From e6ec453bd0f03a60a80f00f95ae2eaa260faa3c2 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Fri, 22 Sep 2023 12:12:14 +0800 Subject: autofs: convert autofs to use the new mount api Convert the autofs filesystem to use the mount API. The conversion patch was originally written by David Howells. I have taken that patch and broken it into several patches in an effort to make the change easier to review. Signed-off-by: Ian Kent Reviewed-by: Bill O'Donnell Message-Id: <20230922041215.13675-8-raven@themaw.net> Signed-off-by: Christian Brauner --- fs/autofs/autofs_i.h | 5 +- fs/autofs/init.c | 9 +- fs/autofs/inode.c | 265 +++++++++++++++++++++++++++++---------------------- 3 files changed, 155 insertions(+), 124 deletions(-) (limited to 'fs/autofs') diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h index c24d32be7937..244f18cdf23c 100644 --- a/fs/autofs/autofs_i.h +++ b/fs/autofs/autofs_i.h @@ -25,6 +25,8 @@ #include #include #include +#include +#include /* This is the range of ioctl() numbers we claim as ours */ #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY @@ -205,7 +207,8 @@ static inline void managed_dentry_clear_managed(struct dentry *dentry) /* Initializing function */ -int autofs_fill_super(struct super_block *, void *, int); +extern const struct fs_parameter_spec autofs_param_specs[]; +int autofs_init_fs_context(struct fs_context *fc); struct autofs_info *autofs_new_ino(struct autofs_sb_info *); void autofs_clean_ino(struct autofs_info *); diff --git a/fs/autofs/init.c b/fs/autofs/init.c index d3f55e874338..b5e4dfa04ed0 100644 --- a/fs/autofs/init.c +++ b/fs/autofs/init.c @@ -7,16 +7,11 @@ #include #include "autofs_i.h" -static struct dentry *autofs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) -{ - return mount_nodev(fs_type, flags, data, autofs_fill_super); -} - struct file_system_type autofs_fs_type = { .owner = THIS_MODULE, .name = "autofs", - .mount = autofs_mount, + .init_fs_context = autofs_init_fs_context, + .parameters = autofs_param_specs, .kill_sb = autofs_kill_sb, }; MODULE_ALIAS_FS("autofs"); diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c index e2026e063d8c..0477bce7d277 100644 --- a/fs/autofs/inode.c +++ b/fs/autofs/inode.c @@ -6,7 +6,6 @@ #include #include -#include #include "autofs_i.h" @@ -111,7 +110,6 @@ static const struct super_operations autofs_sops = { }; enum { - Opt_err, Opt_direct, Opt_fd, Opt_gid, @@ -125,100 +123,106 @@ enum { Opt_uid, }; -static const match_table_t tokens = { - {Opt_fd, "fd=%u"}, - {Opt_uid, "uid=%u"}, - {Opt_gid, "gid=%u"}, - {Opt_pgrp, "pgrp=%u"}, - {Opt_minproto, "minproto=%u"}, - {Opt_maxproto, "maxproto=%u"}, - {Opt_indirect, "indirect"}, - {Opt_direct, "direct"}, - {Opt_offset, "offset"}, - {Opt_strictexpire, "strictexpire"}, - {Opt_ignore, "ignore"}, - {Opt_err, NULL} +const struct fs_parameter_spec autofs_param_specs[] = { + fsparam_flag ("direct", Opt_direct), + fsparam_fd ("fd", Opt_fd), + fsparam_u32 ("gid", Opt_gid), + fsparam_flag ("ignore", Opt_ignore), + fsparam_flag ("indirect", Opt_indirect), + fsparam_u32 ("maxproto", Opt_maxproto), + fsparam_u32 ("minproto", Opt_minproto), + fsparam_flag ("offset", Opt_offset), + fsparam_u32 ("pgrp", Opt_pgrp), + fsparam_flag ("strictexpire", Opt_strictexpire), + fsparam_u32 ("uid", Opt_uid), + {} }; -static int autofs_parse_fd(struct autofs_sb_info *sbi, int fd) +struct autofs_fs_context { + kuid_t uid; + kgid_t gid; + int pgrp; + bool pgrp_set; +}; + +/* + * Open the fd. We do it here rather than in get_tree so that it's done in the + * context of the system call that passed the data and not the one that + * triggered