[patch 14/27] check for O_DIRECT capability in open(), not write()

From: Andrew Morton (akpm@zip.com.au)
Date: Thu Jul 04 2002 - 18:54:33 EST


For O_DIRECT opens we're currently checking that the fs supports
O_DIRECT at write(2)-time.

This is a forward-port of Andrea's patch which moves the check to
open() time. Seems more sensible.

 fs/fcntl.c | 5 +++++
 fs/open.c | 8 ++++++++
 mm/filemap.c | 2 --
 3 files changed, 13 insertions(+), 2 deletions(-)

--- 2.5.24/fs/fcntl.c~o_direct-open-check Thu Jul 4 16:17:24 2002
+++ 2.5.24-akpm/fs/fcntl.c Thu Jul 4 16:17:24 2002
@@ -245,6 +245,11 @@ static int setfl(int fd, struct file * f
         }
 
         if (arg & O_DIRECT) {
+ if (inode->i_mapping && inode->i_mapping->a_ops) {
+ if (!inode->i_mapping->a_ops->direct_IO)
+ return -EINVAL;
+ }
+
                 /*
                  * alloc_kiovec() can sleep and we are only serialized by
                  * the big kernel lock here, so abuse the i_sem to serialize
--- 2.5.24/fs/open.c~o_direct-open-check Thu Jul 4 16:17:24 2002
+++ 2.5.24-akpm/fs/open.c Thu Jul 4 16:17:24 2002
@@ -665,6 +665,14 @@ struct file *dentry_open(struct dentry *
         }
         f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
 
+ /* NB: we're sure to have correct a_ops only after f_op->open */
+ if (f->f_flags & O_DIRECT) {
+ error = -EINVAL;
+ if (inode->i_mapping && inode->i_mapping->a_ops)
+ if (!inode->i_mapping->a_ops->direct_IO)
+ goto cleanup_all;
+ }
+
         return f;
 
 cleanup_all:
--- 2.5.24/mm/filemap.c~o_direct-open-check Thu Jul 4 16:17:24 2002
+++ 2.5.24-akpm/mm/filemap.c Thu Jul 4 16:22:09 2002
@@ -1121,8 +1121,6 @@ static ssize_t generic_file_direct_IO(in
         retval = -EINVAL;
         if ((offset & blocksize_mask) || (count & blocksize_mask))
                 goto out_free;
- if (!mapping->a_ops->direct_IO)
- goto out_free;
 
         /*
          * Flush to disk exclusively the _data_, metadata must remain

-
-
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This archive was generated by hypermail 2b29 : Sun Jul 07 2002 - 22:00:14 EST