| Message ID | cover.1688393619.git.nabijaczleweli@nabijaczleweli.xyz (mailing list archive) |
|---|---|
| Headers | show |
| Series | fanotify accounting for fs/splice.c | expand |
On Mon, 03 Jul 2023 16:42:05 +0200, Ahelenia Ziemiańska wrote: > Previously: https://lore.kernel.org/linux-fsdevel/jbyihkyk5dtaohdwjyivambb2gffyjs3dodpofafnkkunxq7bu@jngkdxx65pux/t/#u > > In short: > * most read/write APIs generate ACCESS/MODIFY for the read/written file(s) > * except the [vm]splice/tee family > (actually, since 6.4, splice itself /does/ generate events but only > for the non-pipes being spliced from/to; this commit is Fixes:ed) > * userspace that registers (i|fa)notify on pipes usually relies on it > actually working (coreutils tail -f is the primo example) > * it's sub-optimal when someone with a magic syscall can fill up a > pipe simultaneously ensuring it will never get serviced > > [...] Fixed the missing single-line-{} after multi-line-{} style problem that Amir mentioned. --- Applied to the vfs.misc branch of the vfs/vfs.git tree. Patches in the vfs.misc branch should appear in linux-next soon. Please report any outstanding bugs that were missed during review in a new review to the original patch series allowing us to drop it. It's encouraged to provide Acked-bys and Reviewed-bys even though the patch has now been applied. If possible patch trailers will be updated. Note that commit hashes shown below are subject to change due to rebase, trailer updates or similar. If in doubt, please check the listed branch. tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git branch: vfs.misc [1/3] splice: always fsnotify_access(in), fsnotify_modify(out) on success https://git.kernel.org/vfs/vfs/c/cade9d70ce70 [2/3] splice: fsnotify_access(fd)/fsnotify_modify(fd) in vmsplice https://git.kernel.org/vfs/vfs/c/6aa55b7b85b5 [3/3] splice: fsnotify_access(in), fsnotify_modify(out) on success in tee https://git.kernel.org/vfs/vfs/c/6e7556086b19
Previously: https://lore.kernel.org/linux-fsdevel/jbyihkyk5dtaohdwjyivambb2gffyjs3dodpofafnkkunxq7bu@jngkdxx65pux/t/#u In short: * most read/write APIs generate ACCESS/MODIFY for the read/written file(s) * except the [vm]splice/tee family (actually, since 6.4, splice itself /does/ generate events but only for the non-pipes being spliced from/to; this commit is Fixes:ed) * userspace that registers (i|fa)notify on pipes usually relies on it actually working (coreutils tail -f is the primo example) * it's sub-optimal when someone with a magic syscall can fill up a pipe simultaneously ensuring it will never get serviced Thus: actually generate ACCESS/MODIFY for all the [vm]spliced/teed-from/to files. LTP tests are staged in https://git.sr.ht/~nabijaczleweli/ltp/commit/v4 ("inotify13: new test for fs/splice.c functions vs pipes vs inotify"), validating that one A and/or one M event per [vm]splice(), tee(), and sendfile() is generated ‒ without this patchset, this only holds for sendfile(). Amir has identified a potential performance impact caused by correctly generating events, and has prepared patches at https://github.com/amir73il/linux/commits/fsnotify_pipe that optimise the most common cases more aggressively. Please review, and please consider taking these through the vfs tree for 6.6. Thanks, Ahelenia Ziemiańska (3): splice: always fsnotify_access(in), fsnotify_modify(out) on success splice: fsnotify_access(fd)/fsnotify_modify(fd) in vmsplice splice: fsnotify_access(in), fsnotify_modify(out) on success in tee fs/splice.c | 43 +++++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 18 deletions(-)