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947 lines
22 KiB
947 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* handling of writes to regular files and writing back to the server |
|
* |
|
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
|
* Written by David Howells ([email protected]) |
|
*/ |
|
|
|
#include <linux/backing-dev.h> |
|
#include <linux/slab.h> |
|
#include <linux/fs.h> |
|
#include <linux/pagemap.h> |
|
#include <linux/writeback.h> |
|
#include <linux/pagevec.h> |
|
#include "internal.h" |
|
|
|
/* |
|
* mark a page as having been made dirty and thus needing writeback |
|
*/ |
|
int afs_set_page_dirty(struct page *page) |
|
{ |
|
_enter(""); |
|
return __set_page_dirty_nobuffers(page); |
|
} |
|
|
|
/* |
|
* partly or wholly fill a page that's under preparation for writing |
|
*/ |
|
static int afs_fill_page(struct afs_vnode *vnode, struct key *key, |
|
loff_t pos, unsigned int len, struct page *page) |
|
{ |
|
struct afs_read *req; |
|
size_t p; |
|
void *data; |
|
int ret; |
|
|
|
_enter(",,%llu", (unsigned long long)pos); |
|
|
|
if (pos >= vnode->vfs_inode.i_size) { |
|
p = pos & ~PAGE_MASK; |
|
ASSERTCMP(p + len, <=, PAGE_SIZE); |
|
data = kmap(page); |
|
memset(data + p, 0, len); |
|
kunmap(page); |
|
return 0; |
|
} |
|
|
|
req = kzalloc(struct_size(req, array, 1), GFP_KERNEL); |
|
if (!req) |
|
return -ENOMEM; |
|
|
|
refcount_set(&req->usage, 1); |
|
req->pos = pos; |
|
req->len = len; |
|
req->nr_pages = 1; |
|
req->pages = req->array; |
|
req->pages[0] = page; |
|
get_page(page); |
|
|
|
ret = afs_fetch_data(vnode, key, req); |
|
afs_put_read(req); |
|
if (ret < 0) { |
|
if (ret == -ENOENT) { |
|
_debug("got NOENT from server" |
|
" - marking file deleted and stale"); |
|
set_bit(AFS_VNODE_DELETED, &vnode->flags); |
|
ret = -ESTALE; |
|
} |
|
} |
|
|
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* prepare to perform part of a write to a page |
|
*/ |
|
int afs_write_begin(struct file *file, struct address_space *mapping, |
|
loff_t pos, unsigned len, unsigned flags, |
|
struct page **_page, void **fsdata) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
|
struct page *page; |
|
struct key *key = afs_file_key(file); |
|
unsigned long priv; |
|
unsigned f, from = pos & (PAGE_SIZE - 1); |
|
unsigned t, to = from + len; |
|
pgoff_t index = pos >> PAGE_SHIFT; |
|
int ret; |
|
|
|
_enter("{%llx:%llu},{%lx},%u,%u", |
|
vnode->fid.vid, vnode->fid.vnode, index, from, to); |
|
|
|
page = grab_cache_page_write_begin(mapping, index, flags); |
|
if (!page) |
|
return -ENOMEM; |
|
|
|
if (!PageUptodate(page) && len != PAGE_SIZE) { |
|
ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page); |
|
if (ret < 0) { |
|
unlock_page(page); |
|
put_page(page); |
|
_leave(" = %d [prep]", ret); |
|
return ret; |
|
} |
|
SetPageUptodate(page); |
|
} |
|
|
|
try_again: |
|
/* See if this page is already partially written in a way that we can |
|
* merge the new write with. |
|
*/ |
|
t = f = 0; |
|
if (PagePrivate(page)) { |
|
priv = page_private(page); |
|
f = afs_page_dirty_from(priv); |
|
t = afs_page_dirty_to(priv); |
|
ASSERTCMP(f, <=, t); |
|
} |
|
|
|
if (f != t) { |
|
if (PageWriteback(page)) { |
|
trace_afs_page_dirty(vnode, tracepoint_string("alrdy"), |
|
page->index, priv); |
|
goto flush_conflicting_write; |
|
} |
|
/* If the file is being filled locally, allow inter-write |
|
* spaces to be merged into writes. If it's not, only write |
|
* back what the user gives us. |
|
*/ |
|
if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) && |
|
(to < f || from > t)) |
|
goto flush_conflicting_write; |
|
} |
|
|
|
*_page = page; |
|
_leave(" = 0"); |
|
