5.15-stable review patch. If anyone has any objections, please let me know.
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From: Gabriel Krisman Bertazi krisman@collabora.com
[ Upstream commit 734a1a5eccc5f7473002b0669f788e135f1f64aa ]
Pre-allocate slots for file system errors to have greater chances of succeeding, since error events can happen in GFP_NOFS context. This patch introduces a group-wide mempool of error events, shared by all FAN_FS_ERROR marks in this group.
Link: https://lore.kernel.org/r/20211025192746.66445-20-krisman@collabora.com Reviewed-by: Amir Goldstein amir73il@gmail.com Reviewed-by: Jan Kara jack@suse.cz Signed-off-by: Gabriel Krisman Bertazi krisman@collabora.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Chuck Lever chuck.lever@oracle.com --- fs/notify/fanotify/fanotify.c | 3 +++ fs/notify/fanotify/fanotify.h | 11 +++++++++++ fs/notify/fanotify/fanotify_user.c | 26 +++++++++++++++++++++++++- include/linux/fsnotify_backend.h | 2 ++ 4 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 8f152445d75c4..01d68dfc74aa2 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -819,6 +819,9 @@ static void fanotify_free_group_priv(struct fsnotify_group *group) if (group->fanotify_data.ucounts) dec_ucount(group->fanotify_data.ucounts, UCOUNT_FANOTIFY_GROUPS); + + if (mempool_initialized(&group->fanotify_data.error_events_pool)) + mempool_exit(&group->fanotify_data.error_events_pool); }
static void fanotify_free_path_event(struct fanotify_event *event) diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index c42cf8fd7d798..a577e87fac2b4 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -141,6 +141,7 @@ enum fanotify_event_type { FANOTIFY_EVENT_TYPE_PATH, FANOTIFY_EVENT_TYPE_PATH_PERM, FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */ + FANOTIFY_EVENT_TYPE_FS_ERROR, /* struct fanotify_error_event */ __FANOTIFY_EVENT_TYPE_NUM };
@@ -196,6 +197,16 @@ FANOTIFY_NE(struct fanotify_event *event) return container_of(event, struct fanotify_name_event, fae); }
+struct fanotify_error_event { + struct fanotify_event fae; +}; + +static inline struct fanotify_error_event * +FANOTIFY_EE(struct fanotify_event *event) +{ + return container_of(event, struct fanotify_error_event, fae); +} + static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event) { if (event->type == FANOTIFY_EVENT_TYPE_FID) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 8598b00f7e9c8..b3cbcb0e71c99 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -30,6 +30,7 @@ #define FANOTIFY_DEFAULT_MAX_EVENTS 16384 #define FANOTIFY_OLD_DEFAULT_MAX_MARKS 8192 #define FANOTIFY_DEFAULT_MAX_GROUPS 128 +#define FANOTIFY_DEFAULT_FEE_POOL_SIZE 32
/* * Legacy fanotify marks limits (8192) is per group and we introduced a tunable @@ -1054,6 +1055,15 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group, return ERR_PTR(ret); }
+static int fanotify_group_init_error_pool(struct fsnotify_group *group) +{ + if (mempool_initialized(&group->fanotify_data.error_events_pool)) + return 0; + + return mempool_init_kmalloc_pool(&group->fanotify_data.error_events_pool, + FANOTIFY_DEFAULT_FEE_POOL_SIZE, + sizeof(struct fanotify_error_event)); +}
static int fanotify_add_mark(struct fsnotify_group *group, fsnotify_connp_t *connp, unsigned int type, @@ -1062,6 +1072,7 @@ static int fanotify_add_mark(struct fsnotify_group *group, { struct fsnotify_mark *fsn_mark; __u32 added; + int ret = 0;
mutex_lock(&group->mark_mutex); fsn_mark = fsnotify_find_mark(connp, group); @@ -1072,13 +1083,26 @@ static int fanotify_add_mark(struct fsnotify_group *group, return PTR_ERR(fsn_mark); } } + + /* + * Error events are pre-allocated per group, only if strictly + * needed (i.e. FAN_FS_ERROR was requested). + */ + if (!(flags & FAN_MARK_IGNORED_MASK) && (mask & FAN_FS_ERROR)) { + ret = fanotify_group_init_error_pool(group); + if (ret) + goto out; + } + added = fanotify_mark_add_to_mask(fsn_mark, mask, flags); if (added & ~fsnotify_conn_mask(fsn_mark->connector)) fsnotify_recalc_mask(fsn_mark->connector); + +out: mutex_unlock(&group->mark_mutex);
fsnotify_put_mark(fsn_mark); - return 0; + return ret; }
static int fanotify_add_vfsmount_mark(struct fsnotify_group *group, diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 00dbaafbcf953..51ef2b079bfa0 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -19,6 +19,7 @@ #include <linux/atomic.h> #include <linux/user_namespace.h> #include <linux/refcount.h> +#include <linux/mempool.h>
/* * IN_* from inotfy.h lines up EXACTLY with FS_*, this is so we can easily @@ -246,6 +247,7 @@ struct fsnotify_group { int flags; /* flags from fanotify_init() */ int f_flags; /* event_f_flags from fanotify_init() */ struct ucounts *ucounts; + mempool_t error_events_pool; } fanotify_data; #endif /* CONFIG_FANOTIFY */ };