+extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn,
+		ntfs_attr_search_ctx *ctx);
 extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn);
 
 extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn,
 		const BOOL write_locked);
 
 extern runlist_element *ntfs_attr_find_vcn_nolock(ntfs_inode *ni,
-		const VCN vcn, const BOOL write_locked);
+		const VCN vcn, ntfs_attr_search_ctx *ctx);
 
 int ntfs_attr_lookup(const ATTR_TYPE type, const ntfschar *name,
 		const u32 name_len, const IGNORE_CASE_BOOL ic,
@@ -102,7 +103,10 @@ extern int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size);
 extern int ntfs_resident_attr_value_resize(MFT_RECORD *m, ATTR_RECORD *a,
 		const u32 new_size);
 
-extern int ntfs_attr_make_non_resident(ntfs_inode *ni);
+extern int ntfs_attr_make_non_resident(ntfs_inode *ni, const u32 data_size);
+
+extern s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
+		const s64 new_data_size, const s64 data_start);
 
 extern int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt,
 		const u8 val);

fs/ntfs/layout.h

@@ -1021,10 +1021,17 @@ enum {
 	FILE_NAME_POSIX		= 0x00,
 	/* This is the largest namespace. It is case sensitive and allows all
 	   Unicode characters except for: '\0' and '/'.  Beware that in
-	   WinNT/2k files which eg have the same name except for their case
-	   will not be distinguished by the standard utilities and thus a "del
-	   filename" will delete both "filename" and "fileName" without
-	   warning. */
+	   WinNT/2k/2003 by default files which eg have the same name except
+	   for their case will not be distinguished by the standard utilities
+	   and thus a "del filename" will delete both "filename" and "fileName"
+	   without warning.  However if for example Services For Unix (SFU) are
+	   installed and the case sensitive option was enabled at installation
+	   time, then you can create/access/delete such files.
+	   Note that even SFU places restrictions on the filenames beyond the
+	   '\0' and '/' and in particular the following set of characters is
+	   not allowed: '"', '/', '<', '>', '\'.  All other characters,
+	   including the ones no allowed in WIN32 namespace are allowed.
+	   Tested with SFU 3.5 (this is now free) running on Windows XP. */
 	FILE_NAME_WIN32		= 0x01,
 	/* The standard WinNT/2k NTFS long filenames. Case insensitive.  All
 	   Unicode chars except: '\0', '"', '*', '/', ':', '<', '>', '?', '\',
@@ -2367,7 +2374,9 @@ typedef struct {
  * Extended attribute flags (8-bit).
  */
 enum {
-	NEED_EA	= 0x80
+	NEED_EA	= 0x80		/* If set the file to which the EA belongs
+				   cannot be interpreted without understanding
+				   the associates extended attributes. */
 } __attribute__ ((__packed__));
 
 typedef u8 EA_FLAGS;
@@ -2375,20 +2384,20 @@ typedef u8 EA_FLAGS;
 /*
  * Attribute: Extended attribute (EA) (0xe0).
  *
- * NOTE: Always non-resident. (Is this true?)
+ * NOTE: Can be resident or non-resident.
  *
  * Like the attribute list and the index buffer list, the EA attribute value is
  * a sequence of EA_ATTR variable length records.
- *
- * FIXME: It appears weird that the EA name is not unicode. Is it true?
  */
 typedef struct {
 	le32 next_entry_offset;	/* Offset to the next EA_ATTR. */
 	EA_FLAGS flags;		/* Flags describing the EA. */
-	u8 ea_name_length;	/* Length of the name of the EA in bytes. */
+	u8 ea_name_length;	/* Length of the name of the EA in bytes
+				   excluding the '\0' byte terminator. */
 	le16 ea_value_length;	/* Byte size of the EA's value. */
-	u8 ea_name[0];		/* Name of the EA. */
-	u8 ea_value[0];		/* The value of the EA. Immediately follows
+	u8 ea_name[0];		/* Name of the EA.  Note this is ASCII, not
+				   Unicode and it is zero terminated. */
+	u8 ea_value[0];		/* The value of the EA.  Immediately follows
 				   the name. */
 } __attribute__ ((__packed__)) EA_ATTR;
 

