NTFS: Use i_size_read() once and then use the cached value in

      fs/ntfs/lcnalloc.c::ntfs_cluster_alloc().

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>

2 files changed, 7 insertions, 3 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index b1a949401be3..ff0d9b132df8 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -31,6 +31,8 @@ ToDo/Notes:
           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().
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
index 23fd911078b1..5346596fa871 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;