diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index fa323589704f828c808127304af1615ca0f3f6df..7c452f4d83e937e3d66def4841c7b693b0023551 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 52ef9a68ff14c438db1256aedd97701f0094a65f..6144fe923b73b5d29285a1c74a5c42fd0912d32d 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 d149361e58756d0ea93deb014121e965a3fe8097..ab25c8b6d9e33d84bbaca9410af75339fa94385b 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 6cefa277f39c61b3ad1004bec9331bd2e883f317..2aba1c519138c2f2a61eef51dcd7ce8283cac5e9 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 f393d7a43695e4c142605354e89139d332a87594..e90974ed4532748d5f3467e445254b13f8f8545c 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