fs/ntfs/lcnalloc.c

@@ -76,6 +76,7 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  * @count:	number of clusters to allocate
  * @start_lcn:	starting lcn at which to allocate the clusters (or -1 if none)
  * @zone:	zone from which to allocate the clusters
+ * @is_extension:	if TRUE, this is an attribute extension
  *
  * Allocate @count clusters preferably starting at cluster @start_lcn or at the
  * current allocator position if @start_lcn is -1, on the mounted ntfs volume
@@ -86,6 +87,13 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  * @start_vcn specifies the vcn of the first allocated cluster.  This makes
  * merging the resulting runlist with the old runlist easier.
  *
+ * If @is_extension is TRUE, the caller is allocating clusters to extend an
+ * attribute and if it is FALSE, the caller is allocating clusters to fill a
+ * hole in an attribute.  Practically the difference is that if @is_extension
+ * is TRUE the returned runlist will be terminated with LCN_ENOENT and if
+ * @is_extension is FALSE the runlist will be terminated with
+ * LCN_RL_NOT_MAPPED.
+ *
  * You need to check the return value with IS_ERR().  If this is false, the
  * function was successful and the return value is a runlist describing the
  * allocated cluster(s).  If IS_ERR() is true, the function failed and
@@ -137,7 +145,8 @@ int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,
  */
 runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
 		const s64 count, const LCN start_lcn,
-		const NTFS_CLUSTER_ALLOCATION_ZONES zone)
+		const NTFS_CLUSTER_ALLOCATION_ZONES zone,
+		const BOOL is_extension)
 {
 	LCN zone_start, zone_end, bmp_pos, bmp_initial_pos, last_read_pos, lcn;
 	LCN prev_lcn = 0, prev_run_len = 0, mft_zone_size;
@@ -310,7 +319,7 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
 				continue;
 			}
 			bit = 1 << (lcn & 7);
-			ntfs_debug("bit %i.", bit);
+			ntfs_debug("bit 0x%x.", bit);
 			/* If the bit is already set, go onto the next one. */
 			if (*byte & bit) {
 				lcn++;
@@ -729,7 +738,7 @@ switch_to_data1_zone:		search_zone = 2;
 	/* Add runlist terminator element. */
 	if (likely(rl)) {
 		rl[rlpos].vcn = rl[rlpos - 1].vcn + rl[rlpos - 1].length;
-		rl[rlpos].lcn = LCN_RL_NOT_MAPPED;
+		rl[rlpos].lcn = is_extension ? LCN_ENOENT : LCN_RL_NOT_MAPPED;
 		rl[rlpos].length = 0;
 	}
 	if (likely(page && !IS_ERR(page))) {
@@ -782,6 +791,7 @@ switch_to_data1_zone:		search_zone = 2;
  * @ni:		ntfs inode whose runlist describes the clusters to free
  * @start_vcn:	vcn in the runlist of @ni at which to start freeing clusters
  * @count:	number of clusters to free or -1 for all clusters
+ * @ctx:	active attribute search context if present or NULL if not
  * @is_rollback:	true if this is a rollback operation
  *
  * Free @count clusters starting at the cluster @start_vcn in the runlist
@@ -791,15 +801,39 @@ switch_to_data1_zone:		search_zone = 2;
  * deallocated.  Thus, to completely free all clusters in a runlist, use
  * @start_vcn = 0 and @count = -1.
  *
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record.  This is needed when __ntfs_cluster_free() encounters unmapped
+ * runlist fragments and allows their mapping.  If you do not have the mft
+ * record mapped, you can specify @ctx as NULL and __ntfs_cluster_free() will
+ * perform the necessary mapping and unmapping.
+ *
+ * Note, __ntfs_cluster_free() saves the state of @ctx on entry and restores it
+ * before returning.  Thus, @ctx will be left pointing to the same attribute on
+ * return as on entry.  However, the actual pointers in @ctx may point to
+ * different memory locations on return, so you must remember to reset any
+ * cached pointers from the @ctx, i.e. after the call to __ntfs_cluster_free(),
+ * you will probably want to do:
+ *	m = ctx->mrec;
+ *	a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ *
  * @is_rollback should always be FALSE, it is for internal use to rollback
  * errors.  You probably want to use ntfs_cluster_free() instead.
  *
- * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
- * has to deal with it later.
+ * Note, __ntfs_cluster_free() does not modify the runlist, so you have to
+ * remove from the runlist or mark sparse the freed runs later.
  *
  * Return the number of deallocated clusters (not counting sparse ones) on
  * success and -errno on error.
  *
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ *	    returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx
+ *	    is no longer valid, i.e. you need to either call
+ *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ *	    why the mapping of the old inode failed.
+ *
  * Locking: - The runlist described by @ni must be locked for writing on entry
  *	      and is locked on return.  Note the runlist may be modified when
  *	      needed runlist fragments need to be mapped.
@@ -807,9 +841,13 @@ switch_to_data1_zone:		search_zone = 2;
  *	      on return.
  *	    - This function takes the volume lcn bitmap lock for writing and
  *	      modifies the bitmap contents.
+ *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ *	      entry and it will be left unmapped on return.
+ *	    - If @ctx is not NULL, the base mft record must be mapped on entry
+ *	      and it will be left mapped on return.
  */
 s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
-		const BOOL is_rollback)
+		ntfs_attr_search_ctx *ctx, const BOOL is_rollback)
 {
 	s64 delta, to_free, total_freed, real_freed;
 	ntfs_volume *vol;
@@ -839,7 +877,7 @@ s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
 
