Merge branch 'ufs-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull ufs fixes from Al Viro:
 "Fix assorted ufs bugs: a couple of deadlocks, fs corruption in
  truncate(), oopsen on tail unpacking and truncate when racing with
  vmscan, mild fs corruption (free blocks stats summary buggered, *BSD
  fsck would complain and fix), several instances of broken logics
  around reserved blocks (starting with "check almost never triggers
  when it should" and then there are issues with sufficiently large
  UFS2)"

[ Note: ufs hasn't gotten any loving in a long time, because nobody
  really seems to use it. These ufs fixes are triggered by people
  actually caring now, not some sudden influx of new bugs.  - Linus ]

* 'ufs-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ufs_truncate_blocks(): fix the case when size is in the last direct block
  ufs: more deadlock prevention on tail unpacking
  ufs: avoid grabbing ->truncate_mutex if possible
  ufs_get_locked_page(): make sure we have buffer_heads
  ufs: fix s_size/s_dsize users
  ufs: fix reserved blocks check
  ufs: make ufs_freespace() return signed
  ufs: fix logics in "ufs: make fsck -f happy"

1 files changed, 32 insertions, 15 deletions

diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index da553ffec85b..9f4590261134 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -401,13 +401,20 @@ static int ufs_getfrag_block(struct inode *inode, sector_t fragment, struct buff
 	u64 phys64 = 0;
 	unsigned frag = fragment & uspi->s_fpbmask;
 
-	if (!create) {
-		phys64 = ufs_frag_map(inode, offsets, depth);
-		if (phys64)
-			map_bh(bh_result, sb, phys64 + frag);
-		return 0;
-	}
+	phys64 = ufs_frag_map(inode, offsets, depth);
+	if (!create)
+		goto done;
 
+	if (phys64) {
+		if (fragment >= UFS_NDIR_FRAGMENT)
+			goto done;
+		read_seqlock_excl(&UFS_I(inode)->meta_lock);
+		if (fragment < UFS_I(inode)->i_lastfrag) {
+			read_sequnlock_excl(&UFS_I(inode)->meta_lock);
+			goto done;
+		}
+		read_sequnlock_excl(&UFS_I(inode)->meta_lock);
+	}
         /* This code entered only while writing ....? */
 
 	mutex_lock(&UFS_I(inode)->truncate_mutex);
@@ -451,6 +458,11 @@ out:
 	}
 	mutex_unlock(&UFS_I(inode)->truncate_mutex);
 	return err;
+
+done:
+	if (phys64)
+		map_bh(bh_result, sb, phys64 + frag);
+	return 0;
 }
 
 static int ufs_writepage(struct page *page, struct writeback_control *wbc)
@@ -874,7 +886,6 @@ static inline void free_data(struct to_free *ctx, u64 from, unsigned count)
 	ctx->to = from + count;
 }
 
-#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
 
 static void ufs_trunc_direct(struct inode *inode)
@@ -1112,19 +1123,24 @@ static void ufs_truncate_blocks(struct inode *inode)
 	struct super_block *sb = inode->i_sb;
 	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 	unsigned offsets[4];
-	int depth = ufs_block_to_path(inode, DIRECT_BLOCK, offsets);
+	int depth;
 	int depth2;
 	unsigned i;
 	struct ufs_buffer_head *ubh[3];
 	void *p;
 	u64 block;
 
-	if (!depth)
-		return;
+	if (inode->i_size) {
+		sector_t last = (inode->i_size - 1) >> uspi->s_bshift;
+		depth = ufs_block_to_path(inode, last, offsets);
+		if (!depth)
+			return;
+	} else {
+		depth = 1;
+	}
 
-	/* find the last non-zero in offsets[] */
 	for (depth2 = depth - 1; depth2; depth2--)
-		if (offsets[depth2])
+		if (offsets[depth2] != uspi->s_apb - 1)
 			break;
 
 	mutex_lock(&ufsi->truncate_mutex);
@@ -1133,9 +1149,8 @@ static void ufs_truncate_blocks(struct inode *inode)
 		offsets[0] = UFS_IND_BLOCK;
 	} else {
 		/* get the blocks that should be partially emptied */
-		p = ufs_get_direct_data_ptr(uspi, ufsi, offsets[0]);
+		p = ufs_get_direct_data_ptr(uspi, ufsi, offsets[0]++);
 		for (i = 0; i < depth2; i++) {
-			offsets[i]++;	/* next branch is fully freed */
 			block = ufs_data_ptr_to_cpu(sb, p);
 			if (!block)
 				break;
@@ -1146,7 +1161,7 @@ static void ufs_truncate_blocks(struct inode *inode)
 				write_sequnlock(&ufsi->meta_lock);
 				break;
 			}
-			p = ubh_get_data_ptr(uspi, ubh[i], offsets[i + 1]);
+			p = ubh_get_data_ptr(uspi, ubh[i], offsets[i + 1]++);
 		}
 		while (i--)
 			free_branch_tail(inode, offsets[i + 1], ubh[i], depth - i - 1);
@@ -1161,7 +1176,9 @@ static void ufs_truncate_blocks(struct inode *inode)
 			free_full_branch(inode, block, i - UFS_IND_BLOCK + 1);
 		}
 	}
+	read_seqlock_excl(&ufsi->meta_lock);
 	ufsi->i_lastfrag = DIRECT_FRAGMENT;
+	read_sequnlock_excl(&ufsi->meta_lock);
 	mark_inode_dirty(inode);
 	mutex_unlock(&ufsi->truncate_mutex);
 }