Yafang Shao e6957c99dc vfs: Add a sysctl for automated deletion of dentry ... Commit 681ce86235 ("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 4a4be1ad3a ("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 681ce86235, 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>		2024-10-22 11:16:57 +02:00
..
abi.rst	docs: admin-guide: sysctl: avoid using ReST :doc:foo markup	2021-06-17 13:24:36 -06:00
fs.rst	vfs: Add a sysctl for automated deletion of dentry	2024-10-22 11:16:57 +02:00
index.rst
kernel.rst	parisc: Add support for CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN	2024-07-24 02:04:05 +02:00
net.rst	ARC: Add eBPF JIT support	2024-05-12 16:51:36 -07:00
sunrpc.rst
user.rst	time/namespace: Add max_time_namespaces ucount	2020-04-07 12:37:21 +02:00
vm.rst	docs: mm: add enable_soft_offline sysctl	2024-07-04 18:06:00 -07:00