1 files changed, 46 insertions, 29 deletions
diff --git a/upstream/fedora-40/man5/btrfs.5 b/upstream/fedora-40/man5/btrfs.5
index 208aa24b..8f00c0be 100644
--- a/upstream/fedora-40/man5/btrfs.5
+++ b/upstream/fedora-40/man5/btrfs.5
@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "BTRFS" "5" "Feb 14, 2024" "6.7.1" "BTRFS"
+.TH "BTRFS" "5" "Mar 26, 2024" "6.8" "BTRFS"
 .SH NAME
 btrfs \- topics about the BTRFS filesystem (mount options, supported file attributes and other)
 .SH DESCRIPTION
@@ -70,7 +70,7 @@ storage model, hardware considerations
 .SS BTRFS SPECIFIC MOUNT OPTIONS
 .sp
 This section describes mount options specific to BTRFS.  For the generic mount
-options please refer to \fBmount(8)\fP manual page. The options are sorted alphabetically
+options please refer to \fI\%mount(8)\fP manual page. The options are sorted alphabetically
 (discarding the \fIno\fP prefix).
 .sp
 \fBNOTE:\fP
@@ -95,7 +95,7 @@ have been applied.
 (default: on)
 .sp
 Enable/disable support for POSIX Access Control Lists (ACLs).  See the
-\fBacl(5)\fP manual page for more information about ACLs.
+\fI\%acl(5)\fP manual page for more information about ACLs.
 .sp
 The support for ACL is build\-time configurable (BTRFS_FS_POSIX_ACL) and
 mount fails if \fIacl\fP is requested but the feature is not compiled in.
@@ -228,7 +228,7 @@ If compression is enabled, \fInodatacow\fP and \fInodatasum\fP are disabled.
 .sp
 Enable data copy\-on\-write for newly created files.
 \fINodatacow\fP implies \fInodatasum\fP, and disables \fIcompression\fP\&. All files created
-under \fInodatacow\fP are also set the NOCOW file attribute (see \fBchattr(1)\fP).
+under \fInodatacow\fP are also set the NOCOW file attribute (see \fI\%chattr(1)\fP).
 .sp
 \fBNOTE:\fP
 .INDENT 7.0
@@ -247,7 +247,7 @@ at the cost of potential partial writes, in case the write is interrupted
 Enable data checksumming for newly created files.
 \fIDatasum\fP implies \fIdatacow\fP, i.e. the normal mode of operation. All files created
 under \fInodatasum\fP inherit the \(dqno checksums\(dq property, however there\(aqs no
-corresponding file attribute (see \fBchattr(1)\fP).
+corresponding file attribute (see \fI\%chattr(1)\fP).
 .sp
 \fBNOTE:\fP
 .INDENT 7.0
@@ -599,7 +599,7 @@ Historically, any user could create a snapshot even if he was not owner
 of the source subvolume, the subvolume deletion has been restricted for that
 reason. The subvolume creation has been restricted but this mount option is
 still required. This is a usability issue.
-Since 4.18, the \fBrmdir(2)\fP syscall can delete an empty subvolume just like an
+Since 4.18, the \fI\%rmdir(2)\fP syscall can delete an empty subvolume just like an
 ordinary directory. Whether this is possible can be detected at runtime, see
 \fIrmdir_subvol\fP feature in \fIFILESYSTEM FEATURES\fP\&.
 .UNINDENT
@@ -635,7 +635,7 @@ previous use of the \fIinode_cache\fP option can be removed by
 .UNINDENT
 .SS NOTES ON GENERIC MOUNT OPTIONS
 .sp
-Some of the general mount options from \fBmount(8)\fP that affect BTRFS and are
+Some of the general mount options from \fI\%mount(8)\fP that affect BTRFS and are
 worth mentioning.
 .INDENT 0.0
 .TP
@@ -771,7 +771,7 @@ the filesystem contains or contained a RAID56 profile of block groups
 .B rmdir_subvol
 (since: 4.18)
 .sp
-indicate that \fBrmdir(2)\fP syscall can delete an empty subvolume just like an
+indicate that \fI\%rmdir(2)\fP syscall can delete an empty subvolume just like an
 ordinary directory. Note that this feature only depends on the kernel version.
