From c53cd490b1a491ebf1d8e30da97e7231459a4208 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 12 Jul 2017 11:49:50 -0700 Subject: kernfs: introduce kernfs_node_id inode number and generation can identify a kernfs node. We are going to export the identification by exportfs operations, so put ino and generation into a separate structure. It's convenient when later patches use the identification. Acked-by: Greg Kroah-Hartman Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- include/linux/cgroup.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 710a005c6b7a..30c68773fd1e 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -543,7 +543,7 @@ static inline bool cgroup_is_populated(struct cgroup *cgrp) /* returns ino associated with a cgroup */ static inline ino_t cgroup_ino(struct cgroup *cgrp) { - return cgrp->kn->ino; + return cgrp->kn->id.ino; } /* cft/css accessors for cftype->write() operation */ -- cgit v1.2.3-59-g8ed1b From 121508df44d074245a72eda6b067478218480a40 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 12 Jul 2017 11:49:52 -0700 Subject: cgroup: export fhandle info for a cgroup Add an API to export cgroup fhandle info. We don't export a full 'struct file_handle', there are unrequired info. Sepcifically, cgroup is always a directory, so we don't need a 'FILEID_INO32_GEN_PARENT' type fhandle, we only need export the inode number and generation number just like what generic_fh_to_dentry does. And we can avoid the overhead of getting an inode too, since kernfs_node_id (ino and generation) has all the info required. Acked-by: Tejun Heo Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- include/linux/cgroup.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 30c68773fd1e..52ef9a68ff14 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -609,6 +609,10 @@ static inline void cgroup_kthread_ready(void) current->no_cgroup_migration = 0; } +static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) +{ + return &cgrp->kn->id; +} #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -631,6 +635,10 @@ static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } static inline void cgroup_init_kthreadd(void) {} static inline void cgroup_kthread_ready(void) {} +static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) +{ + return NULL; +} static inline bool task_under_cgroup_hierarchy(struct task_struct *task, struct cgroup *ancestor) -- cgit v1.2.3-59-g8ed1b From 69fd5c391763bd94a40dd152bc72a7f230137150 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Wed, 12 Jul 2017 11:49:55 -0700 Subject: blktrace: add an option to allow displaying cgroup path By default we output cgroup id in blktrace. This adds an option to display cgroup path. Since get cgroup path is a relativly heavy operation, we don't enable it by default. with the option enabled, blktrace will output something like this: dd-1353 [007] d..2 293.015252: 8,0 /test/level D R 24 + 8 [dd] Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- fs/kernfs/mount.c | 19 +++++++++++++++++++ include/linux/cgroup.h | 6 ++++++ include/linux/kernfs.h | 2 ++ kernel/cgroup/cgroup.c | 12 ++++++++++++ kernel/trace/blktrace.c | 14 +++++++++++++- 5 files changed, 52 insertions(+), 1 deletion(-) (limited to 'include/linux/cgroup.h') diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index fa323589704f..7c452f4d83e9 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -65,6 +65,25 @@ const struct super_operations kernfs_sops = { .show_path = kernfs_sop_show_path, }; +/* + * Similar to kernfs_fh_get_inode, this one gets kernfs node from inode + * number and generation + */ +struct kernfs_node *kernfs_get_node_by_id(struct kernfs_root *root, + const union kernfs_node_id *id) +{ + struct kernfs_node *kn; + + kn = kernfs_find_and_get_node_by_ino(root, id->ino); + if (!kn) + return NULL; + if (kn->id.generation != id->generation) { + kernfs_put(kn); + return NULL; + } + return kn; +} + static struct inode *kernfs_fh_get_inode(struct super_block *sb, u64 ino, u32 generation) { diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 52ef9a68ff14..6144fe923b73 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -613,6 +613,9 @@ static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) { return &cgrp->kn->id; } + +void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, + char *buf, size_t buflen); #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -645,6 +648,9 @@ static inline bool task_under_cgroup_hierarchy(struct task_struct *task, { return true; } + +static inline void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, + char *buf, size_t buflen) {} #endif /* !CONFIG_CGROUPS */ /* diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index d149361e5875..ab25c8b6d9e3 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -358,6 +358,8 @@ struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns); void kernfs_init(void); +struct kernfs_node *kernfs_get_node_by_id(struct kernfs_root *root, + const union kernfs_node_id *id); #else /* CONFIG_KERNFS */ static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 6cefa277f39c..2aba1c519138 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4701,6 +4701,18 @@ static int __init cgroup_wq_init(void) } core_initcall(cgroup_wq_init); +void cgroup_path_from_kernfs_id(const union kernfs_node_id *id, + char *buf, size_t buflen) +{ + struct kernfs_node *kn; + + kn = kernfs_get_node_by_id(cgrp_dfl_root.kf_root, id); + if (!kn) + return; + kernfs_path(kn, buf, buflen); + kernfs_put(kn); +} + /* * proc_cgroup_show() * - Print task's cgroup paths into seq_file, one line for each hierarchy diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index f393d7a43695..e90974ed4532 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -48,12 +48,14 @@ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(running_trace_lock); /* Select an alternative, minimalistic output than the original one */ #define TRACE_BLK_OPT_CLASSIC 0x1 #define TRACE_BLK_OPT_CGROUP 0x2 +#define TRACE_BLK_OPT_CGNAME 0x4 static struct tracer_opt blk_tracer_opts[] = { /* Default disable the minimalistic output */ { TRACER_OPT(blk_classic, TRACE_BLK_OPT_CLASSIC) }, #ifdef CONFIG_BLK_CGROUP { TRACER_OPT(blk_cgroup, TRACE_BLK_OPT_CGROUP) }, + { TRACER_OPT(blk_cgname, TRACE_BLK_OPT_CGNAME) }, #endif { } }; @@ -1213,7 +1215,17 @@ static void blk_log_action(struct trace_iterator *iter, const char *act, if (has_cg) { const union kernfs_node_id *id = cgid_start(iter->ent); - trace_seq_printf(&iter->seq, "%3d,%-3d %x,%-x %2s %3s ", + if (blk_tracer_flags.val & TRACE_BLK_OPT_CGNAME) { + char blkcg_name_buf[NAME_MAX + 1] = "<...>"; + + cgroup_path_from_kernfs_id(id, blkcg_name_buf, + sizeof(blkcg_name_buf)); + trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ", + MAJOR(t->device), MINOR(t->device), + blkcg_name_buf, act, rwbs); + } else + trace_seq_printf(&iter->seq, + "%3d,%-3d %x,%-x %2s %3s ", MAJOR(t->device), MINOR(t->device), id->ino, id->generation, act, rwbs); } else -- cgit v1.2.3-59-g8ed1b