the superblock creation, lest the fd gets reassigned. + */ +static int autofs_parse_fd(struct fs_context *fc, struct autofs_sb_info *sbi, + struct fs_parameter *param, + struct fs_parse_result *result) { struct file *pipe; int ret; - pipe = fget(fd); + if (param->type == fs_value_is_file) { + /* came through the new api */ + pipe = param->file; + param->file = NULL; + } else { + pipe = fget(result->uint_32); + } if (!pipe) { - pr_err("could not open pipe file descriptor\n"); + errorf(fc, "could not open pipe file descriptor"); return -EBADF; } ret = autofs_check_pipe(pipe); if (ret < 0) { - pr_err("Invalid/unusable pipe\n"); - fput(pipe); + errorf(fc, "Invalid/unusable pipe"); + if (param->type != fs_value_is_file) + fput(pipe); return -EBADF; } if (sbi->pipe) fput(sbi->pipe); - sbi->pipefd = fd; + sbi->pipefd = result->uint_32; sbi->pipe = pipe; return 0; } -static int autofs_parse_param(char *optstr, struct inode *root, - int *pgrp, bool *pgrp_set, - struct autofs_sb_info *sbi) +static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param) { - substring_t args[MAX_OPT_ARGS]; - int option; - int pipefd = -1; + struct autofs_fs_context *ctx = fc->fs_private; + struct autofs_sb_info *sbi = fc->s_fs_info; + struct fs_parse_result result; kuid_t uid; kgid_t gid; - int token; - int ret; + int opt; + + opt = fs_parse(fc, autofs_param_specs, param, &result); + if (opt < 0) + return opt; - token = match_token(optstr, tokens, args); - switch (token) { + switch (opt) { case Opt_fd: - if (match_int(args, &pipefd)) - return 1; - ret = autofs_parse_fd(sbi, pipefd); - if (ret) - return 1; - break; + return autofs_parse_fd(fc, sbi, param, &result); case Opt_uid: - if (match_int(args, &option)) - return 1; - uid = make_kuid(current_user_ns(), option); + uid = make_kuid(current_user_ns(), result.uint_32); if (!uid_valid(uid)) - return 1; - root->i_uid = uid; + return invalfc(fc, "Invalid uid"); + ctx->uid = uid; break; case Opt_gid: - if (match_int(args, &option)) - return 1; - gid = make_kgid(current_user_ns(), option); + gid = make_kgid(current_user_ns(), result.uint_32); if (!gid_valid(gid)) - return 1; - root->i_gid = gid; + return invalfc(fc, "Invalid gid"); + ctx->gid = gid; break; case Opt_pgrp: - if (match_int(args, &option)) - return 1; - *pgrp = option; - *pgrp_set = true; + ctx->pgrp = result.uint_32; + ctx->pgrp_set = true; break; case Opt_minproto: - if (match_int(args, &option)) - return 1; - sbi->min_proto = option; + sbi->min_proto = result.uint_32; break; case Opt_maxproto: - if (match_int(args, &option)) - return 1; - sbi->max_proto = option; + sbi->max_proto = result.uint_32; break; case Opt_indirect: set_autofs_type_indirect(&sbi->type); @@ -239,29 +243,6 @@ static int autofs_parse_param(char *optstr, struct inode *root, return 0; } -static int parse_options(char *options, - struct inode *root, int *pgrp, bool *pgrp_set, - struct autofs_sb_info *sbi) -{ - char *p; - - root->i_uid = current_uid(); - root->i_gid = current_gid(); - - if (!options) - return 1; - - while ((p = strsep(&options, ",")) != NULL) { - if (!