diff options
| -rw-r--r-- | fs/kernfs/dir.c | 42 | ||||
| -rw-r--r-- | fs/kernfs/mount.c | 7 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 20 | ||||
| -rw-r--r-- | kernel/trace/blktrace.c | 21 |
4 files changed, 64 insertions, 26 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 5dcf19d4adbc..b2d9f79c4a7c 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -532,7 +532,7 @@ void kernfs_put(struct kernfs_node *kn) kmem_cache_free(kernfs_iattrs_cache, kn->iattr); } spin_lock(&kernfs_idr_lock); - idr_remove(&root->ino_idr, kernfs_ino(kn)); + idr_remove(&root->ino_idr, (u32)kernfs_ino(kn)); spin_unlock(&kernfs_idr_lock); kmem_cache_free(kernfs_node_cache, kn); @@ -617,7 +617,7 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, unsigned flags) { struct kernfs_node *kn; - u32 gen; + u32 id_highbits; int ret; name = kstrdup_const(name, GFP_KERNEL); @@ -631,16 +631,16 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, idr_preload(GFP_KERNEL); spin_lock(&kernfs_idr_lock); ret = idr_alloc_cyclic(&root->ino_idr, kn, 1, 0, GFP_ATOMIC); - if (ret >= 0 && ret < root->last_ino) - root->next_generation++; - gen = root->next_generation; - root->last_ino = ret; + if (ret >= 0 && ret < root->last_id_lowbits) + root->id_highbits++; + id_highbits = root->id_highbits; + root->last_id_lowbits = ret; spin_unlock(&kernfs_idr_lock); idr_preload_end(); if (ret < 0) goto err_out2; - kn->id = (u64)gen << 32 | ret; + kn->id = (u64)id_highbits << 32 | ret; atomic_set(&kn->count, 1); atomic_set(&kn->active, KN_DEACTIVATED_BIAS); @@ -671,7 +671,7 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, return kn; err_out3: - idr_remove(&root->ino_idr, kernfs_ino(kn)); + idr_remove(&root->ino_idr, (u32)kernfs_ino(kn)); err_out2: kmem_cache_free(kernfs_node_cache, kn); err_out1: @@ -715,13 +715,19 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, spin_lock(&kernfs_idr_lock); - kn = idr_find(&root->ino_idr, ino); + kn = idr_find(&root->ino_idr, (u32)ino); if (!kn) goto err_unlock; - /* 0 matches all generations */ - if (unlikely(gen && kernfs_gen(kn) != gen)) - goto err_unlock; + if (sizeof(ino_t) >= sizeof(u64)) { + /* we looked up with the low 32bits, compare the whole */ + if (kernfs_ino(kn) != ino) + goto err_unlock; + } else { + /* 0 matches all generations */ + if (unlikely(gen && kernfs_gen(kn) != gen)) + goto err_unlock; + } /* * ACTIVATED is protected with kernfs_mutex but it was clear when @@ -949,7 +955,17 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops, idr_init(&root->ino_idr); INIT_LIST_HEAD(&root->supers); - root->next_generation = 1; + + /* + * On 64bit ino setups, id is ino. On 32bit, low 32bits are ino. + * High bits generation. The starting value for both ino and + * genenration is 1. Initialize upper 32bit allocation + * accordingly. + */ + if (sizeof(ino_t) >= sizeof(u64)) + root->id_highbits = 0; + else + root->id_highbits = 1; kn = __kernfs_new_node(root, NULL, "", S_IFDIR | S_IRUGO | S_IXUGO, GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 37a1e5df117a..4d31503abaee 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -87,9 +87,10 @@ static struct dentry *__kernfs_fh_to_dentry(struct super_block *sb, case FILEID_INO32_GEN: case FILEID_INO32_GEN_PARENT: /* - * blk_log_action() exposes (ino,gen) pair without type and - * userland can call us with generic fid constructed from - * them. Combine it back to ID. See blk_log_action(). + * blk_log_action() exposes "LOW32,HIGH32" pair without + * type and userland can call us with generic fid + * constructed from them. Combine it back to ID. See + * blk_log_action(). */ id = ((u64)fid->i32.gen << 32) | fid->i32.ino; break; diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 38267cc9420c..dded2e5a9f42 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -141,8 +141,8 @@ struct kernfs_node { void *priv; /* - * 64bit unique ID. Lower 32bits carry the inode number and lower - * generation. + * 64bit unique ID. On 64bit ino setups, id is the ino. On 32bit, + * the low 32bits are ino and upper generation. */ u64 id; @@ -177,8 +177,8 @@ struct kernfs_root { /* private fields, do not use outside kernfs proper */ struct idr ino_idr; - u32 last_ino; - u32 next_generation; + u32 last_id_lowbits; + u32 id_highbits; struct kernfs_syscall_ops *syscall_ops; /* list of kernfs_super_info of this root, protected by kernfs_mutex */ @@ -284,12 +284,20 @@ static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) static inline ino_t kernfs_id_ino(u64 id) { - return (u32)id; + /* id is ino if ino_t is 64bit; otherwise, low 32bits */ + if (sizeof(ino_t) >= sizeof(u64)) + return id; + else + return (u32)id; } static inline u32 kernfs_id_gen(u64 id) { - return id >> 32; + /* gen is fixed at 1 if ino_t is 64bit; otherwise, high 32bits */ + if (sizeof(ino_t) >= sizeof(u64)) + return 1; + else + return id >> 32; } static inline ino_t kernfs_ino(struct kernfs_node *kn) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index a986d2e74ca2..a7dac5b63f3f 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1261,12 +1261,25 @@ static void blk_log_action(struct trace_iterator *iter, const char *act, trace_seq_printf(&iter->seq, "%3d,%-3d %s %2s %3s ", MAJOR(t->device), MINOR(t->device), blkcg_name_buf, act, rwbs); - } else + } else { + /* + * The cgid portion used to be "INO,GEN". Userland + * builds a FILEID_INO32_GEN fid out of them and + * opens the cgroup using open_by_handle_at(2). + * While 32bit ino setups are still the same, 64bit + * ones now use the 64bit ino as the whole ID and + * no longer use generation. + * + * Regarldess of the content, always output + * "LOW32,HIGH32" so that FILEID_INO32_GEN fid can + * be mapped back to @id on both 64 and 32bit ino + * setups. See __kernfs_fh_to_dentry(). + */ trace_seq_printf(&iter->seq, - "%3d,%-3d %lx,%-x %2s %3s ", + "%3d,%-3d %llx,%-llx %2s %3s ", MAJOR(t->device), MINOR(t->device), - kernfs_id_ino(id), kernfs_id_gen(id), - act, rwbs); + id & U32_MAX, id >> 32, act, rwbs); + } } else trace_seq_printf(&iter->seq, "%3d,%-3d %2s %3s ", MAJOR(t->device), MINOR(t->device), act, rwbs); |