mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
504 lines
12 KiB
504 lines
12 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* AFS filesystem file handling |
|
* |
|
* Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. |
|
* Written by David Howells ([email protected]) |
|
*/ |
|
|
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/init.h> |
|
#include <linux/fs.h> |
|
#include <linux/pagemap.h> |
|
#include <linux/writeback.h> |
|
#include <linux/gfp.h> |
|
#include <linux/task_io_accounting_ops.h> |
|
#include <linux/mm.h> |
|
#include <linux/netfs.h> |
|
#include "internal.h" |
|
|
|
static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); |
|
static int afs_readpage(struct file *file, struct page *page); |
|
static void afs_invalidatepage(struct page *page, unsigned int offset, |
|
unsigned int length); |
|
static int afs_releasepage(struct page *page, gfp_t gfp_flags); |
|
|
|
static void afs_readahead(struct readahead_control *ractl); |
|
|
|
const struct file_operations afs_file_operations = { |
|
.open = afs_open, |
|
.release = afs_release, |
|
.llseek = generic_file_llseek, |
|
.read_iter = generic_file_read_iter, |
|
.write_iter = afs_file_write, |
|
.mmap = afs_file_mmap, |
|
.splice_read = generic_file_splice_read, |
|
.splice_write = iter_file_splice_write, |
|
.fsync = afs_fsync, |
|
.lock = afs_lock, |
|
.flock = afs_flock, |
|
}; |
|
|
|
const struct inode_operations afs_file_inode_operations = { |
|
.getattr = afs_getattr, |
|
.setattr = afs_setattr, |
|
.permission = afs_permission, |
|
}; |
|
|
|
const struct address_space_operations afs_fs_aops = { |
|
.readpage = afs_readpage, |
|
.readahead = afs_readahead, |
|
.set_page_dirty = afs_set_page_dirty, |
|
.launder_page = afs_launder_page, |
|
.releasepage = afs_releasepage, |
|
.invalidatepage = afs_invalidatepage, |
|
.write_begin = afs_write_begin, |
|
.write_end = afs_write_end, |
|
.writepage = afs_writepage, |
|
.writepages = afs_writepages, |
|
}; |
|
|
|
static const struct vm_operations_struct afs_vm_ops = { |
|
.fault = filemap_fault, |
|
.map_pages = filemap_map_pages, |
|
.page_mkwrite = afs_page_mkwrite, |
|
}; |
|
|
|
/* |
|
* Discard a pin on a writeback key. |
|
*/ |
|
void afs_put_wb_key(struct afs_wb_key *wbk) |
|
{ |
|
if (wbk && refcount_dec_and_test(&wbk->usage)) { |
|
key_put(wbk->key); |
|
kfree(wbk); |
|
} |
|
} |
|
|
|
/* |
|
* Cache key for writeback. |
|
*/ |
|
int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) |
|
{ |
|
struct afs_wb_key *wbk, *p; |
|
|
|
wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); |
|
if (!wbk) |
|
return -ENOMEM; |
|
refcount_set(&wbk->usage, 2); |
|
wbk->key = af->key; |
|
|
|
spin_lock(&vnode->wb_lock); |
|
list_for_each_entry(p, &vnode->wb_keys, vnode_link) { |
|
if (p->key == wbk->key) |
|
goto found; |
|
} |
|
|
|
key_get(wbk->key); |
|
list_add_tail(&wbk->vnode_link, &vnode->wb_keys); |
|
spin_unlock(&vnode->wb_lock); |
|
af->wb = wbk; |
|
return 0; |
|
|
|
found: |
|
refcount_inc(&p->usage); |
|
spin_unlock(&vnode->wb_lock); |
|
af->wb = p; |
|
kfree(wbk); |
|
return 0; |
|
} |
|
|
|
/* |
|
* open an AFS file or directory and attach a key to it |
|
*/ |
|
int afs_open(struct inode *inode, struct file *file) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(inode); |
|
struct afs_file *af; |
|
struct key *key; |
|
int ret; |
|
|
|
