NFS: Fix up the fsync code

Christoph points out that the VFS will always flush out data before calling
nfs_fsync(), so we can dispense with a full call to nfs_wb_all(), and
replace that with a simpler call to nfs_commit_inode().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2010-07-31 14:29:06 -04:00
parent 77041ed9b4
commit af7fa16506

View File

@ -201,38 +201,12 @@ static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
return loff;
}
/*
* Helper for nfs_file_flush() and nfs_file_fsync()
*
* Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
* disk, but it retrieves and clears ctx->error after synching, despite
* the two being set at the same time in nfs_context_set_write_error().
* This is because the former is used to notify the _next_ call to
* nfs_file_write() that a write error occured, and hence cause it to
* fall back to doing a synchronous write.
*/
static int nfs_do_fsync(struct nfs_open_context *ctx, struct inode *inode)
{
int have_error, status;
int ret = 0;
have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
status = nfs_wb_all(inode);
have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
if (have_error)
ret = xchg(&ctx->error, 0);
if (!ret)
ret = status;
return ret;
}
/*
* Flush all dirty pages, and check for write errors.
*/
static int
nfs_file_flush(struct file *file, fl_owner_t id)
{
struct nfs_open_context *ctx = nfs_file_open_context(file);
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
@ -245,7 +219,7 @@ nfs_file_flush(struct file *file, fl_owner_t id)
return 0;
/* Flush writes to the server and return any errors */
return nfs_do_fsync(ctx, inode);
return vfs_fsync(file, 0);
}
static ssize_t
@ -320,6 +294,13 @@ nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
* Flush any dirty pages for this process, and check for write errors.
* The return status from this call provides a reliable indication of
* whether any write errors occurred for this process.
*
* Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
* disk, but it retrieves and clears ctx->error after synching, despite
* the two being set at the same time in nfs_context_set_write_error().
* This is because the former is used to notify the _next_ call to
* nfs_file_write() that a write error occured, and hence cause it to
* fall back to doing a synchronous write.
*/
static int
nfs_file_fsync(struct file *file, int datasync)
@ -327,13 +308,23 @@ nfs_file_fsync(struct file *file, int datasync)
struct dentry *dentry = file->f_path.dentry;
struct nfs_open_context *ctx = nfs_file_open_context(file);
struct inode *inode = dentry->d_inode;
int have_error, status;
int ret = 0;
dprintk("NFS: fsync file(%s/%s) datasync %d\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
datasync);
nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
return nfs_do_fsync(ctx, inode);
have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
status = nfs_commit_inode(inode, FLUSH_SYNC);
have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
if (have_error)
ret = xchg(&ctx->error, 0);
if (!ret)
ret = status;
return ret;
}
/*
@ -639,7 +630,7 @@ static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
/* Return error values for O_DSYNC and IS_SYNC() */
if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode);
int err = vfs_fsync(iocb->ki_filp, 0);
if (err < 0)
result = err;
}
@ -675,7 +666,7 @@ static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
written = ret;
if (ret >= 0 && nfs_need_sync_write(filp, inode)) {
int err = nfs_do_fsync(nfs_file_open_context(filp), inode);
int err = vfs_fsync(filp, 0);
if (err < 0)
ret = err;
}