diff options
Diffstat (limited to 'fs/kernfs/mount.c')
| -rw-r--r-- | fs/kernfs/mount.c | 102 |
1 files changed, 58 insertions, 44 deletions
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 6c12fac2c287..4d31503abaee 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -53,63 +53,85 @@ 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) +static int kernfs_encode_fh(struct inode *inode, __u32 *fh, int *max_len, + struct inode *parent) { - struct kernfs_node *kn; + struct kernfs_node *kn = inode->i_private; - 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; + if (*max_len < 2) { + *max_len = 2; + return FILEID_INVALID; } - return kn; + + *max_len = 2; + *(u64 *)fh = kn->id; + return FILEID_KERNFS; } -static struct inode *kernfs_fh_get_inode(struct super_block *sb, - u64 ino, u32 generation) +static struct dentry *__kernfs_fh_to_dentry(struct super_block *sb, + struct fid *fid, int fh_len, + int fh_type, bool get_parent) { struct kernfs_super_info *info = kernfs_info(sb); - struct inode *inode; struct kernfs_node *kn; + struct inode *inode; + u64 id; - if (ino == 0) - return ERR_PTR(-ESTALE); + if (fh_len < 2) + return NULL; + + switch (fh_type) { + case FILEID_KERNFS: + id = *(u64 *)fid; + break; + case FILEID_INO32_GEN: + case FILEID_INO32_GEN_PARENT: + /* + * 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; + default: + return NULL; + } - kn = kernfs_find_and_get_node_by_ino(info->root, ino); + kn = kernfs_find_and_get_node_by_id(info->root, id); if (!kn) return ERR_PTR(-ESTALE); + + if (get_parent) { + struct kernfs_node *parent; + + parent = kernfs_get_parent(kn); + kernfs_put(kn); + kn = parent; + if (!kn) + return ERR_PTR(-ESTALE); + } + inode = kernfs_get_inode(sb, kn); kernfs_put(kn); if (!inode) return ERR_PTR(-ESTALE); - if (generation && inode->i_generation != generation) { - /* we didn't find the right inode.. */ - iput(inode); - return ERR_PTR(-ESTALE); - } - return inode; + return d_obtain_alias(inode); } -static struct dentry *kernfs_fh_to_dentry(struct super_block *sb, struct fid *fid, - int fh_len, int fh_type) +static struct dentry *kernfs_fh_to_dentry(struct super_block *sb, + struct fid *fid, int fh_len, + int fh_type) { - return generic_fh_to_dentry(sb, fid, fh_len, fh_type, - kernfs_fh_get_inode); + return __kernfs_fh_to_dentry(sb, fid, fh_len, fh_type, false); } -static struct dentry *kernfs_fh_to_parent(struct super_block *sb, struct fid *fid, - int fh_len, int fh_type) +static struct dentry *kernfs_fh_to_parent(struct super_block *sb, + struct fid *fid, int fh_len, + int fh_type) { - return generic_fh_to_parent(sb, fid, fh_len, fh_type, - kernfs_fh_get_inode); + return __kernfs_fh_to_dentry(sb, fid, fh_len, fh_type, true); } static struct dentry *kernfs_get_parent_dentry(struct dentry *child) @@ -120,6 +142,7 @@ static struct dentry *kernfs_get_parent_dentry(struct dentry *child) } static const struct export_operations kernfs_export_ops = { + .encode_fh = kernfs_encode_fh, .fh_to_dentry = kernfs_fh_to_dentry, .fh_to_parent = kernfs_fh_to_parent, .get_parent = kernfs_get_parent_dentry, @@ -363,18 +386,9 @@ void kernfs_kill_sb(struct super_block *sb) void __init kernfs_init(void) { - - /* - * the slab is freed in RCU context, so kernfs_find_and_get_node_by_ino - * can access the slab lock free. This could introduce stale nodes, - * please see how kernfs_find_and_get_node_by_ino filters out stale - * nodes. - */ kernfs_node_cache = kmem_cache_create("kernfs_node_cache", sizeof(struct kernfs_node), - 0, - SLAB_PANIC | SLAB_TYPESAFE_BY_RCU, - NULL); + 0, SLAB_PANIC, NULL); /* Creates slab cache for kernfs inode attributes */ kernfs_iattrs_cache = kmem_cache_create("kernfs_iattrs_cache", |