1b4d0d230SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
29bc61ab1SDavid Howells /* Provide a way to create a superblock configuration context within the kernel
39bc61ab1SDavid Howells * that allows a superblock to be set up prior to mounting.
49bc61ab1SDavid Howells *
59bc61ab1SDavid Howells * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
69bc61ab1SDavid Howells * Written by David Howells (dhowells@redhat.com)
79bc61ab1SDavid Howells */
89bc61ab1SDavid Howells
99bc61ab1SDavid Howells #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10007ec26cSDavid Howells #include <linux/module.h>
119bc61ab1SDavid Howells #include <linux/fs_context.h>
123e1aeb00SDavid Howells #include <linux/fs_parser.h>
139bc61ab1SDavid Howells #include <linux/fs.h>
149bc61ab1SDavid Howells #include <linux/mount.h>
159bc61ab1SDavid Howells #include <linux/nsproxy.h>
169bc61ab1SDavid Howells #include <linux/slab.h>
179bc61ab1SDavid Howells #include <linux/magic.h>
189bc61ab1SDavid Howells #include <linux/security.h>
199bc61ab1SDavid Howells #include <linux/mnt_namespace.h>
209bc61ab1SDavid Howells #include <linux/pid_namespace.h>
219bc61ab1SDavid Howells #include <linux/user_namespace.h>
229bc61ab1SDavid Howells #include <net/net_namespace.h>
23007ec26cSDavid Howells #include <asm/sections.h>
249bc61ab1SDavid Howells #include "mount.h"
259bc61ab1SDavid Howells #include "internal.h"
269bc61ab1SDavid Howells
273e1aeb00SDavid Howells enum legacy_fs_param {
283e1aeb00SDavid Howells LEGACY_FS_UNSET_PARAMS,
293e1aeb00SDavid Howells LEGACY_FS_MONOLITHIC_PARAMS,
303e1aeb00SDavid Howells LEGACY_FS_INDIVIDUAL_PARAMS,
313e1aeb00SDavid Howells };
323e1aeb00SDavid Howells
339bc61ab1SDavid Howells struct legacy_fs_context {
349bc61ab1SDavid Howells char *legacy_data; /* Data page for legacy filesystems */
359bc61ab1SDavid Howells size_t data_size;
363e1aeb00SDavid Howells enum legacy_fs_param param_type;
379bc61ab1SDavid Howells };
389bc61ab1SDavid Howells
399bc61ab1SDavid Howells static int legacy_init_fs_context(struct fs_context *fc);
409bc61ab1SDavid Howells
413e1aeb00SDavid Howells static const struct constant_table common_set_sb_flag[] = {
423e1aeb00SDavid Howells { "dirsync", SB_DIRSYNC },
433e1aeb00SDavid Howells { "lazytime", SB_LAZYTIME },
443e1aeb00SDavid Howells { "mand", SB_MANDLOCK },
453e1aeb00SDavid Howells { "ro", SB_RDONLY },
463e1aeb00SDavid Howells { "sync", SB_SYNCHRONOUS },
4734264ae3SAl Viro { },
483e1aeb00SDavid Howells };
493e1aeb00SDavid Howells
503e1aeb00SDavid Howells static const struct constant_table common_clear_sb_flag[] = {
513e1aeb00SDavid Howells { "async", SB_SYNCHRONOUS },
523e1aeb00SDavid Howells { "nolazytime", SB_LAZYTIME },
533e1aeb00SDavid Howells { "nomand", SB_MANDLOCK },
543e1aeb00SDavid Howells { "rw", SB_RDONLY },
5534264ae3SAl Viro { },
563e1aeb00SDavid Howells };
573e1aeb00SDavid Howells
583e1aeb00SDavid Howells /*
593e1aeb00SDavid Howells * Check for a common mount option that manipulates s_flags.
603e1aeb00SDavid Howells */
vfs_parse_sb_flag(struct fs_context * fc,const char * key)613e1aeb00SDavid Howells static int vfs_parse_sb_flag(struct fs_context *fc, const char *key)
623e1aeb00SDavid Howells {
633e1aeb00SDavid Howells unsigned int token;
643e1aeb00SDavid Howells
653e1aeb00SDavid Howells token = lookup_constant(common_set_sb_flag, key, 0);
663e1aeb00SDavid Howells if (token) {
673e1aeb00SDavid Howells fc->sb_flags |= token;
683e1aeb00SDavid Howells fc->sb_flags_mask |= token;
693e1aeb00SDavid Howells return 0;
703e1aeb00SDavid Howells }
713e1aeb00SDavid Howells
723e1aeb00SDavid Howells token = lookup_constant(common_clear_sb_flag, key, 0);
733e1aeb00SDavid Howells if (token) {
743e1aeb00SDavid Howells fc->sb_flags &= ~token;
753e1aeb00SDavid Howells fc->sb_flags_mask |= token;
763e1aeb00SDavid Howells return 0;
773e1aeb00SDavid Howells }
783e1aeb00SDavid Howells
793e1aeb00SDavid Howells return -ENOPARAM;
803e1aeb00SDavid Howells }
813e1aeb00SDavid Howells
823e1aeb00SDavid Howells /**
83d1d488d8SChristian Brauner * vfs_parse_fs_param_source - Handle setting "source" via parameter
84d1d488d8SChristian Brauner * @fc: The filesystem context to modify
85d1d488d8SChristian Brauner * @param: The parameter
86d1d488d8SChristian Brauner *
87d1d488d8SChristian Brauner * This is a simple helper for filesystems to verify that the "source" they
88d1d488d8SChristian Brauner * accept is sane.
89d1d488d8SChristian Brauner *
90d1d488d8SChristian Brauner * Returns 0 on success, -ENOPARAM if this is not "source" parameter, and
91d1d488d8SChristian Brauner * -EINVAL otherwise. In the event of failure, supplementary error information
92d1d488d8SChristian Brauner * is logged.
