/*
 * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
 *
 * This software may be freely redistributed under the terms of the
 * GNU General Public License.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Authors: David Woodhouse <dwmw2@infradead.org>
 *          David Howells <dhowells@redhat.com>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/iversion.h>
#include "internal.h"
#include "afs_fs.h"

void afs_init_new_symlink(struct afs_vnode *vnode, struct afs_operation *op)
{
        size_t size = strlen(op->create.symlink) + 1;
        size_t dsize = 0;
        char *p;

        if (netfs_alloc_folioq_buffer(NULL, &vnode->directory, &dsize, size,
                                      mapping_gfp_mask(vnode->netfs.inode.i_mapping)) < 0)
                return;

        vnode->directory_size = dsize;
        p = kmap_local_folio(folioq_folio(vnode->directory, 0), 0);
        memcpy(p, op->create.symlink, size);
        kunmap_local(p);
        set_bit(AFS_VNODE_DIR_READ, &vnode->flags);
        netfs_single_mark_inode_dirty(&vnode->netfs.inode);
}

static void afs_put_link(void *arg)
{
        struct folio *folio = virt_to_folio(arg);

        kunmap_local(arg);
        folio_put(folio);
}

const char *afs_get_link(struct dentry *dentry, struct inode *inode,
                         struct delayed_call *callback)
{
        struct afs_vnode *vnode = AFS_FS_I(inode);
        struct folio *folio;
        char *content;
        ssize_t ret;

        if (!dentry) {
                /* RCU pathwalk. */
                if (!test_bit(AFS_VNODE_DIR_READ, &vnode->flags) || !afs_check_validity(vnode))
                        return ERR_PTR(-ECHILD);
                goto good;
        }

        if (test_bit(AFS_VNODE_DIR_READ, &vnode->flags))
                goto fetch;

        ret = afs_validate(vnode, NULL);
        if (ret < 0)
                return ERR_PTR(ret);

        if (!test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) &&
            test_bit(AFS_VNODE_DIR_READ, &vnode->flags))
                goto good;

fetch:
        ret = afs_read_single(vnode, NULL);
        if (ret < 0)
                return ERR_PTR(ret);
        set_bit(AFS_VNODE_DIR_READ, &vnode->flags);

good:
        folio = folioq_folio(vnode->directory, 0);
        folio_get(folio);
        content = kmap_local_folio(folio, 0);
        set_delayed_call(callback, afs_put_link, content);
        return content;
}

int afs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
        DEFINE_DELAYED_CALL(done);
        const char *content;
        int len;

        content = afs_get_link(dentry, d_inode(dentry), &done);
        if (IS_ERR(content)) {
                do_delayed_call(&done);
                return PTR_ERR(content);
        }

        len = umin(strlen(content), buflen);
        if (copy_to_user(buffer, content, len))
                len = -EFAULT;
        do_delayed_call(&done);
        return len;
}

static const struct inode_operations afs_symlink_inode_operations = {
        .get_link       = afs_get_link,
        .readlink       = afs_readlink,
};

static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode)
{
        static unsigned long once_only;

        pr_warn("kAFS: AFS vnode with undefined type %u\n", vnode->status.type);
        pr_warn("kAFS: A=%d m=%o s=%llx v=%llx\n",
                vnode->status.abort_code,
                vnode->status.mode,
                vnode->status.size,
                vnode->status.data_version);
        pr_warn("kAFS: vnode %llx:%llx:%x\n",
                vnode->fid.vid,
                vnode->fid.vnode,
                vnode->fid.unique);
        if (parent_vnode)
                pr_warn("kAFS: dir %llx:%llx:%x\n",
                        parent_vnode->fid.vid,
                        parent_vnode->fid.vnode,
                        parent_vnode->fid.unique);

        if (!test_and_set_bit(0, &once_only))
                dump_stack();
}

/*
 * Set parameters for the netfs library
 */
static void afs_set_netfs_context(struct afs_vnode *vnode)
{
        netfs_inode_init(&vnode->netfs, &afs_req_ops, true);
}

