From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- Documentation/admin-guide/index.rst | 192 ++++++++++++++++++++++++++++++++++++ 1 file changed, 192 insertions(+) create mode 100644 Documentation/admin-guide/index.rst (limited to 'Documentation/admin-guide/index.rst') diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst new file mode 100644 index 000000000..cd28dfe91 --- /dev/null +++ b/Documentation/admin-guide/index.rst @@ -0,0 +1,192 @@ +================================================= +The Linux kernel user's and administrator's guide +================================================= + +The following is a collection of user-oriented documents that have been +added to the kernel over time. There is, as yet, little overall order or +organization here — this material was not written to be a single, coherent +document! With luck things will improve quickly over time. + +General guides to kernel administration +--------------------------------------- + +This initial section contains overall information, including the README +file describing the kernel as a whole, documentation on kernel parameters, +etc. + +.. toctree:: + :maxdepth: 1 + + README + devices + + features + +A big part of the kernel's administrative interface is the /proc and sysfs +virtual filesystems; these documents describe how to interact with tem + +.. toctree:: + :maxdepth: 1 + + sysfs-rules + sysctl/index + cputopology + abi + +Security-related documentation: + +.. toctree:: + :maxdepth: 1 + + hw-vuln/index + LSM/index + perf-security + +Booting the kernel +------------------ + +.. toctree:: + :maxdepth: 1 + + bootconfig + kernel-parameters + efi-stub + initrd + + +Tracking down and identifying problems +-------------------------------------- + +Here is a set of documents aimed at users who are trying to track down +problems and bugs in particular. + +.. toctree:: + :maxdepth: 1 + + reporting-issues + reporting-regressions + quickly-build-trimmed-linux + verify-bugs-and-bisect-regressions + bug-hunting + bug-bisect + tainted-kernels + ramoops + dynamic-debug-howto + init + kdump/index + perf/index + pstore-blk + clearing-warn-once + kernel-per-CPU-kthreads + lockup-watchdogs + RAS/index + sysrq + + +Core-kernel subsystems +---------------------- + +These documents describe core-kernel administration interfaces that are +likely to be of interest on almost any system. + +.. toctree:: + :maxdepth: 1 + + cgroup-v2 + cgroup-v1/index + cpu-isolation + cpu-load + mm/index + module-signing + namespaces/index + numastat + pm/index + syscall-user-dispatch + +Support for non-native binary formats. Note that some of these +documents are ... old ... + +.. toctree:: + :maxdepth: 1 + + binfmt-misc + java + mono + + +Block-layer and filesystem administration +----------------------------------------- + +.. toctree:: + :maxdepth: 1 + + bcache + binderfs + blockdev/index + cifs/index + device-mapper/index + ext4 + filesystem-monitoring + nfs/index + iostats + jfs + md + ufs + xfs + +Device-specific guides +---------------------- + +How to configure your hardware within your Linux system. + +.. toctree:: + :maxdepth: 1 + + acpi/index + aoe/index + auxdisplay/index + braille-console + btmrvl + dell_rbu + edid + gpio/index + hw_random + laptops/index + lcd-panel-cgram + media/index + nvme-multipath + parport + pnp + rapidio + rtc + serial-console + svga + thermal/index + thunderbolt + vga-softcursor + video-output + +Workload analysis +----------------- + +This is the beginning of a section with information of interest to +application developers and system integrators doing analysis of the +Linux kernel for safety critical applications. Documents supporting +analysis of kernel interactions with applications, and key kernel +subsystems expectations will be found here. + +.. toctree:: + :maxdepth: 1 + + workload-tracing + +Everything else +--------------- + +A few hard-to-categorize and generally obsolete documents. + +.. toctree:: + :maxdepth: 1 + + ldm + unicode -- cgit v1.3.1