[PATCH] mm: Fix comment before truncate_setsize()

[PATCH] mm: Fix comment before truncate_setsize()

[Jan Kara]

XFS doesn't always hold i_mutex when calling truncate_setsize() and it
uses a different lock to serialize truncates and writes. So fix the
comment before truncate_setsize().

Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 mm/truncate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/truncate.c b/mm/truncate.c
index b248c0c8dcd1..ed33e8f811e9 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -715,8 +715,9 @@ EXPORT_SYMBOL(truncate_pagecache);
  * necessary) to @newsize. It will be typically be called from the filesystem's
  * setattr function when ATTR_SIZE is passed in.
  *
- * Must be called with inode_mutex held and before all filesystem specific
- * block truncation has been performed.
+ * Must be called with a lock serializing truncates and writes (generally
+ * i_mutex but e.g. xfs uses a different lock) and before all filesystem
+ * specific block truncation has been performed.
  */
 void truncate_setsize(struct inode *inode, loff_t newsize)
 {
-- 
1.8.1.4

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Re: [PATCH] mm: Fix comment before truncate_setsize()

[Dave Chinner]

On Wed, Nov 05, 2014 at 06:00:06PM +0100, Jan Kara wrote:
> XFS doesn't always hold i_mutex when calling truncate_setsize() and it
> uses a different lock to serialize truncates and writes. So fix the
> comment before truncate_setsize().
> 
> Reported-by: Jan Beulich <JBeulich@suse.com>
> Signed-off-by: Jan Kara <jack@suse.cz>

I'll pull this into the xfs tree with the other fix. SHould go to
linus tomorrow morning now that I've got all the XFS issues that
were holding it up sorted out.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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