This lets tarfs provide readahead/behind hints to the VFS, which helps
memory-mapped I/O performance, important when running faulting in
executables out of a tarfs mount as one might if tarfs is used to back
the root filesystem, for example. The improvement is particularly
noticeable when the backing tarball is zstd-compressed.
The implementation simply returns the extent of the virtual block
containing the target offset, clamped by the maximum I/O size. This is
perhaps simplistic; it effectively just chooses values that would
correspond to a single VOP_READ call in tarfs_read_file().
Reviewed by: des, kib
MFC after: 1 month
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D44626
There is no obvious reason to use a value smaller than that.
Reviewed by: des, kib
MFC after: 1 week
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D44627
Previously, we would error out if we encountered a global extended
header, because we don't know what it means. This doesn't really
matter though, and traditionally, tar implementations have either
ignored them or treated them as plain files, so just ignore them.
This allows tarfs to mount tar files created by `git archive`.
MFC after: 3 days
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Reviewed by: kevans
Differential Revision: https://reviews.freebsd.org/D44600
The checksum code assumed that struct ustar_header filled an entire
block and calculcated the checksum based on the size of the structure.
The header is in fact only 500 bytes long while the checksum covers
the entire block (“logical record” in POSIX terms). Add padding and
an assertion, and clean up the checksum code.
MFC after: 3 days
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D44226
* Reject hard or soft links with an empty target path. Currently, a
debugging kernel will hit an assertion in tarfs_lookup_path() while
a non-debugging kernel will happily create a link to the mount root.
* Use a temporary variable to store the result of the link target path,
and copy it to tnp->other only once we have found it to be valid.
Otherwise we error out after creating a reference to the target but
before incrementing the target's reference count, which results in a
use-after-free situation in the cleanup code.
* Correctly return ENOENT from tarfs_lookup_path() if the requested
path was not found and create_dirs is false. Luckily, existing
callers did not rely solely on the return value.
MFC after: 3 days
PR: 277360
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Reviewed by: sjg
Differential Revision: https://reviews.freebsd.org/D44161
Use it when possible, instead of separated flags.
No functional change intended.
Reviewed by: hselasky, erj
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D39466
We default to passing the path of the tar file to vfs_mountedfrom
so we can tell where a filesystem was mounted from.
However this can make the output of mount(8) hard to read.
Allow things like:
mount -t tarfs -o as=`basename $tar` $tar /mnt
so "as" is recorded instead of $tar
Reviewed by: des
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D39273
The previous fix was incorrect: we need to verify that the current node, if it exists, is not a directory, but we were checking the parent node instead. Address this, add more tests, and fix the test cleanup routines.
PR: 269519, 269561
Fixes: ae6cff8973
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D38645
* tarfs_alloc_mount(): Remove an unnecessary null check (CID 1504505) and an unused variable.
* tarfs_alloc_one(): Verify that the file size is not negative (CID 1504506). While there, also validate the mode, owner and group.
* tarfs_vget(), tarfs_zio_init(): Explicitly ignore return value from getnewvnode(), which cannot fail (CID 1504508)
* tarfs_lookup_path(): Fix a case where a specially-crafted tarball could trigger a null pointer dereference by first descending into, and then backing out of, a previously unknown directory. (CID 1504515)
* mktar: Construct a tarball that triggers the aforementioned null pointer dereference.
Reported by: Coverity
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D38463
Some of the code in sys/fs/tarfs/tarfs_io.c is not specific to zstd, but is still only used when some form of decompression is enabled. Put it behind #ifdef TARFS_ZIO to silence warnings.
Sponsored by: Juniper Networks, Inc.
Sponsored by: Klara, Inc.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D38415
