Building with -DMSDOSFS_DEBUG failed due to a format mismatch and
a variable that has been renamed but not updated in the printf()
parameter list.
(cherry picked from commit 2d8cf575d5)
fs/msdosfs: add tracking of free root directory entries
This update implements tallying of free directory entries during
create, delete, or rename operations on FAT12 and FAT16 file systems.
Prior to this change, the total number of root directory entries
was reported as number of inodes, but 0 as the number of free
inodes, causing system health monitoring software to warn about
a suspected disk full issue.
The FAT12 and FAT16 file systems provide a limited number of
root directory entries, e.g. 512 on typical hard disk formats.
The valid range of values is 1 to 65535, but the msdosfs code
will effectively round up "odd" values to the next multiple of 16
(e.g. 513 would allow for 528 root directory entries).
This update implements tracking of directory entries during create,
delete, or rename operations, with initial values determined by
scanning the directory when the file system is mounted.
Total and free directory entries are reported in the f_files and
f_ffree elements of struct statfs, despite differences in semantics
of these values:
- There is no limit on the number of files and directories that can
be created on a FAT file system. Only the root directory of FAT12
and FAT16 file systems is limited, any number of files can still be
created in sub-directories, even when 0 free "inodes" are reported.
- A single file can require 1 to 21 directory entries, depending on
the character set, structure, and length of the name. The DOS 8.3
style file name takes up 1 entry, and if the name does not comply
with the syntax of a DOS 8.3 file name, 1 additional entry is used
for each 13 characters of the file name. Since all these entries
have to be contiguous, it is possible that a file or directory with
a long name can not be created, despite a sufficient total number of
free directory entries.
- Renaming a file can require more directory entries than currently
allocated to store its long name, which may prevent an in-place
update of the name if more entries are needed. This may cause a
rename operation to fail if no contiguous range of free entries for
the new name can be found.
- The volume label is stored in a directory entry. An empty FAT file
system with a volume label will therefore show 1 used "inode" in
df.
- The perceentage of free inodes shown in df or monitoring tools does
only represent the state of the root directory of a FAT12 or FAT16
file system. Neither does a reported value of 0% free inodes does
prevent files from being created in sub-directories, nor does a
value of 50% free inodes guarantee that even a single file with
a "long" name can be created in the root directory (if every other
directory entry is occupied and there are no 2 contiguous entries).
The statfs(2) and df(1) man pages have been updated with a notice
regarding the possibly different semantics of values reported as
total and free inodes for non-Unix file systems.
PR: 270053
Reported by: Ben Woods <woodsb02@freebsd.org>
Approved by: mckusick
Differential Revision: https://reviews.freebsd.org/D38987
(cherry picked from commit c33db74b53)
fs/msdosfs: Fix potential panic and size calculations
Some combinations of FAT12 file system parameters could cause a kernel
panic due to an unmapped access if the size of the FAT was larger than
the CPU page size. The reason is that FAT12 uses 3 bytes to store
2 FAT pointers, leading to partial FAT pointers at the end of buffers
of a size that is not a multiple of 3.
With a typical page size of 4 KB, this caused the FAT entry at byte
offsets 4095 and 4096 to cross the page boundary, with only the first
page mapped. This was fixed by adjusting the mapping to always cover
both bytes of each FAT entry.
Testing revealed 2 other inconsistencies that are fixed by this commit:
1) The calculation of the size of the data area did not take into
account the fact that the first two data block numbers are reserved
and that the data area starts with block 2. This could cause a
FAT12 file system created with the maximum supported number of
blocks to be incorrectly identified as FAT16.
2) The root directory does not take up space in the data area of a
FAT12 or FAT16 file system, since it is placed into a reserved
area outside of that data area. This commits makes stat() report
the logical size of the root directory, but with 0 blocks allocated
from the data area.
PR: 270587
Reviewed by: mckusick
Differential Revision: https://reviews.freebsd.org/D39386
(cherry picked from commit 0728695c63)
While here, complete the libxo conversion and switch return value to standard constants.
MFC after: 1 week
Sponsored by: Klara, Inc.
Differential revision: https://reviews.freebsd.org/D38097
(cherry picked from commit c968598479)
Before:
devfs 2 2 0 100% 0 0 100% /dev
After:
devfs 2 2 0 100% 0 0 - /dev
The previous behaviour was confusing for end users and many monitoring tools
Note the linux df tools is also using the same syntax '-' for such filesystem
MFC After: 2 weeks
Reviewed by: manu, emaste, imp
Differential Revision: https://reviews.freebsd.org/D34515
(cherry picked from commit 2eee44bd5e)
The df command provides a -l option to exclude all non-local file
systems and a -t option with a (positive or negative) list of file
system types to display.
This commit adds support for a combination of -l and -t. If both are
specified, the parameter list of the -t option is applied on top of
the selection of öocal file systems (independently of the order of
the -l and -t options).
E.g., "df -t noprocfs,sysfs -l" will select all local file systems
except those of type procfs and sysfs.
(cherry picked from commit f0fd4a32c4)
This was marked deprecated in r329092, over two and a half years ago.
This functionality is also buggy per PR 237368.
PR: 237368
Reviewed by: brooks, cem, emaste, imp
Differential Revision: https://reviews.freebsd.org/D27197
* Add EXAMPLES section with four simple examples.
* Simplify -H flag description. This makes easy to see the difference between
this flag and -h
* While here, fix .Tn deprecated macro.
Approved by: manpages (bcr@)
Differential Revision: https://reviews.freebsd.org/D26662
to see how much space it on them.
Adjust MOUNT_CHAR_DEVS to allow the free space of already mounted
devices to be displayed and report an appropriate error if the
device isn't mounted.
Reviewed by: cem
MFC after: 1 week
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D8801
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
Rather than producing a misleading error message when duplicate -l flags are
provided to df(1), simply ignore extra flags and proceed as if only one was
specified. This seems most reasonable given the usage for -l:
-l Only display information about locally-mounted file systems.
l and t flags still conflict, as before.
PR: 208169
Reported by: by at reorigin.com
Reviewed by: allanjude
Note: tcsh(1) has a MK_TCSH=no test, so this should be a separate
package, which requires pre-install/post-install scripts, to be
added later.
Sponsored by: The FreeBSD Foundation
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp
the free(3) of mntbuf ... again. There's no point in doing
useless extra work when we're about to exit.
See also r240565.
Not reading file history: uqs
While here:
- use NULL in the context of pointers
- use memset instead of bzero throughout the file
- free memory to appease clang static analyzer
Found by: Coverity Scan (the UNINIT one)