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| author | Christoph Hellwig <hch@infradead.org> | 2011-06-24 14:29:42 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-07-20 20:47:45 -0400 |
| commit | f9b5570d7fdedff32a2e78102bfb54cd1b12b289 (patch) | |
| tree | 0bbe650c809d96b25d746c400e316c3ad71b4097 /fs | |
| parent | 9ea7df534ed2a18157434a496a12cf073ca00c52 (diff) | |
| download | linux-stable-f9b5570d7fdedff32a2e78102bfb54cd1b12b289.tar.gz linux-stable-f9b5570d7fdedff32a2e78102bfb54cd1b12b289.tar.bz2 linux-stable-f9b5570d7fdedff32a2e78102bfb54cd1b12b289.zip | |
fs: simplify handling of zero sized reads in __blockdev_direct_IO
Reject zero sized reads as soon as we know our I/O length, and don't
borther with locks or allocations that might have to be cleaned up
otherwise.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/direct-io.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index ac5f164170e3..98ce3ac0d94b 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1200,6 +1200,10 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, } } + /* watch out for a 0 len io from a tricksy fs */ + if (rw == READ && end == offset) + return 0; + dio = kmalloc(sizeof(*dio), GFP_KERNEL); retval = -ENOMEM; if (!dio) @@ -1213,8 +1217,7 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, dio->flags = flags; if (dio->flags & DIO_LOCKING) { - /* watch out for a 0 len io from a tricksy fs */ - if (rw == READ && end > offset) { + if (rw == READ) { struct address_space *mapping = iocb->ki_filp->f_mapping; |