6 files changed, 31 insertions, 21 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 1d2ad15f15..6d2a99c13d 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -2,20 +2,18 @@ ToDo/Notes:
         - Find and fix bugs.
         - Checkpoint or disable the user space journal ($UsnJrnl).
         - In between ntfs_prepare/commit_write, need exclusion between
-          simultaneous file extensions. Need perhaps an NInoResizeUnderway()
-          flag which we can set in ntfs_prepare_write() and clear again in
-          ntfs_commit_write(). Just have to be careful in readpage/writepage,
-          as well as in truncate, that we play nice... We might need to have
-          a data_size field in the ntfs_inode to store the real attribute
-          length. Also need to be careful with initialized_size extention in
+          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...
-          OTOH, perhaps i_sem, which is held accross generic_file_write is
-          sufficient for synchronisation here. We then just need to make sure
-          ntfs_readpage/writepage/truncate interoperate properly with us.
-          UPDATE: The above is all ok as it is due to i_sem held.  The only
-          thing that needs to be checked is ntfs_writepage() which does not
-          hold i_sem.  It cannot change i_size but it needs to cope with a
-          concurrent i_size change.
+          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.
         - 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
@@ -31,6 +29,11 @@ ToDo/Notes:
           compiled without debug.  This avoids a possible denial of service
           attack.  Thanks to Carl-Daniel Hailfinger from SuSE for pointing this
           out.
+        - Use i_size_read() in fs/ntfs/attrib.c::ntfs_attr_set().
+        - Use i_size_read() in fs/ntfs/logfile.c::ntfs_{check,empty}_logfile().
+        - Use i_size_read() once and then use the cached value in
+          fs/ntfs/lcnalloc.c::ntfs_cluster_alloc().
+        - Use i_size_read() in fs/ntfs/file.c::ntfs_file_open().
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 
diff --git a/fs/ntfs/Makefile b/fs/ntfs/Makefile
index 7b66381a0b..f8c97d4122 100644
--- a/fs/ntfs/Makefile
+++ b/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=\"2.1.22\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.23-WIP\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 1ff7f90a18..7d668466dc 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -1127,6 +1127,10 @@ int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
  * byte offset @ofs inside the attribute with the constant byte @val.
  *
  * This function is effectively like memset() applied to an ntfs attribute.
+ * Note thie function actually only operates on the page cache pages belonging
+ * to the ntfs attribute and it marks them dirty after doing the memset().
+ * Thus it relies on the vm dirty page write code paths to cause the modified
+ * pages to be written to the mft record/disk.
  *
  * Return 0 on success and -errno on error.  An error code of -ESPIPE means
  * that @ofs + @cnt were outside the end of the attribute and no write was
@@ -1155,7 +1159,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
         end = ofs + cnt;
         end_ofs = end & ~PAGE_CACHE_MASK;
         /* If the end is outside the inode size return -ESPIPE. */
-        if (unlikely(end > VFS_I(ni)->i_size)) {
+        if (unlikely(end > i_size_read(VFS_I(ni)))) {
                 ntfs_error(vol->sb, "Request exceeds end of attribute.");
                 return -ESPIPE;
         }
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index db8713ea0d..e0f530ce6b 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -47,7 +47,7 @@
 static int ntfs_file_open(struct inode *vi, struct file *filp)
 {
         if (sizeof(unsigned long) < 8) {
-                if (vi->i_size > MAX_LFS_FILESIZE)
+                if (i_size_read(vi) > MAX_LFS_FILESIZE)
                         return -EFBIG;
         }
         return generic_file_open(vi, filp);
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
index 23fd911078..5346596fa8 100644
--- a/fs/ntfs/lcnalloc.c
+++ b/fs/ntfs/lcnalloc.c
@@ -140,6 +140,7 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
         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;
         s64 clusters;
+        loff_t i_size;
         struct inode *lcnbmp_vi;
         runlist_element *rl = NULL;
         struct address_space *mapping;
@@ -249,6 +250,7 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
         clusters = count;
         rlpos = rlsize = 0;
         mapping = lcnbmp_vi->i_mapping;
+        i_size = i_size_read(lcnbmp_vi);
         while (1) {
                 ntfs_debug("Start of outer while loop: done_zones 0x%x, "
                                 "search_zone %i, pass %i, zone_start 0x%llx, "
@@ -263,7 +265,7 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
                 last_read_pos = bmp_pos >> 3;
                 ntfs_debug("last_read_pos 0x%llx.",
                                 (unsigned long long)last_read_pos);
-                if (last_read_pos > lcnbmp_vi->i_size) {
+                if (last_read_pos > i_size) {
                         ntfs_debug("End of attribute reached.  "
                                         "Skipping to zone_pass_done.");
                         goto zone_pass_done;
@@ -287,8 +289,8 @@ runlist_element *ntfs_cluster_alloc(ntfs_volume *vol, const VCN start_vcn,
                 buf_size = last_read_pos & ~PAGE_CACHE_MASK;
                 buf = page_address(page) + buf_size;
                 buf_size = PAGE_CACHE_SIZE - buf_size;
-                if (unlikely(last_read_pos + buf_size > lcnbmp_vi->i_size))
-                        buf_size = lcnbmp_vi->i_size - last_read_pos;
+                if (unlikely(last_read_pos + buf_size > i_size))
+                        buf_size = i_size - last_read_pos;
                 buf_size <<= 3;
                 lcn = bmp_pos & 7;
                 bmp_pos &= ~7;
diff --git a/fs/ntfs/logfile.c b/fs/ntfs/logfile.c
index 5e280abafa..e680dd0cdb 100644
--- a/fs/ntfs/logfile.c
+++ b/fs/ntfs/logfile.c
@@ -443,7 +443,7 @@ BOOL ntfs_check_logfile(struct inode *log_vi)
         /* An empty $LogFile must have been clean before it got emptied. */
         if (NVolLogFileEmpty(vol))
                 goto is_empty;
-        size = log_vi->i_size;
+        size = i_size_read(log_vi);
         /* Make sure the file doesn't exceed the maximum allowed size. */
         if (size > MaxLogFileSize)
                 size = MaxLogFileSize;
@@ -689,7 +689,8 @@ BOOL ntfs_empty_logfile(struct inode *log_vi)
         if (!NVolLogFileEmpty(vol)) {
                 int err;
                 
-                err = ntfs_attr_set(NTFS_I(log_vi), 0, log_vi->i_size, 0xff);
+                err = ntfs_attr_set(NTFS_I(log_vi), 0, i_size_read(log_vi),
+                                0xff);
                 if (unlikely(err)) {
                         ntfs_error(vol->sb, "Failed to fill $LogFile with "
                                         "0xff bytes (error code %i).", err);