xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

inotify: Convert to using per-namespace limits

Browse Source 
This patchset converts inotify to using the newly introduced
per-userns sysctl infrastructure.

Currently the inotify instances/watches are being accounted in the
user_struct structure. This means that in setups where multiple
users in unprivileged containers map to the same underlying
real user (i.e. pointing to the same user_struct) the inotify limits
are going to be shared as well, allowing one user(or application) to exhaust
all others limits.

Fix this by switching the inotify sysctls to using the
per-namespace/per-user limits. This will allow the server admin to
set sensible global limits, which can further be tuned inside every
individual user namespace. Additionally, in order to preserve the
sysctl ABI make the existing inotify instances/watches sysctls
modify the values of the initial user namespace.

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Nikolay Borisov
2016-12-14 15:56:33 +02:00
committed by Eric W. Biederman
parent 880a38547f
commit 1cce1eea0a
7 changed files with 47 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
fs/notify/inotify/inotify.h
View File

@@ -30,3 +30,20 @@ extern int inotify_handle_event(struct fsnotify_group *group,
const unsigned char *file_name, u32 cookie);
extern const struct fsnotify_ops inotify_fsnotify_ops;
#ifdef CONFIG_INOTIFY_USER
static inline void dec_inotify_instances(struct ucounts *ucounts)
{
dec_ucount(ucounts, UCOUNT_INOTIFY_INSTANCES);
}
static inline struct ucounts *inc_inotify_watches(struct ucounts *ucounts)
{
return inc_ucount(ucounts->ns, ucounts->uid, UCOUNT_INOTIFY_WATCHES);
}
static inline void dec_inotify_watches(struct ucounts *ucounts)
{
dec_ucount(ucounts, UCOUNT_INOTIFY_WATCHES);
}
#endif