/*
 * Initialise an inode from the vnode status.
 */
static int afs_inode_init_from_status(struct afs_operation *op,
                                      struct afs_vnode_param *vp,
                                      struct afs_vnode *vnode)
{
        struct afs_file_status *status = &vp->scb.status;
        struct inode *inode = AFS_VNODE_TO_I(vnode);
        struct timespec64 t;

        _enter("{%llx:%llu.%u} %s",
               vp->fid.vid, vp->fid.vnode, vp->fid.unique,
               op->type ? op->type->name : "???");

        _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
               status->type,
               status->nlink,
               (unsigned long long) status->size,
               status->data_version,
               status->mode);

        write_seqlock(&vnode->cb_lock);

        vnode->cb_v_check = op->cb_v_break;
        vnode->status = *status;

        t = status->mtime_client;
        inode_set_ctime_to_ts(inode, t);
        inode_set_mtime_to_ts(inode, t);
        inode_set_atime_to_ts(inode, t);
        inode->i_flags |= S_NOATIME;
        inode->i_uid = make_kuid(&init_user_ns, status->owner);
        inode->i_gid = make_kgid(&init_user_ns, status->group);
        set_nlink(&vnode->netfs.inode, status->nlink);

        switch (status->type) {
        case AFS_FTYPE_FILE:
                inode->i_mode   = S_IFREG | (status->mode & S_IALLUGO);
                inode->i_op     = &afs_file_inode_operations;
                inode->i_fop    = &afs_file_operations;
                inode->i_mapping->a_ops = &afs_file_aops;
                mapping_set_large_folios(inode->i_mapping);
                break;
        case AFS_FTYPE_DIR:
                inode->i_mode   = S_IFDIR |  (status->mode & S_IALLUGO);
                inode->i_op     = &afs_dir_inode_operations;
                inode->i_fop    = &afs_dir_file_operations;
                inode->i_mapping->a_ops = &afs_dir_aops;
                __set_bit(NETFS_ICTX_SINGLE_NO_UPLOAD, &vnode->netfs.flags);
                /* Assume locally cached directory data will be valid. */
                __set_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
                break;
        case AFS_FTYPE_SYMLINK:
                /* Symlinks with a mode of 0644 are actually mountpoints. */
                if ((status->mode & 0777) == 0644) {
                        inode->i_flags |= S_AUTOMOUNT;

                        set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);

                        inode->i_mode   = S_IFDIR | 0555;
                        inode->i_op     = &afs_mntpt_inode_operations;
                        inode->i_fop    = &afs_mntpt_file_operations;
                } else {
                        inode->i_mode   = S_IFLNK | status->mode;
                        inode->i_op     = &afs_symlink_inode_operations;
                }
                inode->i_mapping->a_ops = &afs_dir_aops;
                inode_nohighmem(inode);
                mapping_set_release_always(inode->i_mapping);
                break;
        default:
                dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
                write_sequnlock(&vnode->cb_lock);
                return afs_protocol_error(NULL, afs_eproto_file_type);
        }

        afs_set_i_size(vnode, status->size);
        afs_set_netfs_context(vnode);

        vnode->invalid_before   = status->data_version;
        trace_afs_set_dv(vnode, status->data_version);
        inode_set_iversion_raw(&vnode->netfs.inode, status->data_version);

        if (!vp->scb.have_cb) {
                /* it's a symlink we just created (the fileserver
                 * didn't give us a callback) */
                afs_clear_cb_promise(vnode, afs_cb_promise_set_new_symlink);
        } else {
                vnode->cb_server = op->server;
                afs_set_cb_promise(vnode, vp->scb.callback.expires_at,
                                   afs_cb_promise_set_new_inode);
        }

        write_sequnlock(&vnode->cb_lock);
        return 0;
}

/*
 * Update the core inode struct from a returned status record.
 */
static void afs_apply_status(struct afs_operation *op,
                             struct afs_vnode_param *vp)
{
        struct afs_file_status *status = &vp->scb.status;
        struct afs_vnode *vnode = vp->vnode;
        struct inode *inode = &vnode->netfs.inode;
        struct timespec64 t;
        umode_t mode;
        bool unexpected_jump = false;
        bool data_changed = false;
        bool change_size = vp->set_size;