 	total_freed = real_freed = 0;
 
-	rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, TRUE);
+	rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, ctx);
 	if (IS_ERR(rl)) {
 		if (!is_rollback)
 			ntfs_error(vol->sb, "Failed to find first runlist "
@@ -893,7 +931,7 @@ s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
 
 			/* Attempt to map runlist. */
 			vcn = rl->vcn;
-			rl = ntfs_attr_find_vcn_nolock(ni, vcn, TRUE);
+			rl = ntfs_attr_find_vcn_nolock(ni, vcn, ctx);
 			if (IS_ERR(rl)) {
 				err = PTR_ERR(rl);
 				if (!is_rollback)
@@ -961,7 +999,7 @@ s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn, s64 count,
 	 * If rollback fails, set the volume errors flag, emit an error
 	 * message, and return the error code.
 	 */
-	delta = __ntfs_cluster_free(ni, start_vcn, total_freed, TRUE);
+	delta = __ntfs_cluster_free(ni, start_vcn, total_freed, ctx, TRUE);
 	if (delta < 0) {
 		ntfs_error(vol->sb, "Failed to rollback (error %i).  Leaving "
 				"inconsistent metadata!  Unmount and run "

fs/ntfs/lcnalloc.h

@@ -27,6 +27,7 @@
 
 #include <linux/fs.h>
 
+#include "attrib.h"
 #include "types.h"
 #include "inode.h"
 #include "runlist.h"
@@ -41,16 +42,18 @@ typedef enum {
 
 extern runlist_element *ntfs_cluster_alloc(ntfs_volume *vol,
 		const VCN start_vcn, const s64 count, const LCN start_lcn,
-		const NTFS_CLUSTER_ALLOCATION_ZONES zone);
+		const NTFS_CLUSTER_ALLOCATION_ZONES zone,
+		const BOOL is_extension);
 
 extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
-		s64 count, const BOOL is_rollback);
+		s64 count, ntfs_attr_search_ctx *ctx, const BOOL is_rollback);
 
