determine the endianness of the `struct fs *o' superblock from o->fs_magic
and set needswap as necessary, rather than trusting the caller to get
it right. invariably, almost every caller of ffs_sb_swap() was calling it
with ns set to the wrong value for ns anyway!
ansi KNF ffs_bswap.c declarations whilst here.
this fixes all sorts of problems when trying to use other-endian file systems,
notably the kernel trying to access memory *way* off, possibly corrupting or
panicing, and userland programs SEGVing and/or corrupting things (e.g,
"fsck_ffs -B" to swap a file system endianness).
whilst the previous rev of ffs_bswap.c (1.10, 2000/12/23) made this problem
worse, i suspect that the problem was always there and previous versions
just happened not to trash things at the wrong time.
FFS_EI should now be a lot more stable.
the current in-core master superblock, and fix them up if
they're incorrect. Move the code that writes the alternate
superblocks if (cvtlevel || doswap) into pass 5 for efficiency.
Reviewd by Charles Hannum, and used by me to fix up a curdled
file system.
Some years ago I made it O(n^2).
Someone helpfully made it O(n^4) again.
Today I'm making it O(n).
If that's not good enough, I don't know what else to do. B-)
Technical details:
* The graph traversal in propagate() is modified to be able to start from any
point in the tree. To handle certain exceptional cases, it is also modified
to work in two passes, marking the tree with a special tag and then changing
it to DFOUND.
* The reconnect case now modifies the child/sibling pointers and calls
propagate() to propagate the connection state starting with the reconnected
directory.
Pray that you never encounter a file system trashed enough for this to matter.
too damn small) by setting a minimum (1024) and maximum (maxino + 1). This
prevents certain operations getting REALLY slow when -b is used, and also
avoids overallocating memory if the superblock is hosed.
Also, be a bit more conservative with the clean flag: don't mark the FS
clean when we know there may still be errors (user anserwed 'n' to
a question, or fsck says "you must rerun fsck").
