4 files changed, 56 insertions, 5 deletions

diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c
index f708c45d5f66..29f11e10a7c7 100644
--- a/fs/affs/amigaffs.c
+++ b/fs/affs/amigaffs.c
@@ -420,24 +420,51 @@ affs_mode_to_prot(struct inode *inode)
 	u32 prot = AFFS_I(inode)->i_protect;
 	umode_t mode = inode->i_mode;
 
+	/*
+	 * First, clear all RWED bits for owner, group, other.
+	 * Then, recalculate them afresh.
+	 *
+	 * We'll always clear the delete-inhibit bit for the owner, as that is
+	 * the classic single-user mode AmigaOS protection bit and we need to
+	 * stay compatible with all scenarios.
+	 *
+	 * Since multi-user AmigaOS is an extension, we'll only set the
+	 * delete-allow bit if any of the other bits in the same user class
+	 * (group/other) are used.
+	 */
+	prot &= ~(FIBF_NOEXECUTE | FIBF_NOREAD
+		  | FIBF_NOWRITE | FIBF_NODELETE
+		  | FIBF_GRP_EXECUTE | FIBF_GRP_READ
+		  | FIBF_GRP_WRITE   | FIBF_GRP_DELETE
+		  | FIBF_OTR_EXECUTE | FIBF_OTR_READ
+		  | FIBF_OTR_WRITE   | FIBF_OTR_DELETE);
+
+	/* Classic single-user AmigaOS flags. These are inverted. */
 	if (!(mode & 0100))
 		prot |= FIBF_NOEXECUTE;
 	if (!(mode & 0400))
 		prot |= FIBF_NOREAD;
 	if (!(mode & 0200))
 		prot |= FIBF_NOWRITE;
+
+	/* Multi-user extended flags. Not inverted. */
 	if (mode & 0010)
 		prot |= FIBF_GRP_EXECUTE;
 	if (mode & 0040)
 		prot |= FIBF_GRP_READ;
 	if (mode & 0020)
 		prot |= FIBF_GRP_WRITE;
+	if (mode & 0070)
+		prot |= FIBF_GRP_DELETE;
+
 	if (mode & 0001)
 		prot |= FIBF_OTR_EXECUTE;
 	if (mode & 0004)
 		prot |= FIBF_OTR_READ;
 	if (mode & 0002)
 		prot |= FIBF_OTR_WRITE;
+	if (mode & 0007)
+		prot |= FIBF_OTR_DELETE;
 
 	AFFS_I(inode)->i_protect = prot;
 }
diff --git a/fs/affs/file.c b/fs/affs/file.c
index a26a0f96c119..d91b0133d95d 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -429,6 +429,24 @@ static int affs_write_begin(struct file *file, struct address_space *mapping,
 	return ret;
 }
 
+static int affs_write_end(struct file *file, struct address_space *mapping,
+			  loff_t pos, unsigned int len, unsigned int copied,
+			  struct page *page, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	int ret;
+
+	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+
+	/* Clear Archived bit on file writes, as AmigaOS would do */
+	if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
+		AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
+		mark_inode_dirty(inode);
+	}
+
+	return ret;
+}
+
 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
 {
 	return generic_block_bmap(mapping,block,affs_get_block);
@@ -438,7 +456,7 @@ const struct address_space_operations affs_aops = {
 	.readpage = affs_readpage,
 	.writepage = affs_writepage,
 	.write_begin = affs_write_begin,
-	.write_end = generic_write_end,
+	.write_end = affs_write_end,
 	.direct_IO = affs_direct_IO,
 	.bmap = _affs_bmap
 };
@@ -795,6 +813,12 @@ done:
 	if (tmp > inode->i_size)
 		inode->i_size = AFFS_I(inode)->mmu_private = tmp;
 
+	/* Clear Archived bit on file writes, as AmigaOS would do */
+	if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
+		AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
+		mark_inode_dirty(inode);
+	}
+
 err_first_bh:
 	unlock_page(page);
 	put_page(page);
diff --git a/fs/affs/inode.c b/fs/affs/inode.c
index a346cf7659f1..044412110b52 100644
--- a/fs/affs/inode.c
+++ b/fs/affs/inode.c
@@ -93,7 +93,7 @@ struct inode *affs_iget(struct super_block *sb, unsigned long ino)
 	case ST_ROOT:
 		inode->i_uid = sbi->s_uid;
 		inode->i_gid = sbi->s_gid;
-		/* fall through */
+		fallthrough;
 	case ST_USERDIR:
 		if (be32_to_cpu(tail->stype) == ST_USERDIR ||
 		    affs_test_opt(sbi->s_flags, SF_SETMODE)) {
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 890b44874f0f..c6c2a513ec92 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -474,7 +474,7 @@ got_root:
 	case MUFS_INTLFFS:
 	case MUFS_DCFFS:
 		affs_set_opt(sbi->s_flags, SF_MUFS);
-		/* fall thru */
+		fallthrough;
 	case FS_INTLFFS:
 	case FS_DCFFS:
 		affs_set_opt(sbi->s_flags, SF_INTL);
@@ -486,7 +486,7 @@ got_root:
 		break;
 	case MUFS_OFS:
 		affs_set_opt(sbi->s_flags, SF_MUFS);
-		/* fall through */
+		fallthrough;
 	case FS_OFS:
 		affs_set_opt(sbi->s_flags, SF_OFS);
 		sb->s_flags |= SB_NOEXEC;
@@ -494,7 +494,7 @@ got_root:
 	case MUFS_DCOFS:
 	case MUFS_INTLOFS:
 		affs_set_opt(sbi->s_flags, SF_MUFS);
-		/* fall through */
+		fallthrough;
 	case FS_DCOFS:
 	case FS_INTLOFS:
 		affs_set_opt(sbi->s_flags, SF_INTL);