This is the bulk of PR #17345
The general approach is to use a run time deteriminable value
for DIRBLKSIZ. Additional allowances are included for using
MAXSYMLINKLEN with FS_42INODEFMT and a shift in the cylinder group
cluster summary count array. Support is added for managing
the Apple UFS volume label.
This merge changes the device switch tables from static array to
dynamically generated by config(8).
- All device switches is defined as a constant structure in device drivers.
- The new grammer ``device-major'' is introduced to ``files''.
device-major <prefix> char <num> [block <num>] [<rules>]
- All device major numbers must be listed up in port dependent majors.<arch>
by using this grammer.
- Added the new naming convention.
The name of the device switch must be <prefix>_[bc]devsw for auto-generation
of device switch tables.
- The backward compatibility of loading block/character device
switch by LKM framework is broken. This is necessary to convert
from block/character device major to device name in runtime and vice versa.
- The restriction to assign device major by LKM is completely removed.
We don't need to reserve LKM entries for dynamic loading of device switch.
- In compile time, device major numbers list is packed into the kernel and
the LKM framework will refer it to assign device major number dynamically.
exist on an on-disk inode, we keep a record of its size in struct inode,
which is updated when we write the block to disk. The cleaner routines
thus have ready access to what size is the correct size for this block,
on disk.
Fixed a related bug: if a file with fragments is being cleaned
(fragments being cleaned) at the same time it is being extended beyond
NDADDR blocks, we could write a bogus FINFO record that has a frag in the
middle; when it was cleaned this would give back bogus file data. Don't
write the indirect blocks in this case, since there is no need.
lfs_fragextend and lfs_truncate no longer require the seglock, but instead
take a shared lock, which the seglock locks exclusively.
processes don't have to wait for one another to finish (e.g., nfsd seems
to be a little happier now, though I haven't measured the difference).
Synchronous checkpoints, however, must always wait for all i/o to finish.
Take the contents of the callback functions and have them run in thread
context instead (aiodoned thread). lfs_iocount no longer has to be
protected in splbio(), and quite a bit less of the segment construction
loop needs to be in splbio() as well.
If lfs_markv is handed a block that is not the correct size according to
the inode, refuse to process it. (Formerly it was extended to the "correct"
size.) This is possibly more prone to deadlock, but less prone to corruption.
lfs_segclean now outright refuses to clean segments that appear to have live
bytes in them. Again this may be more prone to deadlock but avoids
corruption.
Replace ufsspec_close and ufsfifo_close with LFS equivalents; this means
that no UFS functions need to know about LFS_ITIMES any more. Remove
the reference from ufs/inode.h.
Tested on i386, test-compiled on alpha.
this enables one to recover data from a failing disk (where the read failure
is a hardware problem) while avoiding corrupting the fs further (in the case
where the read failure is due to a misconfiguration).
as well as bi_daddr. This lets the cleaner have an idea of what the size
of this block was at the time it was written without having to refer to
a segment header (e.g., in the file coalescing case).
Tested on i386.
enough to be useful, and broadening it so that it did would have meant
that operations possibly requiring synchronous disk activity would have
to be done in splbio(). This clearly was not going to work.
Worked around this in the LFS case by having lfs_cluster_callback put an
extra hold on the vnode before calling biodone(), and taking the hold
off without HOLDRELE's problematic list swapping. lfs_vunref() will take
care of that---in thread context---on the next write if need be.
Also, ensure that the list walking in lfs_{writevnodes,segunlock,gather}
takes into account the possibility that the list may change
underneath it (possibly because it itself deleted an element).
Tested on i386, test-compiled on alpha.
I found while making sure there weren't any new ones.
* Make the write clusters keep track of the buffers whose blocks they contain.
This should make it possible to (1) write clusters using a page mapping
instead of malloc, if desired, and (2) schedule blocks for rewriting
(somewhere else) if a write error occurs. Code is present to use
pagemove() to construct the clusters but that is untested and will go away
anyway in favor of page mapping.
* DEBUG now keeps a log of Ifile writes, so that any lingering instances of
the "dirty bufs" problem can be properly debugged.
* Keep track of whether the Ifile has been dirtied by various routines that
can be called by lfs_segwrite, and loop on that until it is clean, for
a checkpoint. Checkpoints need to be squeaky clean.
* Warn the user (once) if the Ifile grows larger than is reasonable for their
buffer cache. Both lfs_mountfs and lfs_unmount check since the Ifile can
grow.
* If an inode is not found in a disk block, try rereading the block, under
the assumption that the block was copied to a cluster and then freed.
* Protect WRITEINPROG() with splbio() to fix a hang in lfs_update.
- If VOP_ACCESS fails when updating mount, we will vrele() twice.
- The check for update-only flags in mp->mnt_flag when not updating
case is bogus. If we really want to check, we need to see flags in
ufs_args, but I'm not sure if it is really necessary.
- The credential passed to ffs_reload was credential of when looking
up mount point, but now it is credential of when looking up device
node. Anyway, it may be current process's credential.