        _enter("{%llx:%llu.%u} %s",
               vp->fid.vid, vp->fid.vnode, vp->fid.unique,
               op->type ? op->type->name : "???");

        BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));

        if (status->type != vnode->status.type) {
                pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
                        vnode->fid.vid,
                        vnode->fid.vnode,
                        vnode->fid.unique,
                        status->type, vnode->status.type);
                afs_protocol_error(NULL, afs_eproto_bad_status);
                return;
        }

        if (status->nlink != vnode->status.nlink)
                set_nlink(inode, status->nlink);

        if (status->owner != vnode->status.owner)
                inode->i_uid = make_kuid(&init_user_ns, status->owner);

        if (status->group != vnode->status.group)
                inode->i_gid = make_kgid(&init_user_ns, status->group);

        if (status->mode != vnode->status.mode) {
                mode = inode->i_mode;
                mode &= ~S_IALLUGO;
                mode |= status->mode & S_IALLUGO;
                WRITE_ONCE(inode->i_mode, mode);
        }

        t = status->mtime_client;
        inode_set_mtime_to_ts(inode, t);
        if (vp->update_ctime)
                inode_set_ctime_to_ts(inode, op->ctime);

        if (vnode->status.data_version != status->data_version) {
                trace_afs_set_dv(vnode, status->data_version);
                data_changed = true;
        }

        vnode->status = *status;

        if (vp->dv_before + vp->dv_delta != status->data_version) {
                trace_afs_dv_mismatch(vnode, vp->dv_before, vp->dv_delta,
                                      status->data_version);

                if (vnode->cb_ro_snapshot == atomic_read(&vnode->volume->cb_ro_snapshot) &&
                    atomic64_read(&vnode->cb_expires_at) != AFS_NO_CB_PROMISE)
                        pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
                                vnode->fid.vid, vnode->fid.vnode,
                                (unsigned long long)vp->dv_before + vp->dv_delta,
                                (unsigned long long)status->data_version,
                                op->type ? op->type->name : "???",
                                op->debug_id);

                vnode->invalid_before = status->data_version;
                if (vnode->status.type == AFS_FTYPE_DIR)
                        afs_invalidate_dir(vnode, afs_dir_invalid_dv_mismatch);
                else
                        set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
                change_size = true;
                data_changed = true;
                unexpected_jump = true;
        } else if (vnode->status.type == AFS_FTYPE_DIR) {
                /* Expected directory change is handled elsewhere so
                 * that we can locally edit the directory and save on a
                 * download.
                 */
                if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
                        data_changed = false;
                change_size = true;
        }

        if (data_changed) {
                inode_set_iversion_raw(inode, status->data_version);

                /* Only update the size if the data version jumped.  If the
                 * file is being modified locally, then we might have our own
                 * idea of what the size should be that's not the same as
                 * what's on the server.
                 */
                vnode->netfs.remote_i_size = status->size;
                if (change_size || status->size > i_size_read(inode)) {
                        afs_set_i_size(vnode, status->size);
                        if (unexpected_jump)
                                vnode->netfs.zero_point = status->size;
                        inode_set_ctime_to_ts(inode, t);
                        inode_set_atime_to_ts(inode, t);
                }
                if (op->ops == &afs_fetch_data_operation)
                        op->fetch.subreq->rreq->i_size = status->size;
        }
}

/*
 * Apply a callback to a vnode.
 */
static void afs_apply_callback(struct afs_operation *op,
                               struct afs_vnode_param *vp)
{
        struct afs_callback *cb = &vp->scb.callback;
        struct afs_vnode *vnode = vp->vnode;

        if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
                if (op->volume->type == AFSVL_RWVOL)
                        vnode->cb_server = op->server;
                afs_set_cb_promise(vnode, cb->expires_at, afs_cb_promise_set_apply_cb);
        }
}

/*
 * Apply the received status and callback to an inode all in the same critical
 * section to avoid races with afs_validate().
 */
void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
{
        struct afs_vnode *vnode = vp->vnode;

