linux/fs/afs/inode.c
David Howells a74ee0e878
afs: Fix post-setattr file edit to do truncation correctly
At the end of an kAFS RPC operation, there is an "edit" phase (originally
intended for post-directory modification ops to edit the local image) that
the setattr VFS op uses to fix up the pagecache if the RPC that requested
truncation of a file was successful.

afs_setattr_edit_file() calls truncate_setsize() which sets i_size, expands
the pagecache if needed and truncates the pagecache.  The first two of
those, however, are redundant as they've already been done by
afs_setattr_success() under the io_lock and the first is also done under
the callback lock (cb_lock).

Fix afs_setattr_edit_file() to call truncate_pagecache() instead (which is
called by truncate_setsize(), thereby skipping the redundant parts.

Fixes: 100ccd18bb ("netfs: Optimise away reads above the point at which there can be no data")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240823200819.532106-3-dhowells@redhat.com
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Pankaj Raghav <p.raghav@samsung.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-24 16:09:16 +02:00

818 lines
21 KiB
C

/*
* 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"
static const struct inode_operations afs_symlink_inode_operations = {
.get_link = page_get_link,
};
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;
mapping_set_large_folios(inode->i_mapping);
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;
inode->i_mapping->a_ops = &afs_symlink_aops;
} else {
inode->i_mode = S_IFLNK | status->mode;
inode->i_op = &afs_symlink_inode_operations;
inode->i_mapping->a_ops = &afs_symlink_aops;
}
inode_nohighmem(inode);
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;
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) */
atomic64_set(&vnode->cb_expires_at, AFS_NO_CB_PROMISE);
} else {
vnode->cb_server = op->server;
atomic64_set(&vnode->cb_expires_at, vp->scb.callback.expires_at);
}
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)
data_changed = true;
vnode->status = *status;
if (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) {
if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
afs_stat_v(vnode, n_inval);
} 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);
}
}
}
/*
* 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;
atomic64_set(&vnode->cb_expires_at, cb->expires_at);
}
}
/*
* 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 (vnode->netfs.inode.i_state & 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->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->i_state & 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->i_state & 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 generic_delete_inode(inode);
else
return generic_drop_inode(inode);
}
/*
* clear an AFS inode
*/
void afs_evict_inode(struct inode *inode)
{
struct afs_vnode_cache_aux aux;
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);
netfs_wait_for_outstanding_io(inode);
truncate_inode_pages_final(&inode->i_data);
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;
}