 .TP
 .B skinny_metadata
@@ -813,8 +813,8 @@ sequentially, see section \fI\%ZONED MODE\fP
 .SH SWAPFILE SUPPORT
 .sp
 A swapfile, when active, is a file\-backed swap area.  It is supported since kernel 5.0.
-Use \fBswapon(8)\fP to activate it, until then (respectively again after deactivating it
-with \fBswapoff(8)\fP) it\(aqs just a normal file (with NODATACOW set), for which the special
+Use \fI\%swapon(8)\fP to activate it, until then (respectively again after deactivating it
+with \fI\%swapoff(8)\fP) it\(aqs just a normal file (with NODATACOW set), for which the special
 restrictions for active swapfiles don\(aqt apply.
 .sp
 There are some limitations of the implementation in BTRFS and Linux swap
@@ -1447,9 +1447,9 @@ pattern detection, byte frequency, Shannon entropy.
 .SH COMPATIBILITY
 .sp
 Compression is done using the COW mechanism so it\(aqs incompatible with
-\fInodatacow\fP\&. Direct IO works on compressed files but will fall back to buffered
-writes and leads to recompression. Currently \fInodatasum\fP and compression don\(aqt
-work together.
+\fInodatacow\fP\&. Direct IO read works on compressed files but will fall back to
+buffered writes and leads to no compression even if force compression is set.
+Currently \fInodatasum\fP and compression don\(aqt work together.
 .sp
 The compression algorithms have been added over time so the version
 compatibility should be also considered, together with other tools that may
@@ -1886,7 +1886,7 @@ depends on the \fInodesize\fP value, for 4KiB it\(aqs 3949 bytes, for larger nod
 it\(aqs 4095 due to the system limit PATH_MAX
 .sp
 The symlink target may not be a valid path, i.e. the path name components
-can exceed the limits (NAME_MAX), there\(aqs no content validation at \fBsymlink(3)\fP
+can exceed the limits (NAME_MAX), there\(aqs no content validation at \fI\%symlink(3)\fP
 creation.
 .TP
 .B maximum number of inodes
@@ -1944,7 +1944,7 @@ old and new interfaces, with confusing names. The following list should clarify
 that:
 .INDENT 0.0
 .IP \(bu 2
-\fIattributes\fP: \fBchattr(1)\fP or \fBlsattr(1)\fP utilities (the ioctls are
+\fIattributes\fP: \fI\%chattr(1)\fP or \fI\%lsattr(1)\fP utilities (the ioctls are
 FS_IOC_GETFLAGS and FS_IOC_SETFLAGS), due to the ioctl names the attributes
 are also called flags
 .IP \(bu 2
@@ -1952,7 +1952,7 @@ are also called flags
 bits similar to the attributes but extensible and new bits will be added in
 the future (the ioctls are FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR but they
 are not related to extended attributes that are also called xattrs), there\(aqs
-no standard tool to change the bits, there\(aqs support in \fBxfs_io(8)\fP as
+no standard tool to change the bits, there\(aqs support in \fI\%xfs_io(8)\fP as
 command \fBxfs_io \-c chattr\fP
 .UNINDENT
 .SS Attributes
@@ -1986,11 +1986,11 @@ empty files.
 .UNINDENT
 .TP
 .B d
-\fIno dump\fP, makes sense with 3rd party tools like \fBdump(8)\fP, on BTRFS the
+\fIno dump\fP, makes sense with 3rd party tools like \fI\%dump(8)\fP, on BTRFS the
 attribute can be set/unset but no other special handling is done
 .TP
 .B D
-\fIsynchronous directory updates\fP, for more details search \fBopen(2)\fP for \fIO_SYNC\fP
+\fIsynchronous directory updates\fP, for more details search \fI\%open(2)\fP for \fIO_SYNC\fP
 and \fIO_DSYNC\fP
 .TP
 .B i
@@ -1999,23 +1999,23 @@ long as this attribute is set (obviously the exception is unsetting the attribut
 .TP
 .B m
 \fIno compression\fP, permanently turn off compression on the given file. Any
-compression mount options will not affect this file. (\fBchattr\fP support added in
+compression mount options will not affect this file. (\fI\%chattr(1)\fP support added in
 1.46.2)
 .sp
 When set on a directory, all newly created files will inherit this attribute.