_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
|
|
|
key = afs_request_key(vnode->volume->cell); |
|
if (IS_ERR(key)) { |
|
ret = PTR_ERR(key); |
|
goto error; |
|
} |
|
|
|
af = kzalloc(sizeof(*af), GFP_KERNEL); |
|
if (!af) { |
|
ret = -ENOMEM; |
|
goto error_key; |
|
} |
|
af->key = key; |
|
|
|
ret = afs_validate(vnode, key); |
|
if (ret < 0) |
|
goto error_af; |
|
|
|
if (file->f_mode & FMODE_WRITE) { |
|
ret = afs_cache_wb_key(vnode, af); |
|
if (ret < 0) |
|
goto error_af; |
|
} |
|
|
|
if (file->f_flags & O_TRUNC) |
|
set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); |
|
|
|
file->private_data = af; |
|
_leave(" = 0"); |
|
return 0; |
|
|
|
error_af: |
|
kfree(af); |
|
error_key: |
|
key_put(key); |
|
error: |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* release an AFS file or directory and discard its key |
|
*/ |
|
int afs_release(struct inode *inode, struct file *file) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(inode); |
|
struct afs_file *af = file->private_data; |
|
int ret = 0; |
|
|
|
_enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); |
|
|
|
if ((file->f_mode & FMODE_WRITE)) |
|
ret = vfs_fsync(file, 0); |
|
|
|
file->private_data = NULL; |
|
if (af->wb) |
|
afs_put_wb_key(af->wb); |
|
key_put(af->key); |
|
kfree(af); |
|
afs_prune_wb_keys(vnode); |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Allocate a new read record. |
|
*/ |
|
struct afs_read *afs_alloc_read(gfp_t gfp) |
|
{ |
|
struct afs_read *req; |
|
|
|
req = kzalloc(sizeof(struct afs_read), gfp); |
|
if (req) |
|
refcount_set(&req->usage, 1); |
|
|
|
return req; |
|
} |
|
|
|
/* |
|
* Dispose of a ref to a read record. |
|
*/ |
|
void afs_put_read(struct afs_read *req) |
|
{ |
|
if (refcount_dec_and_test(&req->usage)) { |
|
if (req->cleanup) |
|
req->cleanup(req); |
|
key_put(req->key); |
|
kfree(req); |
|
} |
|
} |
|
|
|
static void afs_fetch_data_notify(struct afs_operation *op) |
|
{ |
|
struct afs_read *req = op->fetch.req; |
|
struct netfs_read_subrequest *subreq = req->subreq; |
|
int error = op->error; |
|
|
|
if (error == -ECONNABORTED) |
|
error = afs_abort_to_error(op->ac.abort_code); |
|
req->error = error; |
|
|
|
if (subreq) { |
|
__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); |
|
netfs_subreq_terminated(subreq, error ?: req->actual_len, false); |
|
req->subreq = NULL; |
|
} else if (req->done) { |
|
req->done(req); |
|
} |
|
} |
|
|
|
static void afs_fetch_data_success(struct afs_operation *op) |
|
{ |
|
struct afs_vnode *vnode = op->file[0].vnode; |
|
|
|
_enter("op=%08x", op->debug_id); |
|
afs_vnode_commit_status(op, &op->file[0]); |
|
afs_stat_v(vnode, n_fetches); |
|
atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes); |
|
afs_fetch_data_notify(op); |
|
} |
|
|
|
static void afs_fetch_data_put(struct afs_operation *op) |
|
{ |
|
op->fetch.req->error = op->error; |
|
afs_put_read(op->fetch.req); |
|
} |
|
|
|
static const struct afs_operation_ops afs_fetch_data_operation = { |
|
.issue_afs_rpc = afs_fs_fetch_data, |
|
.issue_yfs_rpc = yfs_fs_fetch_data, |
|
.success = afs_fetch_data_success, |
|
.aborted = afs_check_for_remote_deletion, |
|
.failed = afs_fetch_data_notify, |
|
.put = afs_fetch_data_put, |
|
}; |
|
|
|
/* |
|
* Fetch file data from the volume. |
|
*/ |
|
int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req) |
|
{ |
|
