gfs2: Eliminate ip->i_gh

commit 1b223f7065bc7d89c4677c27381817cc95b117a8 upstream

Now that gfs2_file_buffered_write is the only remaining user of
ip->i_gh, we can move the glock holder to the stack (or rather, use the
one we already have on the stack); there is no need for keeping the
holder in the inode anymore.

This is slightly complicated by the fact that we're using ip->i_gh for
the statfs inode in gfs2_file_buffered_write as well.  Writing to the
statfs inode isn't very common, so allocate the statfs holder
dynamically when needed.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index f652688..288a789 100644 (file)
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -877,16 +877,25 @@ out_uninit:
        return written ? written : ret;
 }
 
-static ssize_t gfs2_file_buffered_write(struct kiocb *iocb, struct iov_iter *from)
+static ssize_t gfs2_file_buffered_write(struct kiocb *iocb,
+                                       struct iov_iter *from,
+                                       struct gfs2_holder *gh)
 {
        struct file *file = iocb->ki_filp;
        struct inode *inode = file_inode(file);
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_sbd *sdp = GFS2_SB(inode);
+       struct gfs2_holder *statfs_gh = NULL;
        ssize_t ret;
 
-       gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
-       ret = gfs2_glock_nq(&ip->i_gh);
+       if (inode == sdp->sd_rindex) {
+               statfs_gh = kmalloc(sizeof(*statfs_gh), GFP_NOFS);
+               if (!statfs_gh)
+                       return -ENOMEM;
+       }
+
+       gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, gh);
+       ret = gfs2_glock_nq(gh);
        if (ret)
                goto out_uninit;
 
@@ -894,7 +903,7 @@ static ssize_t gfs2_file_buffered_write(struct kiocb *iocb, struct iov_iter *fro
                struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 
                ret = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
-                                        GL_NOCACHE, &m_ip->i_gh);
+                                        GL_NOCACHE, statfs_gh);
                if (ret)
                        goto out_unlock;
        }
@@ -905,16 +914,15 @@ static ssize_t gfs2_file_buffered_write(struct kiocb *iocb, struct iov_iter *fro
        if (ret > 0)
                iocb->ki_pos += ret;
 
-       if (inode == sdp->sd_rindex) {
-               struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
-
-               gfs2_glock_dq_uninit(&m_ip->i_gh);
-       }
+       if (inode == sdp->sd_rindex)
+               gfs2_glock_dq_uninit(statfs_gh);
 
 out_unlock:
-       gfs2_glock_dq(&ip->i_gh);
+       gfs2_glock_dq(gh);
 out_uninit:
-       gfs2_holder_uninit(&ip->i_gh);
+       gfs2_holder_uninit(gh);
+       if (statfs_gh)
+               kfree(statfs_gh);
        return ret;
 }
 
@@ -969,7 +977,7 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
                        goto out_unlock;
 
                iocb->ki_flags |= IOCB_DSYNC;
-               buffered = gfs2_file_buffered_write(iocb, from);
+               buffered = gfs2_file_buffered_write(iocb, from, &gh);
                if (unlikely(buffered <= 0)) {
                        if (!ret)
                                ret = buffered;
@@ -990,7 +998,7 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
                if (!ret || ret2 > 0)
                        ret += ret2;
        } else {
-               ret = gfs2_file_buffered_write(iocb, from);
+               ret = gfs2_file_buffered_write(iocb, from, &gh);
                if (likely(ret > 0))
                        ret = generic_write_sync(iocb, ret);
        }

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 58b7bac..ca42d31 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -387,9 +387,8 @@ struct gfs2_inode {
        u64 i_generation;
        u64 i_eattr;
        unsigned long i_flags;          /* GIF_... */
-       struct gfs2_glock *i_gl; /* Move into i_gh? */
+       struct gfs2_glock *i_gl;
        struct gfs2_holder i_iopen_gh;
-       struct gfs2_holder i_gh; /* for prepare/commit_write only */
        struct gfs2_qadata *i_qadata; /* quota allocation data */
        struct gfs2_holder i_rgd_gh;
        struct gfs2_blkreserv i_res; /* rgrp multi-block reservation */