export RK_PA3

hc

2024-02-19 151fecfb72a0d602dfe79790602ef64b4e241574

 kernel/fs/super.c
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@@ -906,6 +906,7 @@
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 	struct super_block *sb = fc->root->d_sb;
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 	int retval;
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 	bool remount_ro = false;
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+	bool remount_rw = false;
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 	bool force = fc->sb_flags & SB_FORCE;
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911
 
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 	if (fc->sb_flags_mask & ~MS_RMT_MASK)
..
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@@ -922,7 +923,7 @@
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 		if (!(fc->sb_flags & SB_RDONLY) && bdev_read_only(sb->s_bdev))
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 			return -EACCES;
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 #endif
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-
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+		remount_rw = !(fc->sb_flags & SB_RDONLY) && sb_rdonly(sb);
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 		remount_ro = (fc->sb_flags & SB_RDONLY) && !sb_rdonly(sb);
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 	}
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929
 
..
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@@ -952,6 +953,14 @@
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 			if (retval)
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 				return retval;
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 		}
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+	} else if (remount_rw) {
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+		/*
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+		 * We set s_readonly_remount here to protect filesystem's
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+		 * reconfigure code from writes from userspace until
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+		 * reconfigure finishes.
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+		 */
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+		sb->s_readonly_remount = 1;
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+		smp_wmb();
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 	}
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 	if (fc->ops->reconfigure) {