93d1d488d8SChristian Brauner */
vfs_parse_fs_param_source(struct fs_context * fc,struct fs_parameter * param)94d1d488d8SChristian Brauner int vfs_parse_fs_param_source(struct fs_context *fc, struct fs_parameter *param)
95d1d488d8SChristian Brauner {
96d1d488d8SChristian Brauner if (strcmp(param->key, "source") != 0)
97d1d488d8SChristian Brauner return -ENOPARAM;
98d1d488d8SChristian Brauner
99d1d488d8SChristian Brauner if (param->type != fs_value_is_string)
100d1d488d8SChristian Brauner return invalf(fc, "Non-string source");
101d1d488d8SChristian Brauner
102d1d488d8SChristian Brauner if (fc->source)
103d1d488d8SChristian Brauner return invalf(fc, "Multiple sources");
104d1d488d8SChristian Brauner
105d1d488d8SChristian Brauner fc->source = param->string;
106d1d488d8SChristian Brauner param->string = NULL;
107d1d488d8SChristian Brauner return 0;
108d1d488d8SChristian Brauner }
109d1d488d8SChristian Brauner EXPORT_SYMBOL(vfs_parse_fs_param_source);
110d1d488d8SChristian Brauner
111d1d488d8SChristian Brauner /**
1123e1aeb00SDavid Howells * vfs_parse_fs_param - Add a single parameter to a superblock config
1133e1aeb00SDavid Howells * @fc: The filesystem context to modify
1143e1aeb00SDavid Howells * @param: The parameter
1153e1aeb00SDavid Howells *
1163e1aeb00SDavid Howells * A single mount option in string form is applied to the filesystem context
1173e1aeb00SDavid Howells * being set up. Certain standard options (for example "ro") are translated
1183e1aeb00SDavid Howells * into flag bits without going to the filesystem. The active security module
1193e1aeb00SDavid Howells * is allowed to observe and poach options. Any other options are passed over
1203e1aeb00SDavid Howells * to the filesystem to parse.
1213e1aeb00SDavid Howells *
1223e1aeb00SDavid Howells * This may be called multiple times for a context.
1233e1aeb00SDavid Howells *
1243e1aeb00SDavid Howells * Returns 0 on success and a negative error code on failure. In the event of
1253e1aeb00SDavid Howells * failure, supplementary error information may have been set.
1263e1aeb00SDavid Howells */
vfs_parse_fs_param(struct fs_context * fc,struct fs_parameter * param)1273e1aeb00SDavid Howells int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
1283e1aeb00SDavid Howells {
1293e1aeb00SDavid Howells int ret;
1303e1aeb00SDavid Howells
1313e1aeb00SDavid Howells if (!param->key)
1323e1aeb00SDavid Howells return invalf(fc, "Unnamed parameter\n");
1333e1aeb00SDavid Howells
1343e1aeb00SDavid Howells ret = vfs_parse_sb_flag(fc, param->key);
1353e1aeb00SDavid Howells if (ret != -ENOPARAM)
1363e1aeb00SDavid Howells return ret;
1373e1aeb00SDavid Howells
1383e1aeb00SDavid Howells ret = security_fs_context_parse_param(fc, param);
1393e1aeb00SDavid Howells if (ret != -ENOPARAM)
1403e1aeb00SDavid Howells /* Param belongs to the LSM or is disallowed by the LSM; so
1413e1aeb00SDavid Howells * don't pass to the FS.
1423e1aeb00SDavid Howells */
1433e1aeb00SDavid Howells return ret;
1443e1aeb00SDavid Howells
1453e1aeb00SDavid Howells if (fc->ops->parse_param) {
1463e1aeb00SDavid Howells ret = fc->ops->parse_param(fc, param);
1473e1aeb00SDavid Howells if (ret != -ENOPARAM)
1483e1aeb00SDavid Howells return ret;
1493e1aeb00SDavid Howells }
1503e1aeb00SDavid Howells
1513e1aeb00SDavid Howells /* If the filesystem doesn't take any arguments, give it the
1523e1aeb00SDavid Howells * default handling of source.
1533e1aeb00SDavid Howells */
154d1d488d8SChristian Brauner ret = vfs_parse_fs_param_source(fc, param);
155d1d488d8SChristian Brauner if (ret != -ENOPARAM)
156d1d488d8SChristian Brauner return ret;
1573e1aeb00SDavid Howells
1583e1aeb00SDavid Howells return invalf(fc, "%s: Unknown parameter '%s'",
1593e1aeb00SDavid Howells fc->fs_type->name, param->key);
1603e1aeb00SDavid Howells }
1613e1aeb00SDavid Howells EXPORT_SYMBOL(vfs_parse_fs_param);
1623e1aeb00SDavid Howells
1633e1aeb00SDavid Howells /**
1643e1aeb00SDavid Howells * vfs_parse_fs_string - Convenience function to just parse a string.
16535931eb3SMatthew Wilcox (Oracle) * @fc: Filesystem context.
16635931eb3SMatthew Wilcox (Oracle) * @key: Parameter name.
16735931eb3SMatthew Wilcox (Oracle) * @value: Default value.
16835931eb3SMatthew Wilcox (Oracle) * @v_size: Maximum number of bytes in the value.
1693e1aeb00SDavid Howells */
vfs_parse_fs_string(struct fs_context * fc,const char * key,const char * value,size_t v_size)1703e1aeb00SDavid Howells int vfs_parse_fs_string(struct fs_context *fc, const char *key,
1713e1aeb00SDavid Howells const char *value, size_t v_size)
1723e1aeb00SDavid Howells {
1733e1aeb00SDavid Howells int ret;
1743e1aeb00SDavid Howells
1753e1aeb00SDavid Howells struct fs_parameter param = {
1763e1aeb00SDavid Howells .key = key,
1770f89589aSAl Viro .type = fs_value_is_flag,
1783e1aeb00SDavid Howells .size = v_size,
1793e1aeb00SDavid Howells };
1803e1aeb00SDavid Howells
1810f89589aSAl Viro if (value) {
1823e1aeb00SDavid Howells param.string = kmemdup_nul(value, v_size, GFP_KERNEL);
1833e1aeb00SDavid Howells if (!param.string)
1843e1aeb00SDavid Howells return -ENOMEM;
1850f89589aSAl Viro param.type = fs_value_is_string;
1863e1aeb00SDavid Howells }
1873e1aeb00SDavid Howells
1883e1aeb00SDavid Howells ret = vfs_parse_fs_param(fc, ¶m);
1893e1aeb00SDavid Howells kfree(param.string);
1903e1aeb00SDavid Howells return ret;
1913e1aeb00SDavid Howells }
1923e1aeb00SDavid Howells EXPORT_SYMBOL(vfs_parse_fs_string);
1933e1aeb00SDavid Howells
1943e1aeb00SDavid Howells /**
195*e001d144SAmir Goldstein * vfs_parse_monolithic_sep - Parse key[=val][,key[=val]]* mount data
19635931eb3SMatthew Wilcox (Oracle) * @fc: The superblock configuration to fill in.
