To check a directory's in-use bitmap bit by bit, we use
a pointer to an 8 bit wide unsigned value.
The index used to dereference this pointer is calculated
by shifting the bit index right 3 bits. Then we do a
logical AND with the bit# represented by the lower 3
bits of the bit index.
This is an idiomatic way of iterating through a bit map
with simple bitwise operations.
This commit fixes the bug that we only checked bits
3:0 of each 8 bit chunk, because we only used bits 1:0
of the bit index for the bit# in the current 8 bit value.
This resulted in files not being returned by getdirentries(2).
Change the type of the bit map pointer from `char *' to
`u_int8_t *'.
perfect solution as the lower vm object can change at unpredictable times
if our lower vp happens to be on another unionfs, etc.
Submitted by: Oleg Sharoiko <os@rsu.ru>
Since the name cache is case-sensitive and msdosfs isn't,
creating a file 'foo' won't invalidate a negative entry for 'FOO'.
There are similar problems related to 8.3 filenames.
A better solution is to override VOP_LOOKUP with a method that
canonicalizes the name, then calls vfs_cache_lookup(). Unfortunately,
it's not quite that simple because vfs_cache_lookup() will call
msdosfs_lookup() on a cache miss, and msdosfs_lookup() needs a way to
get at the original component name.
than WIN_CHARS bytes, we shift the suffix (previous substrings) upwards
by the amount this substring exceeds its WIN_CHARS slot. Profiling shows
this change is indistinguishable from the previous code at 95% confidence.
This bug would result in attempts to access or create files or directories
with multi-byte characters returning an error but no data loss.
Reported and tested by: avatar
MFC after: 3 days
- Only unlock the directory if this is a DOTDOT lookup. Previously this
code could have deadlocked if there was a DOTDOT lookup with LOCKPARENT
set and another thread was locking the other way up the tree.
Sponsored by: Isilon Systems, Inc.
handled in vfs_lookup.c. This code was missing PDIRUNLOCK use prior
to the removal of PDIRUNLOCK in rev 1.73 of vfs_lookup.c.
Sponsored by: Isilon Systems, Inc.
handled in vfs_lookup.c. This code was missing PDIRUNLOCK use prior
to the removal of PDIRUNLOCK in rev 1.73 of vfs_lookup.c.
Sponsored by: Isilon Systems, Inc.
- In the ISDOTDOT case we have to unlock the dvp before locking the child,
if this fails we must relock dvp before returning an error. This was
missing before.
Sponsored by: Isilon Systems, Inc.
- Network filesystems are written with a special idiom that checks the
cache first, and may even unlock dvp before discovering that a network
round-trip is required to resolve the name. I believe dvp is prevented
from being recycled even in the forced unmount case by the shared lock
on the mount point. If not, this code should grow checks for VI_DOOMED
after it relocks dvp or it will access NULL v_data fields.
Sponsored by: Isilon Systems, Inc.
these filesystems will support shared locks until they are explicitly
modified to do so. Careful review must be done to ensure that this
is safe for each individual filesystem.
Sponsored by: Isilon Systems, Inc.
these filesystems will support shared locks until they are explicitly
modified to do so. Careful review must be done to ensure that this
is safe for each individual filesystem.
Sponsored by: Isilon Systems, Inc.
