Page-cached I/O is used for regular files, and is initiated by VFS
users such as userland and NFS.
Buffer-cached I/O is used for directories and symlinks, and is issued
only internally by UFS.
New UFS routine ufs_bufio replaces vn_rdwr for internal use.
ufs_bufio is implemented by new UFS operations uo_bufrd/uo_bufwr,
which sit in ufs_readwrite.c alongside the VOP_READ/VOP_WRITE
implementations.
I preserved the code as much as possible and will leave further
simplification for future commits. I kept the ulfs_readwrite.c
copypasta close to ufs_readwrite.c in case we ever want to merge them
back; likewise ext2fs_readwrite.c.
No externally visible semantic change. All atf fs tests still pass.
- Change ffs_valloc to return an inode number.
- Remove now obsolete UFS operations UFS_VALLOC and UFS_VFREE.
- Make ufs_makeinode private to ufs_vnops.c and pass vattr instead of mode.
- instead of always calling DPRINTF with __func__, put __func__ directly
in the macro
- ffs_mountfs(): rename fsblockloc -> fs_sblockloc, initialize fs_sbsize
to zero
No real functional change
move the swap code inside the loop.
'fs->fs_sbsize' is swapped twice: the first time in order to get the
correct superblock size, and later when swapping the whole superblock
structure. As a result, we need to check 'fs->fs_sbsize' twice.
This:
- fixes my previous changes for swapped FSes
- allows the kernel to look for other superblock locations if the
current superblock is not validated
And now:
- ffs_superblock_validate() takes only one argument: the fs structure
- 'fs_bsize' is unused, so delete it
Add some comments to explain a bit what we are doing.
superblock location may have changed. But that implies that we don't
handle the possibility that its size may have changed either.
Therefore: add a check to ensure the size hasn't changed. Otherwise the
mismatch leads to a memory corruption with kmem.
When unmount failed, for instance because the mount is still busy,
UFS1 extended attributes structures were left freed while the kernel
assumes extended attributes were still enabled. This led to using
UFS1 extended attributes structures after free. With LOCKDEBUG, with
quickly triggers a panic.
The problem is fixed by:
1) clear MNT_EXTATTR flag after extended attributes structures are freed
2) attempt to restart extended attributes after failed unmount
2) set MNT_EXTATTR correctly after extended attributes restart
As a side effect, extended attribute structures are now only initialized
when extended attributes are started for the filesystem.
find.
The filesystem ones all call genfs_eopnotsupp - right now I am only
implementing the plumbing and we can implement fallocate and/or
fdiscard for files later.
The device ones call spec_fallocate (which is also genfs_eopnotsupp)
and spec_fdiscard, which dispatches to the device-level op.
The fifo ones all call vn_fifo_bypass, which also ends up being
EOPNOTSUPP.
need to vget() vnodes that we are not interested at, and optimize locking
a bit. Iterator changes reviewed by Hannken (thanks), the rest of the bugs
are mine.
- vcache_get() retrieves a referenced and initialised vnode / fs node pair.
- vcache_remove() removes a vnode / fs node pair from the cache.
On cache miss vcache_get() calls new vfs operation vfs_loadvnode() to
initialise a vnode / fs node pair. This call is guaranteed exclusive,
no other thread will try to load this vnode / fs node pair.
Convert ufs/ext2fs, ufs/ffs and ufs/mfs to use this interface.
Remove now unused ufs/ufs_ihash
Discussed on tech-kern.
Welcome to 6.99.41
