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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /fs/nfs/nfs4super.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/nfs/nfs4super.c')
-rw-r--r-- | fs/nfs/nfs4super.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c new file mode 100644 index 000000000..d09bcfd7d --- /dev/null +++ b/fs/nfs/nfs4super.c @@ -0,0 +1,314 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com> + */ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <linux/nfs4_mount.h> +#include <linux/nfs_fs.h> +#include <linux/nfs_ssc.h> +#include "delegation.h" +#include "internal.h" +#include "nfs4_fs.h" +#include "nfs4idmap.h" +#include "dns_resolve.h" +#include "pnfs.h" +#include "nfs.h" + +#define NFSDBG_FACILITY NFSDBG_VFS + +static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc); +static void nfs4_evict_inode(struct inode *inode); + +static const struct super_operations nfs4_sops = { + .alloc_inode = nfs_alloc_inode, + .free_inode = nfs_free_inode, + .write_inode = nfs4_write_inode, + .drop_inode = nfs_drop_inode, + .statfs = nfs_statfs, + .evict_inode = nfs4_evict_inode, + .umount_begin = nfs_umount_begin, + .show_options = nfs_show_options, + .show_devname = nfs_show_devname, + .show_path = nfs_show_path, + .show_stats = nfs_show_stats, +}; + +struct nfs_subversion nfs_v4 = { + .owner = THIS_MODULE, + .nfs_fs = &nfs4_fs_type, + .rpc_vers = &nfs_version4, + .rpc_ops = &nfs_v4_clientops, + .sops = &nfs4_sops, + .xattr = nfs4_xattr_handlers, +}; + +static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + int ret = nfs_write_inode(inode, wbc); + + if (ret == 0) + ret = pnfs_layoutcommit_inode(inode, + wbc->sync_mode == WB_SYNC_ALL); + return ret; +} + +/* + * Clean out any remaining NFSv4 state that might be left over due + * to open() calls that passed nfs_atomic_lookup, but failed to call + * nfs_open(). + */ +static void nfs4_evict_inode(struct inode *inode) +{ + truncate_inode_pages_final(&inode->i_data); + clear_inode(inode); + /* If we are holding a delegation, return and free it */ + nfs_inode_evict_delegation(inode); + /* Note that above delegreturn would trigger pnfs return-on-close */ + pnfs_return_layout(inode); + pnfs_destroy_layout_final(NFS_I(inode)); + /* First call standard NFS clear_inode() code */ + nfs_clear_inode(inode); + nfs4_xattr_cache_zap(inode); +} + +struct nfs_referral_count { + struct list_head list; + const struct task_struct *task; + unsigned int referral_count; +}; + +static LIST_HEAD(nfs_referral_count_list); +static DEFINE_SPINLOCK(nfs_referral_count_list_lock); + +static struct nfs_referral_count *nfs_find_referral_count(void) +{ + struct nfs_referral_count *p; + + list_for_each_entry(p, &nfs_referral_count_list, list) { + if (p->task == current) + return p; + } + return NULL; +} + +#define NFS_MAX_NESTED_REFERRALS 2 + +static int nfs_referral_loop_protect(void) +{ + struct nfs_referral_count *p, *new; + int ret = -ENOMEM; + + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) + goto out; + new->task = current; + new->referral_count = 1; + + ret = 0; + spin_lock(&nfs_referral_count_list_lock); + p = nfs_find_referral_count(); + if (p != NULL) { + if (p->referral_count >= NFS_MAX_NESTED_REFERRALS) + ret = -ELOOP; + else + p->referral_count++; + } else { + list_add(&new->list, &nfs_referral_count_list); + new = NULL; + } + spin_unlock(&nfs_referral_count_list_lock); + kfree(new); +out: + return ret; +} + +static void nfs_referral_loop_unprotect(void) +{ + struct nfs_referral_count *p; + + spin_lock(&nfs_referral_count_list_lock); + p = nfs_find_referral_count(); + p->referral_count--; + if (p->referral_count == 0) + list_del(&p->list); + else + p = NULL; + spin_unlock(&nfs_referral_count_list_lock); + kfree(p); +} + +static int do_nfs4_mount(struct