From: Andrei Popa <andrei.popa@i-neo.ro>
Date: Thu, 20 Sep 2012 14:42:11 +0000 (-0600)
Subject: Btrfs: make compress and nodatacow mount options mutually exclusive
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=bedb2cca7252d08c6ca3085826e30f65bdc3b54b;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

Btrfs: make compress and nodatacow mount options mutually exclusive

If a filesystem is mounted with compression and then remounted by adding nodatacow,
the compression is disabled but the compress flag is still visible.
Also, if a filesystem is mounted with nodatacow and then remounted with compression,
nodatacow flag is still present but it's not active.
This patch:
- removes compress flags and notifies that the compression has been disabled if the
  filesystem is mounted with nodatacow
- removes nodatacow and nodatasum flags if mounted with compress.

Signed-off-by: Andrei Popa <andrei.popa@i-neo.ro>
---

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 0fadcdba8ce..915ac14c206 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -413,7 +413,15 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 			btrfs_set_opt(info->mount_opt, NODATASUM);
 			break;
 		case Opt_nodatacow:
-			printk(KERN_INFO "btrfs: setting nodatacow\n");
+			if (!btrfs_test_opt(root, COMPRESS) ||
+				!btrfs_test_opt(root, FORCE_COMPRESS)) {
+					printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
+			} else {
+				printk(KERN_INFO "btrfs: setting nodatacow\n");
+			}
+			info->compress_type = BTRFS_COMPRESS_NONE;
+			btrfs_clear_opt(info->mount_opt, COMPRESS);
+			btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 			btrfs_set_opt(info->mount_opt, NODATACOW);
 			btrfs_set_opt(info->mount_opt, NODATASUM);
 			break;
@@ -428,10 +436,14 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 				compress_type = "zlib";
 				info->compress_type = BTRFS_COMPRESS_ZLIB;
 				btrfs_set_opt(info->mount_opt, COMPRESS);
+				btrfs_clear_opt(info->mount_opt, NODATACOW);
+				btrfs_clear_opt(info->mount_opt, NODATASUM);
 			} else if (strcmp(args[0].from, "lzo") == 0) {
 				compress_type = "lzo";
 				info->compress_type = BTRFS_COMPRESS_LZO;
 				btrfs_set_opt(info->mount_opt, COMPRESS);
+				btrfs_clear_opt(info->mount_opt, NODATACOW);
+				btrfs_clear_opt(info->mount_opt, NODATASUM);
 				btrfs_set_fs_incompat(info, COMPRESS_LZO);
 			} else if (strncmp(args[0].from, "no", 2) == 0) {
 				compress_type = "no";