        _enter("");

        write_seqlock(&vnode->cb_lock);

        if (vp->scb.have_error) {
                /* A YFS server will return this from RemoveFile2 and AFS and
                 * YFS will return this from InlineBulkStatus.
                 */
                if (vp->scb.status.abort_code == VNOVNODE) {
                        set_bit(AFS_VNODE_DELETED, &vnode->flags);
                        clear_nlink(&vnode->netfs.inode);
                        __afs_break_callback(vnode, afs_cb_break_for_deleted);
                        op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
                }
        } else if (vp->scb.have_status) {
                if (vp->speculative &&
                    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
                     vp->dv_before != vnode->status.data_version))
                        /* Ignore the result of a speculative bulk status fetch
                         * if it splits around a modification op, thereby
                         * appearing to regress the data version.
                         */
                        goto out;
                afs_apply_status(op, vp);
                if (vp->scb.have_cb)
                        afs_apply_callback(op, vp);
        } else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
                drop_nlink(&vnode->netfs.inode);
                if (vnode->netfs.inode.i_nlink == 0) {
                        set_bit(AFS_VNODE_DELETED, &vnode->flags);
                        __afs_break_callback(vnode, afs_cb_break_for_deleted);
                }
        }

out:
        write_sequnlock(&vnode->cb_lock);

        if (vp->scb.have_status)
                afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
}

static void afs_fetch_status_success(struct afs_operation *op)
{
        struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
        struct afs_vnode *vnode = vp->vnode;
        int ret;

        if (inode_state_read_once(&vnode->netfs.inode) & I_NEW) {
                ret = afs_inode_init_from_status(op, vp, vnode);
                afs_op_set_error(op, ret);
                if (ret == 0)
                        afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
        } else {
                afs_vnode_commit_status(op, vp);
        }
}

const struct afs_operation_ops afs_fetch_status_operation = {
        .issue_afs_rpc  = afs_fs_fetch_status,
        .issue_yfs_rpc  = yfs_fs_fetch_status,
        .success        = afs_fetch_status_success,
        .aborted        = afs_check_for_remote_deletion,
};

/*
 * Fetch file status from the volume.
 */
int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
                     afs_access_t *_caller_access)
{
        struct afs_operation *op;

        _enter("%s,{%llx:%llu.%u,S=%lx}",
               vnode->volume->name,
               vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
               vnode->flags);

        op = afs_alloc_operation(key, vnode->volume);
        if (IS_ERR(op))
                return PTR_ERR(op);

        afs_op_set_vnode(op, 0, vnode);

        op->nr_files    = 1;
        op->ops         = &afs_fetch_status_operation;
        afs_begin_vnode_operation(op);
        afs_wait_for_operation(op);

        if (_caller_access)
                *_caller_access = op->file[0].scb.status.caller_access;
        return afs_put_operation(op);
}

/*
 * ilookup() comparator
 */
int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
{
        struct afs_vnode *vnode = AFS_FS_I(inode);
        struct afs_fid *fid = opaque;

        return (fid->vnode == vnode->fid.vnode &&
                fid->vnode_hi == vnode->fid.vnode_hi &&
                fid->unique == vnode->fid.unique);
}

/*
 * iget5() comparator
 */
static int afs_iget5_test(struct inode *inode, void *opaque)
{
        struct afs_vnode_param *vp = opaque;
        //struct afs_vnode *vnode = AFS_FS_I(inode);

        return afs_ilookup5_test_by_fid(inode, &vp->fid);
}

/*
 * iget5() inode initialiser
 */
static int afs_iget5_set(struct inode *inode, void *opaque)
{
        struct afs_vnode_param *vp = opaque;
        struct afs_super_info *as = AFS_FS_S(inode->i_sb);
        struct afs_vnode *vnode = AFS_FS_I(inode);

        vnode->volume           = as->volume;
        vnode->fid              = vp->fid;

        /* YFS supports 96-bit vnode IDs, but Linux only supports
         * 64-bit inode numbers.
         */
        inode->i_ino            = vnode->fid.vnode;
        inode->i_generation     = vnode->fid.unique;
        return 0;
}