 /**
  * ntfs_cluster_free - free clusters on an ntfs volume
  * @ni:		ntfs inode whose runlist describes the clusters to free
  * @start_vcn:	vcn in the runlist of @ni at which to start freeing clusters
  * @count:	number of clusters to free or -1 for all clusters
+ * @ctx:	active attribute search context if present or NULL if not
  *
  * Free @count clusters starting at the cluster @start_vcn in the runlist
  * described by the ntfs inode @ni.
@@ -59,12 +62,36 @@ extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
  * deallocated.  Thus, to completely free all clusters in a runlist, use
  * @start_vcn = 0 and @count = -1.
  *
- * Note, ntfs_cluster_free() does not modify the runlist at all, so the caller
- * has to deal with it later.
+ * If @ctx is specified, it is an active search context of @ni and its base mft
+ * record.  This is needed when ntfs_cluster_free() encounters unmapped runlist
+ * fragments and allows their mapping.  If you do not have the mft record
+ * mapped, you can specify @ctx as NULL and ntfs_cluster_free() will perform
+ * the necessary mapping and unmapping.
+ *
+ * Note, ntfs_cluster_free() saves the state of @ctx on entry and restores it
+ * before returning.  Thus, @ctx will be left pointing to the same attribute on
+ * return as on entry.  However, the actual pointers in @ctx may point to
+ * different memory locations on return, so you must remember to reset any
+ * cached pointers from the @ctx, i.e. after the call to ntfs_cluster_free(),
+ * you will probably want to do:
+ *	m = ctx->mrec;
+ *	a = ctx->attr;
+ * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that
+ * you cache ctx->mrec in a variable @m of type MFT_RECORD *.
+ *
+ * Note, ntfs_cluster_free() does not modify the runlist, so you have to remove
+ * from the runlist or mark sparse the freed runs later.
  *
  * Return the number of deallocated clusters (not counting sparse ones) on
  * success and -errno on error.
  *
+ * WARNING: If @ctx is supplied, regardless of whether success or failure is
+ *	    returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx
+ *	    is no longer valid, i.e. you need to either call
+ *	    ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it.
+ *	    In that case PTR_ERR(@ctx->mrec) will give you the error code for
+ *	    why the mapping of the old inode failed.
+ *
  * Locking: - The runlist described by @ni must be locked for writing on entry
  *	      and is locked on return.  Note the runlist may be modified when
  *	      needed runlist fragments need to be mapped.
@@ -72,11 +99,15 @@ extern s64 __ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
  *	      on return.
  *	    - This function takes the volume lcn bitmap lock for writing and
  *	      modifies the bitmap contents.
+ *	    - If @ctx is NULL, the base mft record of @ni must not be mapped on
+ *	      entry and it will be left unmapped on return.
+ *	    - If @ctx is not NULL, the base mft record must be mapped on entry
+ *	      and it will be left mapped on return.
  */
 static inline s64 ntfs_cluster_free(ntfs_inode *ni, const VCN start_vcn,
-		s64 count)
+		s64 count, ntfs_attr_search_ctx *ctx)
 {
-	return __ntfs_cluster_free(ni, start_vcn, count, FALSE);
+	return __ntfs_cluster_free(ni, start_vcn, count, ctx, FALSE);
 }
 
 extern int ntfs_cluster_free_from_rl_nolock(ntfs_volume *vol,

fs/ntfs/malloc.h

@@ -39,8 +39,7 @@
  * If there was insufficient memory to complete the request, return NULL.
  * Depending on @gfp_mask the allocation may be guaranteed to succeed.
  */
-static inline void *__ntfs_malloc(unsigned long size,
-		gfp_t gfp_mask)
+static inline void *__ntfs_malloc(unsigned long size, gfp_t gfp_mask)
 {
 	if (likely(size <= PAGE_SIZE)) {
 		BUG_ON(!size);

fs/ntfs/mft.c

@@ -49,7 +49,8 @@ static inline MFT_RECORD *map_mft_record_page(ntfs_inode *ni)
 	ntfs_volume *vol = ni->vol;
 	struct inode *mft_vi = vol->mft_ino;
 	struct page *page;
-	unsigned long index, ofs, end_index;
+	unsigned long index, end_index;
+	unsigned ofs;
 