1973e1aeb00SDavid Howells * @data: The data to parse
198*e001d144SAmir Goldstein * @sep: callback for separating next option
1993e1aeb00SDavid Howells *
200*e001d144SAmir Goldstein * Parse a blob of data that's in key[=val][,key[=val]]* form with a custom
201*e001d144SAmir Goldstein * option separator callback.
2023e1aeb00SDavid Howells *
2033e1aeb00SDavid Howells * Returns 0 on success or the error returned by the ->parse_option() fs_context
2043e1aeb00SDavid Howells * operation on failure.
2053e1aeb00SDavid Howells */
vfs_parse_monolithic_sep(struct fs_context * fc,void * data,char * (* sep)(char **))206*e001d144SAmir Goldstein int vfs_parse_monolithic_sep(struct fs_context *fc, void *data,
207*e001d144SAmir Goldstein char *(*sep)(char **))
2083e1aeb00SDavid Howells {
2093e1aeb00SDavid Howells char *options = data, *key;
2103e1aeb00SDavid Howells int ret = 0;
2113e1aeb00SDavid Howells
2123e1aeb00SDavid Howells if (!options)
2133e1aeb00SDavid Howells return 0;
2143e1aeb00SDavid Howells
2153e1aeb00SDavid Howells ret = security_sb_eat_lsm_opts(options, &fc->security);
2163e1aeb00SDavid Howells if (ret)
2173e1aeb00SDavid Howells return ret;
2183e1aeb00SDavid Howells
219*e001d144SAmir Goldstein while ((key = sep(&options)) != NULL) {
2203e1aeb00SDavid Howells if (*key) {
2213e1aeb00SDavid Howells size_t v_len = 0;
2223e1aeb00SDavid Howells char *value = strchr(key, '=');
2233e1aeb00SDavid Howells
2243e1aeb00SDavid Howells if (value) {
2253e1aeb00SDavid Howells if (value == key)
2263e1aeb00SDavid Howells continue;
2273e1aeb00SDavid Howells *value++ = 0;
2283e1aeb00SDavid Howells v_len = strlen(value);
2293e1aeb00SDavid Howells }
2303e1aeb00SDavid Howells ret = vfs_parse_fs_string(fc, key, value, v_len);
2313e1aeb00SDavid Howells if (ret < 0)
2323e1aeb00SDavid Howells break;
2333e1aeb00SDavid Howells }
2343e1aeb00SDavid Howells }
2353e1aeb00SDavid Howells
2363e1aeb00SDavid Howells return ret;
2373e1aeb00SDavid Howells }
238*e001d144SAmir Goldstein EXPORT_SYMBOL(vfs_parse_monolithic_sep);
239*e001d144SAmir Goldstein
vfs_parse_comma_sep(char ** s)240*e001d144SAmir Goldstein static char *vfs_parse_comma_sep(char **s)
241*e001d144SAmir Goldstein {
242*e001d144SAmir Goldstein return strsep(s, ",");
243*e001d144SAmir Goldstein }
244*e001d144SAmir Goldstein
245*e001d144SAmir Goldstein /**
246*e001d144SAmir Goldstein * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data
247*e001d144SAmir Goldstein * @fc: The superblock configuration to fill in.
248*e001d144SAmir Goldstein * @data: The data to parse
249*e001d144SAmir Goldstein *
250*e001d144SAmir Goldstein * Parse a blob of data that's in key[=val][,key[=val]]* form. This can be
251*e001d144SAmir Goldstein * called from the ->monolithic_mount_data() fs_context operation.
252*e001d144SAmir Goldstein *
253*e001d144SAmir Goldstein * Returns 0 on success or the error returned by the ->parse_option() fs_context
254*e001d144SAmir Goldstein * operation on failure.
255*e001d144SAmir Goldstein */
generic_parse_monolithic(struct fs_context * fc,void * data)256*e001d144SAmir Goldstein int generic_parse_monolithic(struct fs_context *fc, void *data)
257*e001d144SAmir Goldstein {
258*e001d144SAmir Goldstein return vfs_parse_monolithic_sep(fc, data, vfs_parse_comma_sep);
259*e001d144SAmir Goldstein }
2603e1aeb00SDavid Howells EXPORT_SYMBOL(generic_parse_monolithic);
2613e1aeb00SDavid Howells
2629bc61ab1SDavid Howells /**
2639bc61ab1SDavid Howells * alloc_fs_context - Create a filesystem context.
2649bc61ab1SDavid Howells * @fs_type: The filesystem type.
2659bc61ab1SDavid Howells * @reference: The dentry from which this one derives (or NULL)
2669bc61ab1SDavid Howells * @sb_flags: Filesystem/superblock flags (SB_*)
2679bc61ab1SDavid Howells * @sb_flags_mask: Applicable members of @sb_flags
2689bc61ab1SDavid Howells * @purpose: The purpose that this configuration shall be used for.
2699bc61ab1SDavid Howells *
2709bc61ab1SDavid Howells * Open a filesystem and create a mount context. The mount context is
2719bc61ab1SDavid Howells * initialised with the supplied flags and, if a submount/automount from
2729bc61ab1SDavid Howells * another superblock (referred to by @reference) is supplied, may have
2739bc61ab1SDavid Howells * parameters such as namespaces copied across from that superblock.