 This attribute cannot be set with \fIc\fP at the same time.
 .TP
 .B S
-\fIsynchronous updates\fP, for more details search \fBopen(2)\fP for \fIO_SYNC\fP and
+\fIsynchronous updates\fP, for more details search \fI\%open(2)\fP for \fIO_SYNC\fP and
 \fIO_DSYNC\fP
 .UNINDENT
 .sp
 No other attributes are supported.  For the complete list please refer to the
-\fBchattr(1)\fP manual page.
+\fI\%chattr(1)\fP manual page.
 .SS XFLAGS
 .sp
 There\(aqs an overlap of letters assigned to the bits with the attributes, this list
-refers to what \fBxfs_io(8)\fP provides:
+refers to what \fI\%xfs_io(8)\fP provides:
 .INDENT 0.0
 .TP
 .B i
@@ -2757,10 +2757,23 @@ have been demonstrated (\fIrowhammer\fP) achieving specific bits to be flipped.
 While these were targeted, this shows that a series of reads or writes can
 affect unrelated parts of memory.
 .sp
+Block group profiles with redundancy (like RAID1) will not protect against
+memory errors as the blocks are first stored in memory before they are written
+to the devices from the same source.
+.sp
+A filesystem mounted read\-only will not affect the underlying block device in
+almost 100% (with highly unlikely exceptions). The exception is a tree\-log that
+needs to be replayed during mount (and before the read\-only mount takes place),
+working memory is needed for that and that can be affected by bit flips.
+There\(aqs a theoretical case where bit flip changes the filesystem status from
+read\-only to read\-write.
+.sp
 Further reading:
 .INDENT 0.0
 .IP \(bu 2
 \fI\%https://en.wikipedia.org/wiki/Row_hammer\fP
+.IP \(bu 2
+memory overclocking, XMP, potential risks
 .UNINDENT
 .sp
 What to do:
@@ -2772,6 +2785,10 @@ is under heavy load that the default memtest cannot trigger
 memory errors may appear as filesystem going read\-only due to \(dqpre write\(dq
 check, that verify meta data before they get written but fail some basic
 consistency checks
+.IP \(bu 2
+newly built systems should be tested before being put to production use,
+ideally start a IO/CPU load that will be run on such system later; namely
+systems that will utilize overclocking or special performance features
 .UNINDENT
 .SS Direct memory access (DMA)
 .sp
@@ -2827,7 +2844,7 @@ to avoid unnecessary resets and performs optimizations to maximize the storage
 media lifetime. The known techniques are deduplication (blocks with same
 fingerprint/hash are mapped to same physical block), compression or internal
 remapping and garbage collection of used memory cells. Due to the additional
-processing there are measures to verity the data e.g. by ECC codes.
+processing there are measures to verify the data e.g. by ECC codes.
 .sp
 The observations of failing SSDs show that the whole electronic fails at once
 or affects a lot of data (e.g. stored on one chip). Recovering such data
@@ -2960,13 +2977,13 @@ and replacing the card could be required as well.
 filesystem when it tells you.\fP
 .SH SEE ALSO
 .sp
-\fBacl(5)\fP,
+\fI\%acl(5)\fP,
 \fI\%btrfs(8)\fP,
-\fBchattr(1)\fP,
-\fBfstrim(8)\fP,
-\fBioctl(2)\fP,
+\fI\%chattr(1)\fP,
+\fI\%fstrim(8)\fP,
+\fI\%ioctl(2)\fP,
 \fI\%mkfs.btrfs(8)\fP,
-\fBmount(8)\fP,
-\fBswapon(8)\fP
+\fI\%mount(8)\fP,
+\fI\%swapon(8)\fP
 .\" Generated by docutils manpage writer.
 .