/*
 * Get a cache cookie for an inode.
 */
static void afs_get_inode_cache(struct afs_vnode *vnode)
{
#ifdef CONFIG_AFS_FSCACHE
        struct {
                __be32 vnode_id;
                __be32 unique;
                __be32 vnode_id_ext[2]; /* Allow for a 96-bit key */
        } __packed key;
        struct afs_vnode_cache_aux aux;

        if (vnode->status.type != AFS_FTYPE_FILE &&
            vnode->status.type != AFS_FTYPE_DIR &&
            vnode->status.type != AFS_FTYPE_SYMLINK) {
                vnode->netfs.cache = NULL;
                return;
        }

        key.vnode_id            = htonl(vnode->fid.vnode);
        key.unique              = htonl(vnode->fid.unique);
        key.vnode_id_ext[0]     = htonl(vnode->fid.vnode >> 32);
        key.vnode_id_ext[1]     = htonl(vnode->fid.vnode_hi);
        afs_set_cache_aux(vnode, &aux);

        afs_vnode_set_cache(vnode,
                            fscache_acquire_cookie(
                                    vnode->volume->cache,
                                    vnode->status.type == AFS_FTYPE_FILE ?
                                    0 : FSCACHE_ADV_SINGLE_CHUNK,
                                    &key, sizeof(key),
                                    &aux, sizeof(aux),
                                    i_size_read(&vnode->netfs.inode)));
#endif
}

/*
 * inode retrieval
 */
struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
{
        struct afs_vnode_param *dvp = &op->file[0];
        struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
        struct afs_vnode *vnode;
        struct inode *inode;
        int ret;

        _enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);

        inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
        if (!inode) {
                _leave(" = -ENOMEM");
                return ERR_PTR(-ENOMEM);
        }

        vnode = AFS_FS_I(inode);

        _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
               inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);

        /* deal with an existing inode */
        if (!(inode_state_read_once(inode) & I_NEW)) {
                _leave(" = %p", inode);
                return inode;
        }

        ret = afs_inode_init_from_status(op, vp, vnode);
        if (ret < 0)
                goto bad_inode;

        afs_get_inode_cache(vnode);

        /* success */
        clear_bit(AFS_VNODE_UNSET, &vnode->flags);
        unlock_new_inode(inode);
        _leave(" = %p", inode);
        return inode;

        /* failure */
bad_inode:
        iget_failed(inode);
        _leave(" = %d [bad]", ret);
        return ERR_PTR(ret);
}

static int afs_iget5_set_root(struct inode *inode, void *opaque)
{
        struct afs_super_info *as = AFS_FS_S(inode->i_sb);
        struct afs_vnode *vnode = AFS_FS_I(inode);

        vnode->volume           = as->volume;
        vnode->fid.vid          = as->volume->vid;
        vnode->fid.vnode        = 1;
        vnode->fid.unique       = 1;
        inode->i_ino            = 1;
        inode->i_generation     = 1;
        return 0;
}

/*
 * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
 * the volume.
 */
struct inode *afs_root_iget(struct super_block *sb, struct key *key)
{
        struct afs_super_info *as = AFS_FS_S(sb);
        struct afs_operation *op;
        struct afs_vnode *vnode;
        struct inode *inode;
        int ret;

        _enter(",{%llx},,", as->volume->vid);

        inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
        if (!inode) {
                _leave(" = -ENOMEM");
                return ERR_PTR(-ENOMEM);
        }

        _debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);

        BUG_ON(!(inode_state_read_once(inode) & I_NEW));

        vnode = AFS_FS_I(inode);
        vnode->cb_v_check = atomic_read(&as->volume->cb_v_break);
        afs_set_netfs_context(vnode);

        op = afs_alloc_operation(key, as->volume);
        if (IS_ERR(op)) {
                ret = PTR_ERR(op);
                goto error;
        }

        afs_op_set_vnode(op, 0, vnode);

        op->nr_files    = 1;
        op->ops         = &afs_fetch_status_operation;
        ret = afs_do_sync_operation(op);
        if (ret < 0)
                goto error;

        afs_get_inode_cache(vnode);

        clear_bit(AFS_VNODE_UNSET, &vnode->flags);
        unlock_new_inode(inode);
        _leave(" = %p", inode);
        return inode;

error:
        iget_failed(inode);
        _leave(" = %d [bad]", ret);
        return ERR_PTR(ret);
}