2749bc61ab1SDavid Howells */
alloc_fs_context(struct file_system_type * fs_type,struct dentry * reference,unsigned int sb_flags,unsigned int sb_flags_mask,enum fs_context_purpose purpose)2759bc61ab1SDavid Howells static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
2769bc61ab1SDavid Howells struct dentry *reference,
2779bc61ab1SDavid Howells unsigned int sb_flags,
2789bc61ab1SDavid Howells unsigned int sb_flags_mask,
2799bc61ab1SDavid Howells enum fs_context_purpose purpose)
2809bc61ab1SDavid Howells {
281f3a09c92SAl Viro int (*init_fs_context)(struct fs_context *);
2829bc61ab1SDavid Howells struct fs_context *fc;
2839bc61ab1SDavid Howells int ret = -ENOMEM;
2849bc61ab1SDavid Howells
285bb902cb4SYutian Yang fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL_ACCOUNT);
2869bc61ab1SDavid Howells if (!fc)
2879bc61ab1SDavid Howells return ERR_PTR(-ENOMEM);
2889bc61ab1SDavid Howells
2899bc61ab1SDavid Howells fc->purpose = purpose;
2909bc61ab1SDavid Howells fc->sb_flags = sb_flags;
2919bc61ab1SDavid Howells fc->sb_flags_mask = sb_flags_mask;
2929bc61ab1SDavid Howells fc->fs_type = get_filesystem(fs_type);
2939bc61ab1SDavid Howells fc->cred = get_current_cred();
2949bc61ab1SDavid Howells fc->net_ns = get_net(current->nsproxy->net_ns);
295cc3c0b53SAl Viro fc->log.prefix = fs_type->name;
2969bc61ab1SDavid Howells
29724dcb3d9SDavid Howells mutex_init(&fc->uapi_mutex);
29824dcb3d9SDavid Howells
2999bc61ab1SDavid Howells switch (purpose) {
3009bc61ab1SDavid Howells case FS_CONTEXT_FOR_MOUNT:
3019bc61ab1SDavid Howells fc->user_ns = get_user_ns(fc->cred->user_ns);
3029bc61ab1SDavid Howells break;
303e1a91586SAl Viro case FS_CONTEXT_FOR_SUBMOUNT:
304e1a91586SAl Viro fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
305e1a91586SAl Viro break;
3068d0347f6SDavid Howells case FS_CONTEXT_FOR_RECONFIGURE:
3078d0347f6SDavid Howells atomic_inc(&reference->d_sb->s_active);
3081dd9bc08SEric Biggers fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
3098d0347f6SDavid Howells fc->root = dget(reference);
3108d0347f6SDavid Howells break;
3119bc61ab1SDavid Howells }
3129bc61ab1SDavid Howells
313f3a09c92SAl Viro /* TODO: Make all filesystems support this unconditionally */
314f3a09c92SAl Viro init_fs_context = fc->fs_type->init_fs_context;
315f3a09c92SAl Viro if (!init_fs_context)
316f3a09c92SAl Viro init_fs_context = legacy_init_fs_context;
317f3a09c92SAl Viro
318f3a09c92SAl Viro ret = init_fs_context(fc);
3199bc61ab1SDavid Howells if (ret < 0)
3209bc61ab1SDavid Howells goto err_fc;
3219bc61ab1SDavid Howells fc->need_free = true;
3229bc61ab1SDavid Howells return fc;
3239bc61ab1SDavid Howells
3249bc61ab1SDavid Howells err_fc:
3259bc61ab1SDavid Howells put_fs_context(fc);
3269bc61ab1SDavid Howells return ERR_PTR(ret);
3279bc61ab1SDavid Howells }
3289bc61ab1SDavid Howells
fs_context_for_mount(struct file_system_type * fs_type,unsigned int sb_flags)3299bc61ab1SDavid Howells struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
3309bc61ab1SDavid Howells unsigned int sb_flags)
3319bc61ab1SDavid Howells {
3329bc61ab1SDavid Howells return alloc_fs_context(fs_type, NULL, sb_flags, 0,
3339bc61ab1SDavid Howells FS_CONTEXT_FOR_MOUNT);
3349bc61ab1SDavid Howells }
3359bc61ab1SDavid Howells EXPORT_SYMBOL(fs_context_for_mount);
3369bc61ab1SDavid Howells
fs_context_for_reconfigure(struct dentry * dentry,unsigned int sb_flags,unsigned int sb_flags_mask)3378d0347f6SDavid Howells struct fs_context *fs_context_for_reconfigure(struct dentry *dentry,
3388d0347f6SDavid Howells unsigned int sb_flags,
3398d0347f6SDavid Howells unsigned int sb_flags_mask)
3408d0347f6SDavid Howells {
3418d0347f6SDavid Howells return alloc_fs_context(dentry->d_sb->s_type, dentry, sb_flags,
3428d0347f6SDavid Howells sb_flags_mask, FS_CONTEXT_FOR_RECONFIGURE);
3438d0347f6SDavid Howells }
3448d0347f6SDavid Howells EXPORT_SYMBOL(fs_context_for_reconfigure);
3458d0347f6SDavid Howells
346d80a8f1bSDavid Howells /**
347d80a8f1bSDavid Howells * fs_context_for_submount: allocate a new fs_context for a submount
348d80a8f1bSDavid Howells * @type: file_system_type of the new context
349d80a8f1bSDavid Howells * @reference: reference dentry from which to copy relevant info
350d80a8f1bSDavid Howells *
351d80a8f1bSDavid Howells * Allocate a new fs_context suitable for a submount. This also ensures that
352d80a8f1bSDavid Howells * the fc->security object is inherited from @reference (if needed).
353d80a8f1bSDavid Howells */
fs_context_for_submount(struct file_system_type * type,struct dentry * reference)354e1a91586SAl Viro struct fs_context *fs_context_for_submount(struct file_system_type *type,
355e1a91586SAl Viro struct dentry *reference)
356e1a91586SAl Viro {
357d80a8f1bSDavid Howells struct fs_context *fc;
358d80a8f1bSDavid Howells int ret;
359d80a8f1bSDavid Howells
360d80a8f1bSDavid Howells fc = alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT);
361d80a8f1bSDavid Howells if (IS_ERR(fc))
362d80a8f1bSDavid Howells return fc;
363d80a8f1bSDavid Howells
364d80a8f1bSDavid Howells ret = security_fs_context_submount(fc, reference->d_sb);
365d80a8f1bSDavid Howells if (ret) {
366d80a8f1bSDavid Howells put_fs_context(fc);
367d80a8f1bSDavid Howells return ERR_PTR(ret);
368d80a8f1bSDavid Howells }
369d80a8f1bSDavid Howells
370d80a8f1bSDavid Howells return fc;
371e1a91586SAl Viro }
372e1a91586SAl Viro EXPORT_SYMBOL(fs_context_for_submount);
373e1a91586SAl Viro
fc_drop_locked(struct fs_context * fc)374c9ce29edSAl Viro void fc_drop_locked(struct fs_context *fc)
375c9ce29edSAl Viro {
376c9ce29edSAl Viro struct super_block *sb = fc->root->d_sb;
377c9ce29edSAl Viro dput(fc->root);
378c9ce29edSAl Viro fc->root = NULL;
379c9ce29edSAl Viro deactivate_locked_super(sb);
380c9ce29edSAl Viro }
381c9ce29edSAl Viro
3829bc61ab1SDavid Howells static void legacy_fs_context_free(struct fs_context *fc);
3838d0347f6SDavid Howells
3849bc61ab1SDavid Howells /**
38535931eb3SMatthew Wilcox (Oracle) * vfs_dup_fs_context - Duplicate a filesystem context.
