From 7401aafd5019d32a888e5f27332cf580945574bf Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Sat, 26 Mar 2011 09:14:44 +1100 Subject: [PATCH] xfs: xfs_trans_read_buf() should return an error on failure When inside a transaction and we fail to read a buffer, xfs_trans_read_buf returns a null buffer pointer and no error. xfs_do_da_buf() checks the error return, but not the buffer, and as a result this read failure condition causes a panic when it attempts to dereference the non-existant buffer. Make xfs_trans_read_buf() return the same error for this situation regardless of whether it is in a transaction or not. This means every caller does not need to check both the error return and the buffer before proceeding to use the buffer. Signed-off-by: Dave Chinner Reviewed-by: Alex Elder --- fs/xfs/xfs_trans_buf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c index 3bea66132334..03b3b7f85a3b 100644 --- a/fs/xfs/xfs_trans_buf.c +++ b/fs/xfs/xfs_trans_buf.c @@ -383,7 +383,8 @@ xfs_trans_read_buf( bp = xfs_buf_read(target, blkno, len, flags | XBF_DONT_BLOCK); if (bp == NULL) { *bpp = NULL; - return 0; + return (flags & XBF_TRYLOCK) ? + 0 : XFS_ERROR(ENOMEM); } if (XFS_BUF_GETERROR(bp) != 0) { XFS_BUF_SUPER_STALE(bp);