Also make note of a cleaner limitation: it seems that when it goes to
coalesce discontiguous files, it mallocs an array with one BLOCK_INFO
for every block in the file. Therefore, with 64-bit LFS, on a 32-bit
platform it will be possible to have files large enough to overflow
the cleaner's address space. Currently these will be skipped and cause
warnings via syslog.
At some point someone should rewrite the logic to coalesce files to
use chunks of some reasonable size, as discontinuity between such
chunks is immaterial and mallocing this much space is silly and
fragile. Also, the kernel only accepts up to 65536 blocks at a time
for bmapv and markv, so processing more than this at once probably
isn't useful and may not even work currently. I don't want to change
this around just now as it's not entirely trivial.
Add pieces of support for using both superblock types where
convenient, and specifically to the superblock accessors, but don't
actually enable it anywhere.
First substantive step on PR 50000.
(This changes the rest of the code over; all the accessors were
already added.)
The difference between this commit and the previous one is arbitrary,
but the previous one passed the regression tests on its own so I'm
keeping it separate to help with any bisections that might be needed
in the future.
superblock. This will allow switching between 32/64 bit forms on the
fly; it will also allow handling LFS_EI reasonably tidily. (That
currently doesn't work on the superblock.)
It also gets rid of cpp abuse in the form of fake structure member
macros.
Also, instead of doing sleep/wakeup on &lfs_avail and &lfs_nextseg
inside the on-disk superblock, add extra elements to the in-memory
struct lfs for this. (XXX: these should be changed to condvars, but
not right now)
XXX: this migrates a structure needed by the lfs code in libsa (struct
salfs) into lfs.h, where it doesn't belong, but for the time being
this is necessary in order to allow the accessors (and the various
lfs macros and other goop that relies on them) to compile.
pollution. Specifically:
ROOTINO -> UFS_ROOTINO
WINO -> UFS_WINO
NXADDR -> UFS_NXADDR
NDADDR -> UFS_NDADDR
NIADDR -> UFS_NIADDR
MAXSYMLINKLEN -> UFS_MAXSYMLINKLEN
MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)
Sort out ext2fs's misuse of NDADDR and NIADDR; fortunately, these have
the same values in ext2fs and ffs.
No functional change intended.
the main loop. This is useful for very quickly executed lfs runs
such as those in tests, as an initialization phase cleaner may
prevent file system unmount.
a struct called kernelops, which contains standard system calls
for the normal case and rump system calls for the rump case.
Make it possible to run the lfs cleaner in a library fashion (taking
the quick route with the implementation).
run through copy-on-write. Call fscow_run() with valid data where possible.
The LP_UFSCOW hack is no longer needed to protect ffs_copyonwrite() against
endless recursion.
- Add a flag B_MODIFY to bread(), breada() and breadn(). If set the caller
intends to modify the buffer returned.
- Always run copy-on-write on buffers returned from ffs_balloc().
- Add new function ffs_getblk() that gets a buffer, assigns a new blkno,
may clear the buffer and runs copy-on-write. Process possible errors
from getblk() or fscow_run(). Part of PR kern/38664.
Welcome to 4.99.63
Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>
While touching all vptofh/fhtovp functions, get rid of VFS_MAXFIDSIZ,
version the getfh(2) syscall and explicitly pass the size available in
the filehandle from userland.
Discussed on tech-kern, with lots of help from yamt (thanks!).
matter how empty they are.
Note that if two blocks have the same inode and block number, they sort
the same (this should never happen, but if it does there's no reason to
have qsort scramble the list).
Add some diagnostic syslog messages for unusual cases.
In determining when to stop reading segments when counting bytes (-b flag),
total the sizes of the blocks we're actually writing instead of assuming
they are all full blocks: many could be fragments or inode blocks. This
increases the number of segments per Ifile write, markedly improving the
efficiency of the cleaner in the small file case.
indirect block when considering the cleaning of block numbers less
than NDADDR (which do not use indirect blocks).
Also, note the loss of only half a block per segment to fragmentation
when considering the benefit function, rather than a whole block.
cleaner, but with more legible code.
Includes code for reading and writing to the raw disk device (so that an
unmounted fs could be cleaned), for the use of a single daemon to clean
multiple filesystems to save on resources, and for recording the old
contents of cleaned segments to offline storage for regression testing of
the LFS system as a whole; though these new features are not properly
tested at this point.
dholland