3860b52075eSAl Viro * @src_fc: The context to copy.
3870b52075eSAl Viro */
vfs_dup_fs_context(struct fs_context * src_fc)3880b52075eSAl Viro struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc)
3890b52075eSAl Viro {
3900b52075eSAl Viro struct fs_context *fc;
3910b52075eSAl Viro int ret;
3920b52075eSAl Viro
3930b52075eSAl Viro if (!src_fc->ops->dup)
3940b52075eSAl Viro return ERR_PTR(-EOPNOTSUPP);
3950b52075eSAl Viro
3960b52075eSAl Viro fc = kmemdup(src_fc, sizeof(struct fs_context), GFP_KERNEL);
3970b52075eSAl Viro if (!fc)
3980b52075eSAl Viro return ERR_PTR(-ENOMEM);
3990b52075eSAl Viro
40024dcb3d9SDavid Howells mutex_init(&fc->uapi_mutex);
40124dcb3d9SDavid Howells
4020b52075eSAl Viro fc->fs_private = NULL;
4030b52075eSAl Viro fc->s_fs_info = NULL;
4040b52075eSAl Viro fc->source = NULL;
4050b52075eSAl Viro fc->security = NULL;
4060b52075eSAl Viro get_filesystem(fc->fs_type);
4070b52075eSAl Viro get_net(fc->net_ns);
4080b52075eSAl Viro get_user_ns(fc->user_ns);
4090b52075eSAl Viro get_cred(fc->cred);
410cc3c0b53SAl Viro if (fc->log.log)
411cc3c0b53SAl Viro refcount_inc(&fc->log.log->usage);
4120b52075eSAl Viro
4130b52075eSAl Viro /* Can't call put until we've called ->dup */
4140b52075eSAl Viro ret = fc->ops->dup(fc, src_fc);
4150b52075eSAl Viro if (ret < 0)
4160b52075eSAl Viro goto err_fc;
4170b52075eSAl Viro
4180b52075eSAl Viro ret = security_fs_context_dup(fc, src_fc);
4190b52075eSAl Viro if (ret < 0)
4200b52075eSAl Viro goto err_fc;
4210b52075eSAl Viro return fc;
4220b52075eSAl Viro
4230b52075eSAl Viro err_fc:
4240b52075eSAl Viro put_fs_context(fc);
4250b52075eSAl Viro return ERR_PTR(ret);
4260b52075eSAl Viro }
4270b52075eSAl Viro EXPORT_SYMBOL(vfs_dup_fs_context);
4280b52075eSAl Viro
429e7582e16SDavid Howells /**
430e7582e16SDavid Howells * logfc - Log a message to a filesystem context
43135931eb3SMatthew Wilcox (Oracle) * @log: The filesystem context to log to, or NULL to use printk.
43235931eb3SMatthew Wilcox (Oracle) * @prefix: A string to prefix the output with, or NULL.
43335931eb3SMatthew Wilcox (Oracle) * @level: 'w' for a warning, 'e' for an error. Anything else is a notice.
434e7582e16SDavid Howells * @fmt: The format of the buffer.
435e7582e16SDavid Howells */
logfc(struct fc_log * log,const char * prefix,char level,const char * fmt,...)4369f09f649SAl Viro void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...)
437e7582e16SDavid Howells {
438e7582e16SDavid Howells va_list va;
4399f09f649SAl Viro struct va_format vaf = {.fmt = fmt, .va = &va};
440e7582e16SDavid Howells
441e7582e16SDavid Howells va_start(va, fmt);
442007ec26cSDavid Howells if (!log) {
4439f09f649SAl Viro switch (level) {
444007ec26cSDavid Howells case 'w':
4459f09f649SAl Viro printk(KERN_WARNING "%s%s%pV\n", prefix ? prefix : "",
4469f09f649SAl Viro prefix ? ": " : "", &vaf);
447007ec26cSDavid Howells break;
448007ec26cSDavid Howells case 'e':
4499f09f649SAl Viro printk(KERN_ERR "%s%s%pV\n", prefix ? prefix : "",
4509f09f649SAl Viro prefix ? ": " : "", &vaf);
451007ec26cSDavid Howells break;
452007ec26cSDavid Howells default:
4539f09f649SAl Viro printk(KERN_NOTICE "%s%s%pV\n", prefix ? prefix : "",
4549f09f649SAl Viro prefix ? ": " : "", &vaf);
455007ec26cSDavid Howells break;
456007ec26cSDavid Howells }
457007ec26cSDavid Howells } else {
458007ec26cSDavid Howells unsigned int logsize = ARRAY_SIZE(log->buffer);
459007ec26cSDavid Howells u8 index;
4609f09f649SAl Viro char *q = kasprintf(GFP_KERNEL, "%c %s%s%pV\n", level,
4619f09f649SAl Viro prefix ? prefix : "",
4629f09f649SAl Viro prefix ? ": " : "", &vaf);
463007ec26cSDavid Howells
464007ec26cSDavid Howells index = log->head & (logsize - 1);
465007ec26cSDavid Howells BUILD_BUG_ON(sizeof(log->head) != sizeof(u8) ||
466007ec26cSDavid Howells sizeof(log->tail) != sizeof(u8));
467007ec26cSDavid Howells if ((u8)(log->head - log->tail) == logsize) {
468007ec26cSDavid Howells /* The buffer is full, discard the oldest message */
469007ec26cSDavid Howells if (log->need_free & (1 << index))
470007ec26cSDavid Howells kfree(log->buffer[index]);
471007ec26cSDavid Howells log->tail++;
472007ec26cSDavid Howells }
473007ec26cSDavid Howells
4749f09f649SAl Viro log->buffer[index] = q ? q : "OOM: Can't store error string";
4759f09f649SAl Viro if (q)
4769f09f649SAl Viro log->need_free |= 1 << index;
4779f09f649SAl Viro else
478007ec26cSDavid Howells log->need_free &= ~(1 << index);
479007ec26cSDavid Howells log->head++;
480007ec26cSDavid Howells }
481e7582e16SDavid Howells va_end(va);
482e7582e16SDavid Howells }
483e7582e16SDavid Howells EXPORT_SYMBOL(logfc);
484007ec26cSDavid Howells
485007ec26cSDavid Howells /*
486007ec26cSDavid Howells * Free a logging structure.
