[PATCH v4 01/21] NFS: Remove unnecessary inode locking in nfs_llseek_dir()

trondmy
2020-11-07T14:13:38Z

Remove the contentious inode lock, and instead provide thread safety
using the file->f_lock spinlock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/dir.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index cb52db9a0cfb..e56b1bd99537 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -955,7 +955,6 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)

static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
{
- struct inode *inode = file_inode(filp);
struct nfs_open_dir_context *dir_ctx = filp->private_data;

dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
@@ -967,15 +966,15 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
case SEEK_SET:
if (offset < 0)
return -EINVAL;
- inode_lock(inode);
+ spin_lock(&filp->f_lock);
break;
case SEEK_CUR:
if (offset == 0)
return filp->f_pos;
- inode_lock(inode);
+ spin_lock(&filp->f_lock);
offset += filp->f_pos;
if (offset < 0) {
- inode_unlock(inode);
+ spin_unlock(&filp->f_lock);
return -EINVAL;
}
}
@@ -987,7 +986,7 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
dir_ctx->dir_cookie = 0;
dir_ctx->duped = 0;
}
- inode_unlock(inode);
+ spin_unlock(&filp->f_lock);
return offset;
}

--
2.28.0