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2025-03-31fuse: add default_request_timeout and max_request_timeout sysctlsJoanne Koong
Introduce two new sysctls, "default_request_timeout" and "max_request_timeout". These control how long (in seconds) a server can take to reply to a request. If the server does not reply by the timeout, then the connection will be aborted. The upper bound on these sysctl values is 65535. "default_request_timeout" sets the default timeout if no timeout is specified by the fuse server on mount. 0 (default) indicates no default timeout should be enforced. If the server did specify a timeout, then default_request_timeout will be ignored. "max_request_timeout" sets the max amount of time the server may take to reply to a request. 0 (default) indicates no maximum timeout. If max_request_timeout is set and the fuse server attempts to set a timeout greater than max_request_timeout, the system will use max_request_timeout as the timeout. Similarly, if default_request_timeout is greater than max_request_timeout, the system will use max_request_timeout as the timeout. If the server does not request a timeout and default_request_timeout is set to 0 but max_request_timeout is set, then the timeout will be max_request_timeout. Please note that these timeouts are not 100% precise. The request may take roughly an extra FUSE_TIMEOUT_TIMER_FREQ seconds beyond the set max timeout due to how it's internally implemented. $ sysctl -a | grep fuse.default_request_timeout fs.fuse.default_request_timeout = 0 $ echo 65536 | sudo tee /proc/sys/fs/fuse/default_request_timeout tee: /proc/sys/fs/fuse/default_request_timeout: Invalid argument $ echo 65535 | sudo tee /proc/sys/fs/fuse/default_request_timeout 65535 $ sysctl -a | grep fuse.default_request_timeout fs.fuse.default_request_timeout = 65535 $ echo 0 | sudo tee /proc/sys/fs/fuse/default_request_timeout 0 $ sysctl -a | grep fuse.default_request_timeout fs.fuse.default_request_timeout = 0 [Luis Henriques: Limit the timeout to the range [FUSE_TIMEOUT_TIMER_FREQ, fuse_max_req_timeout]] Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Luis Henriques <luis@igalia.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-12-11docs: remove duplicate wordRuffalo Lavoisier
- Remove duplicate word, 'to'. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20241120043414.78811-1-RuffaloLavoisier@gmail.com
2024-11-26Merge tag 'fuse-update-6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Add page -> folio conversions (Joanne Koong, Josef Bacik) - Allow max size of fuse requests to be configurable with a sysctl (Joanne Koong) - Allow FOPEN_DIRECT_IO to take advantage of async code path (yangyun) - Fix large kernel reads (like a module load) in virtio_fs (Hou Tao) - Fix attribute inconsistency in case readdirplus (and plain lookup in corner cases) is racing with inode eviction (Zhang Tianci) - Fix a WARN_ON triggered by virtio_fs (Asahi Lina) * tag 'fuse-update-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (30 commits) virtiofs: dax: remove ->writepages() callback fuse: check attributes staleness on fuse_iget() fuse: remove pages for requests and exclusively use folios fuse: convert direct io to use folios mm/writeback: add folio_mark_dirty_lock() fuse: convert writebacks to use folios fuse: convert retrieves to use folios fuse: convert ioctls to use folios fuse: convert writes (non-writeback) to use folios fuse: convert reads to use folios fuse: convert readdir to use folios fuse: convert readlink to use folios fuse: convert cuse to use folios fuse: add support in virtio for requests using folios fuse: support folios in struct fuse_args_pages and fuse_copy_pages() fuse: convert fuse_notify_store to use folios fuse: convert fuse_retrieve to use folios fuse: use the folio based vmstat helpers fuse: convert fuse_writepage_need_send to take a folio fuse: convert fuse_do_readpage to use folios ...