487007ec26cSDavid Howells */
put_fc_log(struct fs_context * fc)488007ec26cSDavid Howells static void put_fc_log(struct fs_context *fc)
489007ec26cSDavid Howells {
490cc3c0b53SAl Viro struct fc_log *log = fc->log.log;
491007ec26cSDavid Howells int i;
492007ec26cSDavid Howells
493007ec26cSDavid Howells if (log) {
494007ec26cSDavid Howells if (refcount_dec_and_test(&log->usage)) {
495cc3c0b53SAl Viro fc->log.log = NULL;
496007ec26cSDavid Howells for (i = 0; i <= 7; i++)
497007ec26cSDavid Howells if (log->need_free & (1 << i))
498007ec26cSDavid Howells kfree(log->buffer[i]);
499007ec26cSDavid Howells kfree(log);
500007ec26cSDavid Howells }
501007ec26cSDavid Howells }
502007ec26cSDavid Howells }
503e7582e16SDavid Howells
5040b52075eSAl Viro /**
5059bc61ab1SDavid Howells * put_fs_context - Dispose of a superblock configuration context.
5069bc61ab1SDavid Howells * @fc: The context to dispose of.
5079bc61ab1SDavid Howells */
put_fs_context(struct fs_context * fc)5089bc61ab1SDavid Howells void put_fs_context(struct fs_context *fc)
5099bc61ab1SDavid Howells {
5109bc61ab1SDavid Howells struct super_block *sb;
5119bc61ab1SDavid Howells
5129bc61ab1SDavid Howells if (fc->root) {
5139bc61ab1SDavid Howells sb = fc->root->d_sb;
5149bc61ab1SDavid Howells dput(fc->root);
5159bc61ab1SDavid Howells fc->root = NULL;
5169bc61ab1SDavid Howells deactivate_super(sb);
5179bc61ab1SDavid Howells }
5189bc61ab1SDavid Howells
519f3a09c92SAl Viro if (fc->need_free && fc->ops && fc->ops->free)
520f3a09c92SAl Viro fc->ops->free(fc);
5219bc61ab1SDavid Howells
5229bc61ab1SDavid Howells security_free_mnt_opts(&fc->security);
5239bc61ab1SDavid Howells put_net(fc->net_ns);
5249bc61ab1SDavid Howells put_user_ns(fc->user_ns);
5259bc61ab1SDavid Howells put_cred(fc->cred);
526007ec26cSDavid Howells put_fc_log(fc);
5279bc61ab1SDavid Howells put_filesystem(fc->fs_type);
5289bc61ab1SDavid Howells kfree(fc->source);
5299bc61ab1SDavid Howells kfree(fc);
5309bc61ab1SDavid Howells }
5319bc61ab1SDavid Howells EXPORT_SYMBOL(put_fs_context);
5329bc61ab1SDavid Howells
5339bc61ab1SDavid Howells /*
5349bc61ab1SDavid Howells * Free the config for a filesystem that doesn't support fs_context.
5359bc61ab1SDavid Howells */
legacy_fs_context_free(struct fs_context * fc)5369bc61ab1SDavid Howells static void legacy_fs_context_free(struct fs_context *fc)
5379bc61ab1SDavid Howells {
5383e1aeb00SDavid Howells struct legacy_fs_context *ctx = fc->fs_private;
5393e1aeb00SDavid Howells
5403e1aeb00SDavid Howells if (ctx) {
5413e1aeb00SDavid Howells if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS)
5423e1aeb00SDavid Howells kfree(ctx->legacy_data);
5433e1aeb00SDavid Howells kfree(ctx);
5443e1aeb00SDavid Howells }
5453e1aeb00SDavid Howells }
5463e1aeb00SDavid Howells
5473e1aeb00SDavid Howells /*
5480b52075eSAl Viro * Duplicate a legacy config.
5490b52075eSAl Viro */
legacy_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)5500b52075eSAl Viro static int legacy_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
5510b52075eSAl Viro {
5520b52075eSAl Viro struct legacy_fs_context *ctx;
5530b52075eSAl Viro struct legacy_fs_context *src_ctx = src_fc->fs_private;
5540b52075eSAl Viro
5550b52075eSAl Viro ctx = kmemdup(src_ctx, sizeof(*src_ctx), GFP_KERNEL);
5560b52075eSAl Viro if (!ctx)
5570b52075eSAl Viro return -ENOMEM;
5580b52075eSAl Viro
5590b52075eSAl Viro if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS) {
5600b52075eSAl Viro ctx->legacy_data = kmemdup(src_ctx->legacy_data,
5610b52075eSAl Viro src_ctx->data_size, GFP_KERNEL);
5620b52075eSAl Viro if (!ctx->legacy_data) {
5630b52075eSAl Viro kfree(ctx);
5640b52075eSAl Viro return -ENOMEM;
5650b52075eSAl Viro }
5660b52075eSAl Viro }
5670b52075eSAl Viro
5680b52075eSAl Viro fc->fs_private = ctx;
5690b52075eSAl Viro return 0;
5700b52075eSAl Viro }
5710b52075eSAl Viro
5720b52075eSAl Viro /*
5733e1aeb00SDavid Howells * Add a parameter to a legacy config. We build up a comma-separated list of
5743e1aeb00SDavid Howells * options.
