Linux 4.14.111

[thirdparty/kernel/stable-queue.git] / releases / 4.14.111 / ext4-cleanup-bh-release-code-in-ext4_ind_remove_space.patch

diff --git a/releases/4.14.111/ext4-cleanup-bh-release-code-in-ext4_ind_remove_space.patch b/releases/4.14.111/ext4-cleanup-bh-release-code-in-ext4_ind_remove_space.patch
new file mode 100644 (file)
index 0000000..47ca587
--- /dev/null
+++ b/releases/4.14.111/ext4-cleanup-bh-release-code-in-ext4_ind_remove_space.patch
@@ -0,0 +1,163 @@
+From 5e86bdda41534e17621d5a071b294943cae4376e Mon Sep 17 00:00:00 2001
+From: "zhangyi (F)" <yi.zhang@huawei.com>
+Date: Sat, 23 Mar 2019 11:56:01 -0400
+Subject: ext4: cleanup bh release code in ext4_ind_remove_space()
+
+From: zhangyi (F) <yi.zhang@huawei.com>
+
+commit 5e86bdda41534e17621d5a071b294943cae4376e upstream.
+
+Currently, we are releasing the indirect buffer where we are done with
+it in ext4_ind_remove_space(), so we can see the brelse() and
+BUFFER_TRACE() everywhere.  It seems fragile and hard to read, and we
+may probably forget to release the buffer some day.  This patch cleans
+up the code by putting of the code which releases the buffers to the
+end of the function.
+
+Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+Reviewed-by: Jan Kara <jack@suse.cz>
+Cc: Jari Ruusu <jari.ruusu@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/ext4/indirect.c |   47 ++++++++++++++++++++++-------------------------
+ 1 file changed, 22 insertions(+), 25 deletions(-)
+
+--- a/fs/ext4/indirect.c
++++ b/fs/ext4/indirect.c
+@@ -1219,6 +1219,7 @@ int ext4_ind_remove_space(handle_t *hand
+       ext4_lblk_t offsets[4], offsets2[4];
+       Indirect chain[4], chain2[4];
+       Indirect *partial, *partial2;
++      Indirect *p = NULL, *p2 = NULL;
+       ext4_lblk_t max_block;
+       __le32 nr = 0, nr2 = 0;
+       int n = 0, n2 = 0;
+@@ -1260,7 +1261,7 @@ int ext4_ind_remove_space(handle_t *hand
+               }
+ 
+ 
+-              partial = ext4_find_shared(inode, n, offsets, chain, &nr);
++              partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);
+               if (nr) {
+                       if (partial == chain) {
+                               /* Shared branch grows from the inode */
+@@ -1285,13 +1286,11 @@ int ext4_ind_remove_space(handle_t *hand
+                               partial->p + 1,
+                               (__le32 *)partial->bh->b_data+addr_per_block,
+                               (chain+n-1) - partial);
+-                      BUFFER_TRACE(partial->bh, "call brelse");
+-                      brelse(partial->bh);
+                       partial--;
+               }
+ 
+ end_range:
+-              partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
++              partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
+               if (nr2) {
+                       if (partial2 == chain2) {
+                               /*
+@@ -1321,16 +1320,14 @@ end_range:
+                                          (__le32 *)partial2->bh->b_data,
+                                          partial2->p,
+                                          (chain2+n2-1) - partial2);
+-                      BUFFER_TRACE(partial2->bh, "call brelse");
+-                      brelse(partial2->bh);
+                       partial2--;
+               }
+               goto do_indirects;
+       }
+ 
+       /* Punch happened within the same level (n == n2) */
+-      partial = ext4_find_shared(inode, n, offsets, chain, &nr);
+-      partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
++      partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);
++      partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
+ 
+       /* Free top, but only if partial2 isn't its subtree. */
+       if (nr) {
+@@ -1387,15 +1384,7 @@ end_range:
+                                          partial->p + 1,
+                                          partial2->p,
+                                          (chain+n-1) - partial);
+-                      while (partial > chain) {
+-                              BUFFER_TRACE(partial->bh, "call brelse");
+-                              brelse(partial->bh);
+-                      }
+-                      while (partial2 > chain2) {
+-                              BUFFER_TRACE(partial2->bh, "call brelse");
+-                              brelse(partial2->bh);
+-                      }
+-                      return 0;
++                      goto cleanup;
+               }
+ 
+               /*
+@@ -1410,8 +1399,6 @@ end_range:
+                                          partial->p + 1,
+                                          (__le32 *)partial->bh->b_data+addr_per_block,
+                                          (chain+n-1) - partial);
+-                      BUFFER_TRACE(partial->bh, "call brelse");
+-                      brelse(partial->bh);
+                       partial--;
+               }
+               if (partial2 > chain2 && depth2 <= depth) {
+@@ -1419,11 +1406,21 @@ end_range:
+                                          (__le32 *)partial2->bh->b_data,
+                                          partial2->p,
+                                          (chain2+n2-1) - partial2);
+-                      BUFFER_TRACE(partial2->bh, "call brelse");
+-                      brelse(partial2->bh);
+                       partial2--;
+               }
+       }
++
++cleanup:
++      while (p && p > chain) {
++              BUFFER_TRACE(p->bh, "call brelse");
++              brelse(p->bh);
++              p--;
++      }
++      while (p2 && p2 > chain2) {
++              BUFFER_TRACE(p2->bh, "call brelse");
++              brelse(p2->bh);
++              p2--;
++      }
+       return 0;
+ 
+ do_indirects:
+@@ -1431,7 +1428,7 @@ do_indirects:
+       switch (offsets[0]) {
+       default:
+               if (++n >= n2)
+-                      return 0;
++                      break;
+               nr = i_data[EXT4_IND_BLOCK];
+               if (nr) {
+                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
+@@ -1439,7 +1436,7 @@ do_indirects:
+               }
+       case EXT4_IND_BLOCK:
+               if (++n >= n2)
+-                      return 0;
++                      break;
+               nr = i_data[EXT4_DIND_BLOCK];
+               if (nr) {
+                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
+@@ -1447,7 +1444,7 @@ do_indirects:
+               }
+       case EXT4_DIND_BLOCK:
+               if (++n >= n2)
+-                      return 0;
++                      break;
+               nr = i_data[EXT4_TIND_BLOCK];
+               if (nr) {
+                       ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
+@@ -1456,5 +1453,5 @@ do_indirects:
+       case EXT4_TIND_BLOCK:
+               ;
+       }
+-      return 0;
++      goto cleanup;
+ }