nfs_server *server, + struct fs_context *fc, + const char *hostname, + const char *export_path) +{ + struct nfs_fs_context *root_ctx; + struct fs_context *root_fc; + struct vfsmount *root_mnt; + struct dentry *dentry; + size_t len; + int ret; + + struct fs_parameter param = { + .key = "source", + .type = fs_value_is_string, + .dirfd = -1, + }; + + if (IS_ERR(server)) + return PTR_ERR(server); + + root_fc = vfs_dup_fs_context(fc); + if (IS_ERR(root_fc)) { + nfs_free_server(server); + return PTR_ERR(root_fc); + } + kfree(root_fc->source); + root_fc->source = NULL; + + root_ctx = nfs_fc2context(root_fc); + root_ctx->internal = true; + root_ctx->server = server; + /* We leave export_path unset as it's not used to find the root. */ + + len = strlen(hostname) + 5; + param.string = kmalloc(len, GFP_KERNEL); + if (param.string == NULL) { + put_fs_context(root_fc); + return -ENOMEM; + } + + /* Does hostname needs to be enclosed in brackets? */ + if (strchr(hostname, ':')) + param.size = snprintf(param.string, len, "[%s]:/", hostname); + else + param.size = snprintf(param.string, len, "%s:/", hostname); + ret = vfs_parse_fs_param(root_fc, ¶m); + kfree(param.string); + if (ret < 0) { + put_fs_context(root_fc); + return ret; + } + root_mnt = fc_mount(root_fc); + put_fs_context(root_fc); + + if (IS_ERR(root_mnt)) + return PTR_ERR(root_mnt); + + ret = nfs_referral_loop_protect(); + if (ret) { + mntput(root_mnt); + return ret; + } + + dentry = mount_subtree(root_mnt, export_path); + nfs_referral_loop_unprotect(); + + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + fc->root = dentry; + return 0; +} + +int nfs4_try_get_tree(struct fs_context *fc) +{ + struct nfs_fs_context *ctx = nfs_fc2context(fc); + int err; + + dfprintk(MOUNT, "--> nfs4_try_get_tree()\n"); + + /* We create a mount for the server's root, walk to the requested + * location and then create another mount for that. + */ + err= do_nfs4_mount(nfs4_create_server(fc), + fc, ctx->nfs_server.hostname, + ctx->nfs_server.export_path); + if (err) { + nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path"); + dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err); + } else { + dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n"); + } + return err; +} + +/* + * Create an NFS4 server record on referral traversal + */ +int nfs4_get_referral_tree(struct fs_context *fc) +{ + struct nfs_fs_context *ctx = nfs_fc2context(fc); + int err; + + dprintk("--> nfs4_referral_mount()\n"); + + /* create a new volume representation */ + err = do_nfs4_mount(nfs4_create_referral_server(fc), + fc, ctx->nfs_server.hostname, + ctx->nfs_server.export_path); + if (err) { + nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path"); + dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", err); + } else { + dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n"); + } + return err; +} + +static int __init init_nfs_v4(void) +{ + int err; + + err = nfs_dns_resolver_init(); + if (err) + goto out; + + err = nfs_idmap_init(); + if (err) + goto out1; + +#ifdef CONFIG_NFS_V4_2 + err = nfs4_xattr_cache_init(); + if (err) + goto out2; +#endif + + err = nfs4_register_sysctl(); + if (err) + goto out2; + +#ifdef CONFIG_NFS_V4_2 + nfs42_ssc_register_ops(); +#endif + register_nfs_version(&nfs_v4); + return 0; +out2: + nfs_idmap_quit(); +out1: + nfs_dns_resolver_destroy(); +out: + return err; +} + +static void __exit exit_nfs_v4(void) +{ + /* Not called in the _init(), conditionally loaded */ + nfs4_pnfs_v3_ds_connect_unload(); + + unregister_nfs_version(&nfs_v4); +#ifdef CONFIG_NFS_V4_2 + nfs4_xattr_cache_exit(); + nfs42_ssc_unregister_ops(); +#endif + nfs4_unregister_sysctl(); + nfs_idmap_quit(); + nfs_dns_resolver_destroy(); +} + +MODULE_LICENSE("GPL"); + +module_init(init_nfs_v4); +module_exit(exit_nfs_v4); |