5753e1aeb00SDavid Howells */
legacy_parse_param(struct fs_context * fc,struct fs_parameter * param)5763e1aeb00SDavid Howells static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param)
5773e1aeb00SDavid Howells {
5783e1aeb00SDavid Howells struct legacy_fs_context *ctx = fc->fs_private;
5793e1aeb00SDavid Howells unsigned int size = ctx->data_size;
5803e1aeb00SDavid Howells size_t len = 0;
581d1d488d8SChristian Brauner int ret;
5823e1aeb00SDavid Howells
583d1d488d8SChristian Brauner ret = vfs_parse_fs_param_source(fc, param);
584d1d488d8SChristian Brauner if (ret != -ENOPARAM)
585d1d488d8SChristian Brauner return ret;
5863e1aeb00SDavid Howells
5873e1aeb00SDavid Howells if (ctx->param_type == LEGACY_FS_MONOLITHIC_PARAMS)
5883e1aeb00SDavid Howells return invalf(fc, "VFS: Legacy: Can't mix monolithic and individual options");
5893e1aeb00SDavid Howells
5903e1aeb00SDavid Howells switch (param->type) {
5913e1aeb00SDavid Howells case fs_value_is_string:
5923e1aeb00SDavid Howells len = 1 + param->size;
593df561f66SGustavo A. R. Silva fallthrough;
5943e1aeb00SDavid Howells case fs_value_is_flag:
5953e1aeb00SDavid Howells len += strlen(param->key);
5963e1aeb00SDavid Howells break;
5973e1aeb00SDavid Howells default:
5983e1aeb00SDavid Howells return invalf(fc, "VFS: Legacy: Parameter type for '%s' not supported",
5993e1aeb00SDavid Howells param->key);
6003e1aeb00SDavid Howells }
6013e1aeb00SDavid Howells
602722d9484SJamie Hill-Daniel if (size + len + 2 > PAGE_SIZE)
6033e1aeb00SDavid Howells return invalf(fc, "VFS: Legacy: Cumulative options too large");
6043e1aeb00SDavid Howells if (strchr(param->key, ',') ||
6053e1aeb00SDavid Howells (param->type == fs_value_is_string &&
6063e1aeb00SDavid Howells memchr(param->string, ',', param->size)))
6073e1aeb00SDavid Howells return invalf(fc, "VFS: Legacy: Option '%s' contained comma",
6083e1aeb00SDavid Howells param->key);
6093e1aeb00SDavid Howells if (!ctx->legacy_data) {
6103e1aeb00SDavid Howells ctx->legacy_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
6113e1aeb00SDavid Howells if (!ctx->legacy_data)
6123e1aeb00SDavid Howells return -ENOMEM;
6133e1aeb00SDavid Howells }
6143e1aeb00SDavid Howells
61562176420SThomas Weißschuh if (size)
6163e1aeb00SDavid Howells ctx->legacy_data[size++] = ',';
6173e1aeb00SDavid Howells len = strlen(param->key);
6183e1aeb00SDavid Howells memcpy(ctx->legacy_data + size, param->key, len);
6193e1aeb00SDavid Howells size += len;
6203e1aeb00SDavid Howells if (param->type == fs_value_is_string) {
6213e1aeb00SDavid Howells ctx->legacy_data[size++] = '=';
6223e1aeb00SDavid Howells memcpy(ctx->legacy_data + size, param->string, param->size);
6233e1aeb00SDavid Howells size += param->size;
6243e1aeb00SDavid Howells }
6253e1aeb00SDavid Howells ctx->legacy_data[size] = '\0';
6263e1aeb00SDavid Howells ctx->data_size = size;
6273e1aeb00SDavid Howells ctx->param_type = LEGACY_FS_INDIVIDUAL_PARAMS;
6283e1aeb00SDavid Howells return 0;
6299bc61ab1SDavid Howells }
6309bc61ab1SDavid Howells
6319bc61ab1SDavid Howells /*
6329bc61ab1SDavid Howells * Add monolithic mount data.
6339bc61ab1SDavid Howells */
legacy_parse_monolithic(struct fs_context * fc,void * data)6349bc61ab1SDavid Howells static int legacy_parse_monolithic(struct fs_context *fc, void *data)
6359bc61ab1SDavid Howells {
6369bc61ab1SDavid Howells struct legacy_fs_context *ctx = fc->fs_private;
6373e1aeb00SDavid Howells
6383e1aeb00SDavid Howells if (ctx->param_type != LEGACY_FS_UNSET_PARAMS) {
6393e1aeb00SDavid Howells pr_warn("VFS: Can't mix monolithic and individual options\n");
6403e1aeb00SDavid Howells return -EINVAL;
6413e1aeb00SDavid Howells }
6423e1aeb00SDavid Howells
6439bc61ab1SDavid Howells ctx->legacy_data = data;
6443e1aeb00SDavid Howells ctx->param_type = LEGACY_FS_MONOLITHIC_PARAMS;
6459bc61ab1SDavid Howells if (!ctx->legacy_data)
6469bc61ab1SDavid Howells return 0;
6473e1aeb00SDavid Howells
6489bc61ab1SDavid Howells if (fc->fs_type->fs_flags & FS_BINARY_MOUNTDATA)
6499bc61ab1SDavid Howells return 0;
6509bc61ab1SDavid Howells return security_sb_eat_lsm_opts(ctx->legacy_data, &fc->security);
6519bc61ab1SDavid Howells }
6529bc61ab1SDavid Howells
6539bc61ab1SDavid Howells /*
6549bc61ab1SDavid Howells * Get a mountable root with the legacy mount command.
6559bc61ab1SDavid Howells */
legacy_get_tree(struct fs_context * fc)656f3a09c92SAl Viro static int legacy_get_tree(struct fs_context *fc)
6579bc61ab1SDavid Howells {
6589bc61ab1SDavid Howells struct legacy_fs_context *ctx = fc->fs_private;
6599bc61ab1SDavid Howells struct super_block *sb;
6609bc61ab1SDavid Howells struct dentry *root;
6619bc61ab1SDavid Howells
6629bc61ab1SDavid Howells root = fc->fs_type->mount(fc->fs_type, fc->sb_flags,
6639bc61ab1SDavid Howells fc->source, ctx->legacy_data);
6649bc61ab1SDavid Howells if (IS_ERR(root))
6659bc61ab1SDavid Howells return PTR_ERR(root);
6669bc61ab1SDavid Howells
6679bc61ab1SDavid Howells sb = root->d_sb;
6689bc61ab1SDavid Howells BUG_ON(!sb);
6699bc61ab1SDavid Howells
6709bc61ab1SDavid Howells fc->root = root;
6719bc61ab1SDavid Howells return 0;
6729bc61ab1SDavid Howells }
6739bc61ab1SDavid Howells
6749bc61ab1SDavid Howells /*
6758d0347f6SDavid Howells * Handle remount.