*p) - continue; - - if (autofs_parse_param(p, root, pgrp, pgrp_set, sbi)) - return 1; - } - - return (sbi->pipefd < 0); -} - static struct autofs_sb_info *autofs_alloc_sbi(void) { struct autofs_sb_info *sbi; @@ -287,12 +268,14 @@ static struct autofs_sb_info *autofs_alloc_sbi(void) return sbi; } -static int autofs_validate_protocol(struct autofs_sb_info *sbi) +static int autofs_validate_protocol(struct fs_context *fc) { + struct autofs_sb_info *sbi = fc->s_fs_info; + /* Test versions first */ if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { - pr_err("kernel does not match daemon version " + errorf(fc, "kernel does not match daemon version " "daemon (%d, %d) kernel (%d, %d)\n", sbi->min_proto, sbi->max_proto, AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); @@ -309,24 +292,18 @@ static int autofs_validate_protocol(struct autofs_sb_info *sbi) return 0; } -int autofs_fill_super(struct super_block *s, void *data, int silent) +static int autofs_fill_super(struct super_block *s, struct fs_context *fc) { + struct autofs_fs_context *ctx = fc->fs_private; + struct autofs_sb_info *sbi = s->s_fs_info; struct inode *root_inode; struct dentry *root; - struct autofs_sb_info *sbi; struct autofs_info *ino; - int pgrp = 0; - bool pgrp_set = false; - int ret = -EINVAL; - - sbi = autofs_alloc_sbi(); - if (!sbi) - return -ENOMEM; + int ret = -ENOMEM; pr_debug("starting up, sbi = %p\n", sbi); sbi->sb = s; - s->s_fs_info = sbi; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = AUTOFS_SUPER_MAGIC; @@ -338,33 +315,24 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) * Get the root inode and dentry, but defer checking for errors. */ ino = autofs_new_ino(sbi); - if (!ino) { - ret = -ENOMEM; - goto fail_free; - } + if (!ino) + goto fail; + root_inode = autofs_get_inode(s, S_IFDIR | 0755); + root_inode->i_uid = ctx->uid; + root_inode->i_gid = ctx->gid; + root = d_make_root(root_inode); - if (!root) { - ret = -ENOMEM; + if (!root) goto fail_ino; - } root->d_fsdata = ino; - /* Can this call block? */ - if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) { - pr_err("called with bogus options\n"); - goto fail_dput; - } - - if (autofs_validate_protocol(sbi)) - goto fail_dput; - - if (pgrp_set) { - sbi->oz_pgrp = find_get_pid(pgrp); + if (ctx->pgrp_set) { + sbi->oz_pgrp = find_get_pid(ctx->pgrp); if (!sbi->oz_pgrp) { - pr_err("could not find process group %d\n", - pgrp); + ret = invalf(fc, "Could not find process group %d", + ctx->pgrp); goto fail_dput; } } else { @@ -393,15 +361,80 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) */ fail_dput: dput(root); - goto fail_free; + goto fail; fail_ino: autofs_free_ino(ino); -fail_free: - kfree(sbi); - s->s_fs_info = NULL; +fail: return ret; } +/* + * Validate the parameters and then request a superblock. + */ +static int autofs_get_tree(struct fs_context *fc) +{ + struct autofs_sb_info *sbi = fc->s_fs_info; + int ret; + + ret = autofs_validate_protocol(fc); + if (ret) + return ret; + + if (sbi->pipefd < 0) + return invalf(fc, "No control pipe specified"); + + return get_tree_nodev(fc, autofs_fill_super); +} + +static void autofs_free_fc(struct fs_context *fc) +{ + struct autofs_fs_context *ctx = fc->fs_private; + struct autofs_sb_info *sbi = fc->s_fs_info; + + if (sbi) { + if (sbi->pipe) + fput(sbi->pipe); + kfree(sbi); + } + kfree(ctx); +} + +static const struct fs_context_operations autofs_context_ops = { + .free = autofs_free_fc, + .parse_param = autofs_parse_param, + .get_tree = autofs_get_tree, +}; + +/* + * Set up the filesystem mount context. + */ +int autofs_init_fs_context(struct fs_context *fc) +{ + struct autofs_fs_context *ctx; + struct autofs_sb_info *sbi; + + ctx = kzalloc(sizeof(struct autofs_fs_context), GFP_KERNEL); + if (!ctx) + goto nomem; + + ctx->uid = current_uid(); + ctx->gid = current_gid(); + + sbi = autofs_alloc_sbi(); + if (!sbi) + goto nomem_ctx; + + fc->fs_private = ctx; + fc->s_fs_info = sbi; + fc->ops = &autofs_context_ops; + return 0; + +nomem_ctx: + kfree(ctx); +nomem: + return -ENOMEM; +} + struct inode *autofs_get_inode(struct super_block *sb, umode_t mode) { struct inode *inode = new_inode(sb); -- cgit