Messages in this thread Patch in this message | | | Date | Mon, 06 Jun 2005 14:44:05 +0200 | From | Jan Blunck <> | Subject | Re: [PATCH] don't allow sys_readahead() on files opened with O_DIRECT |
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Christoph Hellwig wrote: > your check is wrong, it's testing whether the filesystem supports O_DIRECT, not > whether sys_readahead is used on a file descriptor that has been opened with O_DIRECT
D'oh! You're right.
Jan
do_readahead() doesn't make sense if the file is opened with O_DIRECT, since only the page cache is stuffed but never used.
Signed-off-by: Jan Blunck <j.blunck@tu-harburg.de>
mm/filemap.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletion(-)
Index: experimental-um/mm/filemap.c =================================================================== --- experimental-um.orig/mm/filemap.c +++ experimental-um/mm/filemap.c @@ -1110,7 +1110,8 @@ static ssize_t do_readahead(struct address_space *mapping, struct file *filp, unsigned long index, unsigned long nr) { - if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage) + if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage + || (filp->f_flags & O_DIRECT)) return -EINVAL; force_page_cache_readahead(mapping, filp, index, | |