UBIFS: add a superblock flag for free space fix-up
The 'space_fixup' flag can be set in the superblock of a new filesystem by
mkfs.ubifs to indicate that any eraseblocks with free space remaining should be
fixed-up the first time it's mounted (after which the flag is un-set). This
means that the UBIFS image has been flashed by a "dumb" flasher and the free
space has been actually programmed (writing all 0xFFs), so this free space
cannot be used. UBIFS fixes the free space up by re-writing the contents of all
LEBs with free space using the atomic LEB change UBI operation.
Artem: improved commit message, add some more commentaries to the code.
Signed-off-by: Matthew L. Creech <mlcreech@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index b5ba2ea..f46d77e 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -316,6 +316,8 @@
printk(KERN_DEBUG "\tflags %#x\n", sup_flags);
printk(KERN_DEBUG "\t big_lpt %u\n",
!!(sup_flags & UBIFS_FLG_BIGLPT));
+ printk(KERN_DEBUG "\t space_fixup %u\n",
+ !!(sup_flags & UBIFS_FLG_SPACE_FIXUP));
printk(KERN_DEBUG "\tmin_io_size %u\n",
le32_to_cpu(sup->min_io_size));
printk(KERN_DEBUG "\tleb_size %u\n",