struct afs_operation *op; |
|
|
|
_enter("%s{%llx:%llu.%u},%x,,,", |
|
vnode->volume->name, |
|
vnode->fid.vid, |
|
vnode->fid.vnode, |
|
vnode->fid.unique, |
|
key_serial(req->key)); |
|
|
|
op = afs_alloc_operation(req->key, vnode->volume); |
|
if (IS_ERR(op)) { |
|
if (req->subreq) |
|
netfs_subreq_terminated(req->subreq, PTR_ERR(op), false); |
|
return PTR_ERR(op); |
|
} |
|
|
|
afs_op_set_vnode(op, 0, vnode); |
|
|
|
op->fetch.req = afs_get_read(req); |
|
op->ops = &afs_fetch_data_operation; |
|
return afs_do_sync_operation(op); |
|
} |
|
|
|
static void afs_req_issue_op(struct netfs_read_subrequest *subreq) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode); |
|
struct afs_read *fsreq; |
|
|
|
fsreq = afs_alloc_read(GFP_NOFS); |
|
if (!fsreq) |
|
return netfs_subreq_terminated(subreq, -ENOMEM, false); |
|
|
|
fsreq->subreq = subreq; |
|
fsreq->pos = subreq->start + subreq->transferred; |
|
fsreq->len = subreq->len - subreq->transferred; |
|
fsreq->key = subreq->rreq->netfs_priv; |
|
fsreq->vnode = vnode; |
|
fsreq->iter = &fsreq->def_iter; |
|
|
|
iov_iter_xarray(&fsreq->def_iter, READ, |
|
&fsreq->vnode->vfs_inode.i_mapping->i_pages, |
|
fsreq->pos, fsreq->len); |
|
|
|
afs_fetch_data(fsreq->vnode, fsreq); |
|
} |
|
|
|
static int afs_symlink_readpage(struct page *page) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
|
struct afs_read *fsreq; |
|
int ret; |
|
|
|
fsreq = afs_alloc_read(GFP_NOFS); |
|
if (!fsreq) |
|
return -ENOMEM; |
|
|
|
fsreq->pos = page->index * PAGE_SIZE; |
|
fsreq->len = PAGE_SIZE; |
|
fsreq->vnode = vnode; |
|
fsreq->iter = &fsreq->def_iter; |
|
iov_iter_xarray(&fsreq->def_iter, READ, &page->mapping->i_pages, |
|
fsreq->pos, fsreq->len); |
|
|
|
ret = afs_fetch_data(fsreq->vnode, fsreq); |
|
page_endio(page, false, ret); |
|
return ret; |
|
} |
|
|
|
static void afs_init_rreq(struct netfs_read_request *rreq, struct file *file) |
|
{ |
|
rreq->netfs_priv = key_get(afs_file_key(file)); |
|
} |
|
|
|
static bool afs_is_cache_enabled(struct inode *inode) |
|
{ |
|
struct fscache_cookie *cookie = afs_vnode_cache(AFS_FS_I(inode)); |
|
|
|
return fscache_cookie_enabled(cookie) && !hlist_empty(&cookie->backing_objects); |
|
} |
|
|
|
static int afs_begin_cache_operation(struct netfs_read_request *rreq) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(rreq->inode); |
|
|
|
return fscache_begin_read_operation(rreq, afs_vnode_cache(vnode)); |
|
} |
|
|
|
static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len, |
|
struct page *page, void **_fsdata) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
|
|
|
return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0; |
|
} |
|
|
|
static void afs_priv_cleanup(struct address_space *mapping, void *netfs_priv) |
|
{ |
|
key_put(netfs_priv); |
|
} |
|
|
|
const struct netfs_read_request_ops afs_req_ops = { |
|
.init_rreq = afs_init_rreq, |
|
.is_cache_enabled = afs_is_cache_enabled, |
|
.begin_cache_operation = afs_begin_cache_operation, |
|
.check_write_begin = afs_check_write_begin, |
|
.issue_op = afs_req_issue_op, |
|
.cleanup = afs_priv_cleanup, |
|
}; |
|
|
|
static int afs_readpage(struct file *file, struct page *page) |
|
{ |
|
if (!file) |
|
return afs_symlink_readpage(page); |
|
|
|
return netfs_readpage(file, page, &afs_req_ops, NULL); |
|
} |
|
|
|
static void afs_readahead(struct readahead_control *ractl) |
