[XFS] wire up ->open for directories

Currently there's no ->open method set for directories on XFS.  That
means we don't perform any check for opening too large directories
without O_LARGEFILE, we don't check for shut down filesystems, and we
don't actually do the readahead for the first block in the directory.

Instead of just setting the directories open routine to xfs_file_open
we merge the shutdown check directly into xfs_file_open and create
a new xfs_dir_open that first calls xfs_file_open and then performs
the readahead for block 0.

(First sent on September 29th)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>

1 files changed, 31 insertions, 3 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 3fee790f138b..72fc8d8c8bc1 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -38,6 +38,7 @@
 #include "xfs_rw.h"
 #include "xfs_ioctl32.h"
 #include "xfs_vnodeops.h"
+#include "xfs_da_btree.h"
 
 #include <linux/dcache.h>
 #include <linux/smp_lock.h>
@@ -169,11 +170,37 @@ xfs_file_splice_write_invis(
 STATIC int
 xfs_file_open(
         struct inode    *inode,
-        struct file     *filp)
+        struct file     *file)
 {
-        if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
+        if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
                 return -EFBIG;
-        return -xfs_open(XFS_I(inode));
+        if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
+                return -EIO;
+        return 0;
+}
+
+STATIC int
+xfs_dir_open(
+        struct inode    *inode,
+        struct file     *file)
+{
+        struct xfs_inode *ip = XFS_I(inode);
+        int             mode;
+        int             error;
+
+        error = xfs_file_open(inode, file);
+        if (error)
+                return error;
+
+        /*
+         * If there are any blocks, read-ahead block 0 as we're almost
+         * certain to have the next operation be a read there.
+         */
+        mode = xfs_ilock_map_shared(ip);
+        if (ip->i_d.di_nextents > 0)
+                xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK);
+        xfs_iunlock(ip, mode);
+        return 0;
 }
 
 STATIC int
@@ -345,6 +372,7 @@ const struct file_operations xfs_invis_file_operations = {
 
 
 const struct file_operations xfs_dir_file_operations = {
+        .open           = xfs_dir_open,
         .read           = generic_read_dir,
         .readdir        = xfs_file_readdir,
         .llseek         = generic_file_llseek,