[PATCH 04/29] GFS2: Lock i_mutex and use a local gfs2_holder for fallocate

From: Steven Whitehouse
Date: Tue Apr 01 2014 - 05:24:53 EST


From: Bob Peterson <rpeterso@xxxxxxxxxx>

This patch causes GFS2 to lock the i_mutex during fallocate. It
also switches from using a dinode's inode glock to using a local
holder like the other GFS2 i_operations.

Signed-off-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index efc078f..6c79408 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -811,6 +811,8 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
loff_t max_chunk_size = UINT_MAX & bsize_mask;
+ struct gfs2_holder gh;
+
next = (next + 1) << sdp->sd_sb.sb_bsize_shift;

/* We only support the FALLOC_FL_KEEP_SIZE mode */
@@ -831,8 +833,10 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
if (error)
return error;

- gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
- error = gfs2_glock_nq(&ip->i_gh);
+ mutex_lock(&inode->i_mutex);
+
+ gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+ error = gfs2_glock_nq(&gh);
if (unlikely(error))
goto out_uninit;

@@ -900,9 +904,10 @@ out_trans_fail:
out_qunlock:
gfs2_quota_unlock(ip);
out_unlock:
- gfs2_glock_dq(&ip->i_gh);
+ gfs2_glock_dq(&gh);
out_uninit:
- gfs2_holder_uninit(&ip->i_gh);
+ gfs2_holder_uninit(&gh);
+ mutex_unlock(&inode->i_mutex);
return error;
}

--
1.8.3.1

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