2024-10-25fuse: enable dynamic configuration of fuse max pages limit (FUSE_MAX_MAX_PAGES)Joanne Koong
Introduce the capability to dynamically configure the max pages limit (FUSE_MAX_MAX_PAGES) through a sysctl. This allows system administrators to dynamically set the maximum number of pages that can be used for servicing requests in fuse. Previously, this is gated by FUSE_MAX_MAX_PAGES which is statically set to 256 pages. One result of this is that the buffer size for a write request is limited to 1 MiB on a 4k-page system. The default value for this sysctl is the original limit (256 pages). $ sysctl -a | grep max_pages_limit fs.fuse.max_pages_limit = 256 $ sysctl -n fs.fuse.max_pages_limit 256 $ echo 1024 | sudo tee /proc/sys/fs/fuse/max_pages_limit 1024 $ sysctl -n fs.fuse.max_pages_limit 1024 $ echo 65536 | sudo tee /proc/sys/fs/fuse/max_pages_limit tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument $ echo 0 | sudo tee /proc/sys/fs/fuse/max_pages_limit tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument $ echo 65535 | sudo tee /proc/sys/fs/fuse/max_pages_limit 65535 $ sysctl -n fs.fuse.max_pages_limit 65535 Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2024-10-22vfs: Add a sysctl for automated deletion of dentryYafang Shao
Commit 681ce8623567 ("vfs: Delete the associated dentry when deleting a file") introduced an unconditional deletion of the associated dentry when a file is removed. However, this led to performance regressions in specific benchmarks, such as ilebench.sum_operations/s [0], prompting a revert in commit 4a4be1ad3a6e ("Revert "vfs: Delete the associated dentry when deleting a file""). This patch seeks to reintroduce the concept conditionally, where the associated dentry is deleted only when the user explicitly opts for it during file removal. A new sysctl fs.automated_deletion_of_dentry is added for this purpose. Its default value is set to 0. There are practical use cases for this proactive dentry reclamation. Besides the Elasticsearch use case mentioned in commit 681ce8623567, additional examples have surfaced in our production environment. For instance, in video rendering services that continuously generate temporary files, upload them to persistent storage servers, and then delete them, a large number of negative dentries—serving no useful purpose—accumulate. Users in such cases would benefit from proactively reclaiming these negative dentries. Link: https://lore.kernel.org/linux-fsdevel/202405291318.4dfbb352-oliver.sang@intel.com [0] Link: https://lore.kernel.org/all/20240912-programm-umgibt-a1145fa73bb6@brauner/ Suggested-by: Christian Brauner <brauner@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20240929122831.92515-1-laoar.shao@gmail.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Mateusz Guzik <mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-03docs: admin-guide: sysctl: fix details of struct dentry_stat_tRandy Dunlap
Commit c8c0c239d5ab moved struct dentry_stat_t to fs/dcache.c but did not update its location in Documentation, so update that now. Also change each struct member from int to long as done in commit 3942c07ccf98. Fixes: c8c0c239d5ab ("fs: move dcache sysctls to its own file") Fixes: 3942c07ccf98 ("fs: bump inode and dentry counters to long") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: linux-fsdevel@vger.kernel.org Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Glauber Costa <glommer@openvz.org> Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230923195144.26043-1-rdunlap@infradead.org
2022-10-19docs: sysctl/fs: re-order, prettifyStephen Kitt
This brings the text markup in line with sysctl/abi and sysctl/kernel: * the entries are ordered alphabetically * the table of contents is automatically generated * markup is used as appropriate for constants etc. The content isn't fully up-to-date but the obsolete entries are gone, so remove the kernel version mention. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20220930102937.135841-6-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-10-19docs: sysctl/fs: remove references to super-max/-nrStephen Kitt
These were removed in 2.4.7.8. Remove references to super-max and super-nr in the sysctl documentation. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20220930102937.135841-5-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-10-19docs: sysctl/fs: merge the aio sectionsStephen Kitt
There are two sections documenting aio-nr and aio-max-nr, merge them. I kept the second explanation of aio-nr, which seems clearer to me, along with the effects of the values from the first section. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20220930102937.135841-4-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-10-19docs: sysctl/fs: remove references to dquot-max/-nrStephen Kitt
dquot-max was removed in 2.4.10.5; dquot-nr was replaced with dqstats in 2.5.18 which is now /proc/sys/fs/quota. Remove references to dquot-max and dquot-nr in the sysctl documentation. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20220930102937.135841-3-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-10-19docs: sysctl/fs: remove references to inode-maxStephen Kitt
inode-max was removed in 2.3.20pre1, remove references to it in the sysctl documentation. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20220930102937.135841-2-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-28Update Documentation/admin-guide/sysctl/fs.rstEric Curtin
max_user_watches for epoll should say 1/25, rather than 1/32 Signed-off-by: Eric Curtin <ericcurtin17@gmail.com> Link: https://lore.kernel.org/r/20210120132648.19046-1-ericcurtin17@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Replace HTTP links with HTTPS ones: Documentation/admin-guideAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200627072935.62652-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-15docs: admin-guide: move sysctl directory to itMauro Carvalho Chehab
The stuff under sysctl describes /sys interface from userspace point of view. So, add it to the admin-guide and remove the :orphan: from its index file. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>