|
{ |
|
netfs_readahead(ractl, &afs_req_ops, NULL); |
|
} |
|
|
|
/* |
|
* Adjust the dirty region of the page on truncation or full invalidation, |
|
* getting rid of the markers altogether if the region is entirely invalidated. |
|
*/ |
|
static void afs_invalidate_dirty(struct page *page, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
|
unsigned long priv; |
|
unsigned int f, t, end = offset + length; |
|
|
|
priv = page_private(page); |
|
|
|
/* we clean up only if the entire page is being invalidated */ |
|
if (offset == 0 && length == thp_size(page)) |
|
goto full_invalidate; |
|
|
|
/* If the page was dirtied by page_mkwrite(), the PTE stays writable |
|
* and we don't get another notification to tell us to expand it |
|
* again. |
|
*/ |
|
if (afs_is_page_dirty_mmapped(priv)) |
|
return; |
|
|
|
/* We may need to shorten the dirty region */ |
|
f = afs_page_dirty_from(page, priv); |
|
t = afs_page_dirty_to(page, priv); |
|
|
|
if (t <= offset || f >= end) |
|
return; /* Doesn't overlap */ |
|
|
|
if (f < offset && t > end) |
|
return; /* Splits the dirty region - just absorb it */ |
|
|
|
if (f >= offset && t <= end) |
|
goto undirty; |
|
|
|
if (f < offset) |
|
t = offset; |
|
else |
|
f = end; |
|
if (f == t) |
|
goto undirty; |
|
|
|
priv = afs_page_dirty(page, f, t); |
|
set_page_private(page, priv); |
|
trace_afs_page_dirty(vnode, tracepoint_string("trunc"), page); |
|
return; |
|
|
|
undirty: |
|
trace_afs_page_dirty(vnode, tracepoint_string("undirty"), page); |
|
clear_page_dirty_for_io(page); |
|
full_invalidate: |
|
trace_afs_page_dirty(vnode, tracepoint_string("inval"), page); |
|
detach_page_private(page); |
|
} |
|
|
|
/* |
|
* invalidate part or all of a page |
|
* - release a page and clean up its private data if offset is 0 (indicating |
|
* the entire page) |
|
*/ |
|
static void afs_invalidatepage(struct page *page, unsigned int offset, |
|
unsigned int length) |
|
{ |
|
_enter("{%lu},%u,%u", page->index, offset, length); |
|
|
|
BUG_ON(!PageLocked(page)); |
|
|
|
if (PagePrivate(page)) |
|
afs_invalidate_dirty(page, offset, length); |
|
|
|
wait_on_page_fscache(page); |
|
_leave(""); |
|
} |
|
|
|
/* |
|
* release a page and clean up its private state if it's not busy |
|
* - return true if the page can now be released, false if not |
|
*/ |
|
static int afs_releasepage(struct page *page, gfp_t gfp_flags) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
|
|
|
_enter("{{%llx:%llu}[%lu],%lx},%x", |
|
vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, |
|
gfp_flags); |
|
|
|
/* deny if page is being written to the cache and the caller hasn't |
|
* elected to wait */ |
|
#ifdef CONFIG_AFS_FSCACHE |
|
if (PageFsCache(page)) { |
|
if (!(gfp_flags & __GFP_DIRECT_RECLAIM) || !(gfp_flags & __GFP_FS)) |
|
return false; |
|
wait_on_page_fscache(page); |
|
} |
|
#endif |
|
|
|
if (PagePrivate(page)) { |
|
trace_afs_page_dirty(vnode, tracepoint_string("rel"), page); |
|
detach_page_private(page); |
|
} |
|
|
|
/* indicate that the page can be released */ |
|
_leave(" = T"); |
|
return 1; |
|
} |
|
|
|
/* |
|
* Handle setting up a memory mapping on an AFS file. |
|
*/ |
|
static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) |
|
{ |
|
int ret; |
|
|
|
ret = generic_file_mmap(file, vma); |
|
if (ret == 0) |
|
vma->vm_ops = &afs_vm_ops; |
|
return ret; |
|
}
|
|
|