Merge branch 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...

Pull btrfs fixes from Chris Mason:
 "This has two last minute fixes. The highest priority here is a
  regression fix for the decompression code, but we also fixed up a
  problem with the 32-bit compat ioctls.

  The decompression bug could hand back the wrong data on big reads when
  zlib was used. I have a larger cleanup to make the math here less
  error prone, but at this stage in the release Omar's patch is the best
  choice"

* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix btrfs_decompress_buf2page()
  btrfs: fix btrfs_compat_ioctl failures on non-compat ioctls

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 7f390849343b3e42b9399c2ac58b948c87944902..c4444d6f439f676cee59a20322d0f88fcb3cc4a3 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1024,6 +1024,7 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
        unsigned long buf_offset;
        unsigned long current_buf_start;
        unsigned long start_byte;
+       unsigned long prev_start_byte;
        unsigned long working_bytes = total_out - buf_start;
        unsigned long bytes;
        char *kaddr;
@@ -1071,26 +1072,34 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
                if (!bio->bi_iter.bi_size)
                        return 0;
                bvec = bio_iter_iovec(bio, bio->bi_iter);
-
+               prev_start_byte = start_byte;
                start_byte = page_offset(bvec.bv_page) - disk_start;
 
                /*
-                * make sure our new page is covered by this
-                * working buffer
+                * We need to make sure we're only adjusting
+                * our offset into compression working buffer when
+                * we're switching pages.  Otherwise we can incorrectly
+                * keep copying when we were actually done.
                 */
-               if (total_out <= start_byte)
-                       return 1;
+               if (start_byte != prev_start_byte) {
+                       /*
+                        * make sure our new page is covered by this
+                        * working buffer
+                        */
+                       if (total_out <= start_byte)
+                               return 1;
 
-               /*
-                * the next page in the biovec might not be adjacent
-                * to the last page, but it might still be found
-                * inside this working buffer. bump our offset pointer
-                */
-               if (total_out > start_byte &&
-                   current_buf_start < start_byte) {
-                       buf_offset = start_byte - buf_start;
-                       working_bytes = total_out - start_byte;
-                       current_buf_start = buf_start + buf_offset;
+                       /*
+                        * the next page in the biovec might not be adjacent
+                        * to the last page, but it might still be found
+                        * inside this working buffer. bump our offset pointer
+                        */
+                       if (total_out > start_byte &&
+                           current_buf_start < start_byte) {
+                               buf_offset = start_byte - buf_start;
+                               working_bytes = total_out - start_byte;
+                               current_buf_start = buf_start + buf_offset;
+                       }
                }
        }
 

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 33f967d30b2ad1d555015baea2bccc5eba05d1d5..21e51b0ba188a37be6b71cab9218a8b9457b86f8 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5653,6 +5653,10 @@ long btrfs_ioctl(struct file *file, unsigned int
 #ifdef CONFIG_COMPAT
 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
+       /*
+        * These all access 32-bit values anyway so no further
+        * handling is necessary.
+        */
        switch (cmd) {
        case FS_IOC32_GETFLAGS:
                cmd = FS_IOC_GETFLAGS;
@@ -5663,8 +5667,6 @@ long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        case FS_IOC32_GETVERSION:
                cmd = FS_IOC_GETVERSION;
                break;
-       default:
-               return -ENOIOCTLCMD;
        }
 
        return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));