 	BUG_ON(ni->page);
 	/*
@@ -1308,7 +1309,7 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
 	ll = mftbmp_ni->allocated_size;
 	read_unlock_irqrestore(&mftbmp_ni->size_lock, flags);
 	rl = ntfs_attr_find_vcn_nolock(mftbmp_ni,
-			(ll - 1) >> vol->cluster_size_bits, TRUE);
+			(ll - 1) >> vol->cluster_size_bits, NULL);
 	if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {
 		up_write(&mftbmp_ni->runlist.lock);
 		ntfs_error(vol->sb, "Failed to determine last allocated "
@@ -1354,7 +1355,8 @@ static int ntfs_mft_bitmap_extend_allocation_nolock(ntfs_volume *vol)
 		up_write(&vol->lcnbmp_lock);
 		ntfs_unmap_page(page);
 		/* Allocate a cluster from the DATA_ZONE. */
-		rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE);
+		rl2 = ntfs_cluster_alloc(vol, rl[1].vcn, 1, lcn, DATA_ZONE,
+				TRUE);
 		if (IS_ERR(rl2)) {
 			up_write(&mftbmp_ni->runlist.lock);
 			ntfs_error(vol->sb, "Failed to allocate a cluster for "
@@ -1738,7 +1740,7 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
 	ll = mft_ni->allocated_size;
 	read_unlock_irqrestore(&mft_ni->size_lock, flags);
 	rl = ntfs_attr_find_vcn_nolock(mft_ni,
-			(ll - 1) >> vol->cluster_size_bits, TRUE);
+			(ll - 1) >> vol->cluster_size_bits, NULL);
 	if (unlikely(IS_ERR(rl) || !rl->length || rl->lcn < 0)) {
 		up_write(&mft_ni->runlist.lock);
 		ntfs_error(vol->sb, "Failed to determine last allocated "
@@ -1779,7 +1781,8 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
 			nr > min_nr ? "default" : "minimal", (long long)nr);
 	old_last_vcn = rl[1].vcn;
 	do {
-		rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE);
+		rl2 = ntfs_cluster_alloc(vol, old_last_vcn, nr, lcn, MFT_ZONE,
+				TRUE);
 		if (likely(!IS_ERR(rl2)))
 			break;
 		if (PTR_ERR(rl2) != -ENOSPC || nr == min_nr) {
@@ -1951,20 +1954,21 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
 		NVolSetErrors(vol);
 		return ret;
 	}
-	a = ctx->attr;
-	a->data.non_resident.highest_vcn = cpu_to_sle64(old_last_vcn - 1);
+	ctx->attr->data.non_resident.highest_vcn =
+			cpu_to_sle64(old_last_vcn - 1);
 undo_alloc:
-	if (ntfs_cluster_free(mft_ni, old_last_vcn, -1) < 0) {
+	if (ntfs_cluster_free(mft_ni, old_last_vcn, -1, ctx) < 0) {
 		ntfs_error(vol->sb, "Failed to free clusters from mft data "
 				"attribute.%s", es);
 		NVolSetErrors(vol);
 	}
+	a = ctx->attr;
 	if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) {
 		ntfs_error(vol->sb, "Failed to truncate mft data attribute "
 				"runlist.%s", es);
 		NVolSetErrors(vol);
 	}
-	if (mp_rebuilt) {
+	if (mp_rebuilt && !IS_ERR(ctx->mrec)) {
 		if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
 				a->data.non_resident.mapping_pairs_offset),
 				old_alen - le16_to_cpu(
@@ -1981,6 +1985,10 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol)
 		}
 		flush_dcache_mft_record_page(ctx->ntfs_ino);
 		mark_mft_record_dirty(ctx->ntfs_ino);
+	} else if (IS_ERR(ctx->mrec)) {
+		ntfs_error(vol->sb, "Failed to restore attribute search "
+				"context.%s", es);
+		NVolSetErrors(vol);
 	}
 	if (ctx)
 		ntfs_attr_put_search_ctx(ctx);

fs/ntfs/super.c

@@ -1447,7 +1447,7 @@ static BOOL load_and_init_usnjrnl(ntfs_volume *vol)
 	if (unlikely(i_size_read(tmp_ino) < sizeof(USN_HEADER))) {
 		ntfs_error(vol->sb, "Found corrupt $UsnJrnl/$DATA/$Max "
 				"attribute (size is 0x%llx but should be at "
-				"least 0x%x bytes).", i_size_read(tmp_ino),
+				"least 0x%zx bytes).", i_size_read(tmp_ino),
 				sizeof(USN_HEADER));
 		return FALSE;
 	}