/*
 * read the attributes of an inode
 */
int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
                struct kstat *stat, u32 request_mask, unsigned int query_flags)
{
        struct inode *inode = d_inode(path->dentry);
        struct afs_vnode *vnode = AFS_FS_I(inode);
        struct key *key;
        int ret, seq;

        _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);

        if (vnode->volume &&
            !(query_flags & AT_STATX_DONT_SYNC) &&
            atomic64_read(&vnode->cb_expires_at) == AFS_NO_CB_PROMISE) {
                key = afs_request_key(vnode->volume->cell);
                if (IS_ERR(key))
                        return PTR_ERR(key);
                ret = afs_validate(vnode, key);
                key_put(key);
                if (ret < 0)
                        return ret;
        }

        do {
                seq = read_seqbegin(&vnode->cb_lock);
                generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
                if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
                    stat->nlink > 0)
                        stat->nlink -= 1;

                /* Lie about the size of directories.  We maintain a locally
                 * edited copy and may make different allocation decisions on
                 * it, but we need to give userspace the server's size.
                 */
                if (S_ISDIR(inode->i_mode))
                        stat->size = vnode->netfs.remote_i_size;
        } while (read_seqretry(&vnode->cb_lock, seq));

        return 0;
}

/*
 * discard an AFS inode
 */
int afs_drop_inode(struct inode *inode)
{
        _enter("");

        if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
                return inode_just_drop(inode);
        else
                return inode_generic_drop(inode);
}

/*
 * clear an AFS inode
 */
void afs_evict_inode(struct inode *inode)
{
        struct afs_vnode_cache_aux aux;
        struct afs_super_info *sbi = AFS_FS_S(inode->i_sb);
        struct afs_vnode *vnode = AFS_FS_I(inode);

        _enter("{%llx:%llu.%d}",
               vnode->fid.vid,
               vnode->fid.vnode,
               vnode->fid.unique);

        _debug("CLEAR INODE %p", inode);

        ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);

        if ((S_ISDIR(inode->i_mode) ||
             S_ISLNK(inode->i_mode)) &&
            (inode_state_read_once(inode) & I_DIRTY) &&
            !sbi->dyn_root) {
                struct writeback_control wbc = {
                        .sync_mode = WB_SYNC_ALL,
                        .for_sync = true,
                        .range_end = LLONG_MAX,
                };

                afs_single_writepages(inode->i_mapping, &wbc);
        }

        netfs_wait_for_outstanding_io(inode);
        truncate_inode_pages_final(&inode->i_data);
        netfs_free_folioq_buffer(vnode->directory);

        afs_set_cache_aux(vnode, &aux);
        netfs_clear_inode_writeback(inode, &aux);
        clear_inode(inode);

        while (!list_empty(&vnode->wb_keys)) {
                struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
                                                    struct afs_wb_key, vnode_link);
                list_del(&wbk->vnode_link);
                afs_put_wb_key(wbk);
        }

        fscache_relinquish_cookie(afs_vnode_cache(vnode),
                                  test_bit(AFS_VNODE_DELETED, &vnode->flags));

        afs_prune_wb_keys(vnode);
        afs_put_permits(rcu_access_pointer(vnode->permit_cache));
        key_put(vnode->silly_key);
        vnode->silly_key = NULL;
        key_put(vnode->lock_key);
        vnode->lock_key = NULL;
        _leave("");
}

static void afs_setattr_success(struct afs_operation *op)
{
        struct afs_vnode_param *vp = &op->file[0];
        struct inode *inode = &vp->vnode->netfs.inode;
        loff_t old_i_size = i_size_read(inode);

