From: Ralph Boehme <slow@samba.org>
Date: Wed, 20 May 2020 21:01:16 +0000 (+0200)
Subject: vfs_commit: implement SMB_VFS_OPENAT()
X-Git-Tag: ldb-2.2.0~395
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9173b5fdac30e51e8fa59f30789f75fb91f83f6f;p=thirdparty%2Fsamba.git

vfs_commit: implement SMB_VFS_OPENAT()

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---

diff --git a/source3/modules/vfs_commit.c b/source3/modules/vfs_commit.c
index 408c90c46a0..010a86cab95 100644
--- a/source3/modules/vfs_commit.c
+++ b/source3/modules/vfs_commit.c
@@ -248,6 +248,82 @@ static int commit_open(
         return fd;
 }
 
+static int commit_openat(struct vfs_handle_struct *handle,
+			 const struct files_struct *dirfsp,
+			 const struct smb_filename *smb_fname,
+			 files_struct *fsp,
+			 int flags,
+			 mode_t mode)
+{
+        off_t dthresh;
+	const char *eof_mode;
+        struct commit_info *c = NULL;
+        int fd;
+
+        /* Don't bother with read-only files. */
+        if ((flags & O_ACCMODE) == O_RDONLY) {
+                return SMB_VFS_NEXT_OPENAT(handle,
+					   dirfsp,
+					   smb_fname,
+					   fsp,
+					   flags,
+					   mode);
+        }
+
+        /* Read and check module configuration */
+        dthresh = conv_str_size(lp_parm_const_string(SNUM(handle->conn),
+                                        MODULE, "dthresh", NULL));
+
+	eof_mode = lp_parm_const_string(SNUM(handle->conn),
+                                        MODULE, "eof mode", "none");
+
+        if (dthresh > 0 || !strequal(eof_mode, "none")) {
+                c = VFS_ADD_FSP_EXTENSION(
+			handle, fsp, struct commit_info, NULL);
+                /* Process main tunables */
+                if (c) {
+                        c->dthresh = dthresh;
+                        c->dbytes = 0;
+                        c->on_eof = EOF_NONE;
+                        c->eof = 0;
+                }
+        }
+        /* Process eof_mode tunable */
+        if (c) {
+                if (strequal(eof_mode, "hinted")) {
+                        c->on_eof = EOF_HINTED;
+                } else if (strequal(eof_mode, "growth")) {
+                        c->on_eof = EOF_GROWTH;
+                }
+        }
+
+        fd = SMB_VFS_NEXT_OPENAT(handle, dirfsp, smb_fname, fsp, flags, mode);
+	if (fd == -1) {
+		VFS_REMOVE_FSP_EXTENSION(handle, fsp);
+		return fd;
+	}
+
+        /* EOF commit modes require us to know the initial file size. */
+        if (c && (c->on_eof != EOF_NONE)) {
+                SMB_STRUCT_STAT st;
+		/*
+		 * Setting the fd of the FSP is a hack
+		 * but also practiced elsewhere -
+		 * needed for calling the VFS.
+		 */
+		fsp->fh->fd = fd;
+		if (SMB_VFS_FSTAT(fsp, &st) == -1) {
+			int saved_errno = errno;
+			SMB_VFS_CLOSE(fsp);
+			errno = saved_errno;
+                        return -1;
+                }
+		c->eof = st.st_ex_size;
+        }
+
+        return fd;
+}
+
 static ssize_t commit_pwrite(
         vfs_handle_struct * handle,
         files_struct *      fsp,
@@ -376,6 +452,7 @@ static int commit_ftruncate(
 
 static struct vfs_fn_pointers vfs_commit_fns = {
         .open_fn = commit_open,
+        .openat_fn = commit_openat,
         .close_fn = commit_close,
         .pwrite_fn = commit_pwrite,
         .pwrite_send_fn = commit_pwrite_send,