6768d0347f6SDavid Howells */
legacy_reconfigure(struct fs_context * fc)677f3a09c92SAl Viro static int legacy_reconfigure(struct fs_context *fc)
6788d0347f6SDavid Howells {
6798d0347f6SDavid Howells struct legacy_fs_context *ctx = fc->fs_private;
6808d0347f6SDavid Howells struct super_block *sb = fc->root->d_sb;
6818d0347f6SDavid Howells
6828d0347f6SDavid Howells if (!sb->s_op->remount_fs)
6838d0347f6SDavid Howells return 0;
6848d0347f6SDavid Howells
6858d0347f6SDavid Howells return sb->s_op->remount_fs(sb, &fc->sb_flags,
6868d0347f6SDavid Howells ctx ? ctx->legacy_data : NULL);
6878d0347f6SDavid Howells }
6888d0347f6SDavid Howells
689f3a09c92SAl Viro const struct fs_context_operations legacy_fs_context_ops = {
690f3a09c92SAl Viro .free = legacy_fs_context_free,
6910b52075eSAl Viro .dup = legacy_fs_context_dup,
6923e1aeb00SDavid Howells .parse_param = legacy_parse_param,
693f3a09c92SAl Viro .parse_monolithic = legacy_parse_monolithic,
694f3a09c92SAl Viro .get_tree = legacy_get_tree,
695f3a09c92SAl Viro .reconfigure = legacy_reconfigure,
696f3a09c92SAl Viro };
697f3a09c92SAl Viro
6988d0347f6SDavid Howells /*
6999bc61ab1SDavid Howells * Initialise a legacy context for a filesystem that doesn't support
7009bc61ab1SDavid Howells * fs_context.
7019bc61ab1SDavid Howells */
legacy_init_fs_context(struct fs_context * fc)7029bc61ab1SDavid Howells static int legacy_init_fs_context(struct fs_context *fc)
7039bc61ab1SDavid Howells {
704bb902cb4SYutian Yang fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL_ACCOUNT);
7059bc61ab1SDavid Howells if (!fc->fs_private)
7069bc61ab1SDavid Howells return -ENOMEM;
707f3a09c92SAl Viro fc->ops = &legacy_fs_context_ops;
7089bc61ab1SDavid Howells return 0;
7099bc61ab1SDavid Howells }
7109bc61ab1SDavid Howells
parse_monolithic_mount_data(struct fs_context * fc,void * data)7119bc61ab1SDavid Howells int parse_monolithic_mount_data(struct fs_context *fc, void *data)
7129bc61ab1SDavid Howells {
713f3a09c92SAl Viro int (*monolithic_mount_data)(struct fs_context *, void *);
7143e1aeb00SDavid Howells
715f3a09c92SAl Viro monolithic_mount_data = fc->ops->parse_monolithic;
7163e1aeb00SDavid Howells if (!monolithic_mount_data)
7173e1aeb00SDavid Howells monolithic_mount_data = generic_parse_monolithic;
7183e1aeb00SDavid Howells
719f3a09c92SAl Viro return monolithic_mount_data(fc, data);
7209bc61ab1SDavid Howells }
721ecdab150SDavid Howells
722ecdab150SDavid Howells /*
723ecdab150SDavid Howells * Clean up a context after performing an action on it and put it into a state
724ecdab150SDavid Howells * from where it can be used to reconfigure a superblock.
725ecdab150SDavid Howells *
726ecdab150SDavid Howells * Note that here we do only the parts that can't fail; the rest is in
727ecdab150SDavid Howells * finish_clean_context() below and in between those fs_context is marked
728ecdab150SDavid Howells * FS_CONTEXT_AWAITING_RECONF. The reason for splitup is that after
729ecdab150SDavid Howells * successful mount or remount we need to report success to userland.
730ecdab150SDavid Howells * Trying to do full reinit (for the sake of possible subsequent remount)
731ecdab150SDavid Howells * and failing to allocate memory would've put us into a nasty situation.
732ecdab150SDavid Howells * So here we only discard the old state and reinitialization is left
733ecdab150SDavid Howells * until we actually try to reconfigure.
734ecdab150SDavid Howells */
vfs_clean_context(struct fs_context * fc)735ecdab150SDavid Howells void vfs_clean_context(struct fs_context *fc)
736ecdab150SDavid Howells {
737ecdab150SDavid Howells if (fc->need_free && fc->ops && fc->ops->free)
738ecdab150SDavid Howells fc->ops->free(fc);
739ecdab150SDavid Howells fc->need_free = false;
740ecdab150SDavid Howells fc->fs_private = NULL;
741ecdab150SDavid Howells fc->s_fs_info = NULL;
742ecdab150SDavid Howells fc->sb_flags = 0;
743ecdab150SDavid Howells security_free_mnt_opts(&fc->security);
744ecdab150SDavid Howells kfree(fc->source);
745ecdab150SDavid Howells fc->source = NULL;
74622ed7ecdSChristian Brauner fc->exclusive = false;
747ecdab150SDavid Howells
748ecdab150SDavid Howells fc->purpose = FS_CONTEXT_FOR_RECONFIGURE;
749ecdab150SDavid Howells fc->phase = FS_CONTEXT_AWAITING_RECONF;
750ecdab150SDavid Howells }
751ecdab150SDavid Howells
finish_clean_context(struct fs_context * fc)752ecdab150SDavid Howells int finish_clean_context(struct fs_context *fc)
753ecdab150SDavid Howells {
754ecdab150SDavid Howells int error;
755ecdab150SDavid Howells
756ecdab150SDavid Howells if (fc->phase != FS_CONTEXT_AWAITING_RECONF)
757ecdab150SDavid Howells return 0;
758ecdab150SDavid Howells
759ecdab150SDavid Howells if (fc->fs_type->init_fs_context)
760ecdab150SDavid Howells error = fc->fs_type->init_fs_context(fc);
761ecdab150SDavid Howells else
762ecdab150SDavid Howells error = legacy_init_fs_context(fc);
763ecdab150SDavid Howells if (unlikely(error)) {
764ecdab150SDavid Howells fc->phase = FS_CONTEXT_FAILED;
765ecdab150SDavid Howells return error;
766ecdab150SDavid Howells }
767ecdab150SDavid Howells fc->need_free = true;
768ecdab150SDavid Howells fc->phase = FS_CONTEXT_RECONF_PARAMS;
769ecdab150SDavid Howells return 0;
770ecdab150SDavid Howells }
771