        op->setattr.old_i_size = old_i_size;
        afs_vnode_commit_status(op, vp);
        /* inode->i_size has now been changed. */

        if (op->setattr.attr->ia_valid & ATTR_SIZE) {
                loff_t size = op->setattr.attr->ia_size;
                if (size > old_i_size)
                        pagecache_isize_extended(inode, old_i_size, size);
        }
}

static void afs_setattr_edit_file(struct afs_operation *op)
{
        struct afs_vnode_param *vp = &op->file[0];
        struct afs_vnode *vnode = vp->vnode;
        struct inode *inode = &vnode->netfs.inode;

        if (op->setattr.attr->ia_valid & ATTR_SIZE) {
                loff_t size = op->setattr.attr->ia_size;
                loff_t old = op->setattr.old_i_size;

                /* Note: inode->i_size was updated by afs_apply_status() inside
                 * the I/O and callback locks.
                 */

                if (size != old) {
                        truncate_pagecache(inode, size);
                        netfs_resize_file(&vnode->netfs, size, true);
                        fscache_resize_cookie(afs_vnode_cache(vnode), size);
                }
        }
}

static const struct afs_operation_ops afs_setattr_operation = {
        .issue_afs_rpc  = afs_fs_setattr,
        .issue_yfs_rpc  = yfs_fs_setattr,
        .success        = afs_setattr_success,
        .edit_dir       = afs_setattr_edit_file,
};

/*
 * set the attributes of an inode
 */
int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                struct iattr *attr)
{
        const unsigned int supported =
                ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
                ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
        struct afs_operation *op;
        struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
        struct inode *inode = &vnode->netfs.inode;
        loff_t i_size;
        int ret;

        _enter("{%llx:%llu},{n=%pd},%x",
               vnode->fid.vid, vnode->fid.vnode, dentry,
               attr->ia_valid);

        if (!(attr->ia_valid & supported)) {
                _leave(" = 0 [unsupported]");
                return 0;
        }

        i_size = i_size_read(inode);
        if (attr->ia_valid & ATTR_SIZE) {
                if (!S_ISREG(inode->i_mode))
                        return -EISDIR;

                ret = inode_newsize_ok(inode, attr->ia_size);
                if (ret)
                        return ret;

                if (attr->ia_size == i_size)
                        attr->ia_valid &= ~ATTR_SIZE;
        }

        fscache_use_cookie(afs_vnode_cache(vnode), true);

        /* Prevent any new writebacks from starting whilst we do this. */
        down_write(&vnode->validate_lock);

        if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
                loff_t size = attr->ia_size;

                /* Wait for any outstanding writes to the server to complete */
                loff_t from = min(size, i_size);
                loff_t to = max(size, i_size);
                ret = filemap_fdatawait_range(inode->i_mapping, from, to);
                if (ret < 0)
                        goto out_unlock;

                /* Don't talk to the server if we're just shortening in-memory
                 * writes that haven't gone to the server yet.
                 */
                if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
                    attr->ia_size < i_size &&
                    attr->ia_size > vnode->netfs.remote_i_size) {
                        truncate_setsize(inode, attr->ia_size);
                        netfs_resize_file(&vnode->netfs, size, false);
                        fscache_resize_cookie(afs_vnode_cache(vnode),
                                              attr->ia_size);
                        ret = 0;
                        goto out_unlock;
                }
        }

        op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
                                  afs_file_key(attr->ia_file) : NULL),
                                 vnode->volume);
        if (IS_ERR(op)) {
                ret = PTR_ERR(op);
                goto out_unlock;
        }

        afs_op_set_vnode(op, 0, vnode);
        op->setattr.attr = attr;

        if (attr->ia_valid & ATTR_SIZE) {
                op->file[0].dv_delta = 1;
                op->file[0].set_size = true;
        }
        op->ctime = attr->ia_ctime;
        op->file[0].update_ctime = 1;
        op->file[0].modification = true;

        op->ops = &afs_setattr_operation;
        ret = afs_do_sync_operation(op);

out_unlock:
        up_write(&vnode->validate_lock);
        fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
        _leave(" = %d", ret);
        return ret;
}