return 0; |
|
|
|
/* The previous write and this write aren't adjacent or overlapping, so |
|
* flush the page out. |
|
*/ |
|
flush_conflicting_write: |
|
_debug("flush conflict"); |
|
ret = write_one_page(page); |
|
if (ret < 0) |
|
goto error; |
|
|
|
ret = lock_page_killable(page); |
|
if (ret < 0) |
|
goto error; |
|
goto try_again; |
|
|
|
error: |
|
put_page(page); |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* finalise part of a write to a page |
|
*/ |
|
int afs_write_end(struct file *file, struct address_space *mapping, |
|
loff_t pos, unsigned len, unsigned copied, |
|
struct page *page, void *fsdata) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); |
|
struct key *key = afs_file_key(file); |
|
unsigned long priv; |
|
unsigned int f, from = pos & (PAGE_SIZE - 1); |
|
unsigned int t, to = from + copied; |
|
loff_t i_size, maybe_i_size; |
|
int ret = 0; |
|
|
|
_enter("{%llx:%llu},{%lx}", |
|
vnode->fid.vid, vnode->fid.vnode, page->index); |
|
|
|
if (copied == 0) |
|
goto out; |
|
|
|
maybe_i_size = pos + copied; |
|
|
|
i_size = i_size_read(&vnode->vfs_inode); |
|
if (maybe_i_size > i_size) { |
|
write_seqlock(&vnode->cb_lock); |
|
i_size = i_size_read(&vnode->vfs_inode); |
|
if (maybe_i_size > i_size) |
|
i_size_write(&vnode->vfs_inode, maybe_i_size); |
|
write_sequnlock(&vnode->cb_lock); |
|
} |
|
|
|
if (!PageUptodate(page)) { |
|
if (copied < len) { |
|
/* Try and load any missing data from the server. The |
|
* unmarshalling routine will take care of clearing any |
|
* bits that are beyond the EOF. |
|
*/ |
|
ret = afs_fill_page(vnode, key, pos + copied, |
|
len - copied, page); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
SetPageUptodate(page); |
|
} |
|
|
|
if (PagePrivate(page)) { |
|
priv = page_private(page); |
|
f = afs_page_dirty_from(priv); |
|
t = afs_page_dirty_to(priv); |
|
if (from < f) |
|
f = from; |
|
if (to > t) |
|
t = to; |
|
priv = afs_page_dirty(f, t); |
|
set_page_private(page, priv); |
|
trace_afs_page_dirty(vnode, tracepoint_string("dirty+"), |
|
page->index, priv); |
|
} else { |
|
priv = afs_page_dirty(from, to); |
|
attach_page_private(page, (void *)priv); |
|
trace_afs_page_dirty(vnode, tracepoint_string("dirty"), |
|
page->index, priv); |
|
} |
|
|
|
set_page_dirty(page); |
|
if (PageDirty(page)) |
|
_debug("dirtied"); |
|
ret = copied; |
|
|
|
out: |
|
unlock_page(page); |
|
put_page(page); |
|
return ret; |
|
} |
|
|
|
/* |
|
* kill all the pages in the given range |
|
*/ |
|
static void afs_kill_pages(struct address_space *mapping, |
|
pgoff_t first, pgoff_t last) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
struct pagevec pv; |
|
unsigned count, loop; |
|
|
|
_enter("{%llx:%llu},%lx-%lx", |
|
vnode->fid.vid, vnode->fid.vnode, first, last); |
|
|
|
pagevec_init(&pv); |
|
|
|
do { |
|
_debug("kill %lx-%lx", first, last); |
|
|
|
count = last - first + 1; |
|
if (count > PAGEVEC_SIZE) |
|
count = PAGEVEC_SIZE; |
|
pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); |
|
ASSERTCMP(pv.nr, ==, count); |
|
|
|
for (loop = 0; loop < count; loop++) { |
|
struct page *page = pv.pages[loop]; |
|
ClearPageUptodate(page); |
|
SetPageError(page); |
|
end_page_writeback(page); |
|
if (page->index >= first) |
|
first = page->index + 1; |
|
lock_page(page); |
|
generic_error_remove_page(mapping, page); |
|
unlock_page(page); |
|
} |
|
|
|
__pagevec_release(&pv); |
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} while (first <= last); |
|
|
|
_leave(""); |
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} |
|
|
|
/* |
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* Redirty all the pages in a given range. |
|
*/ |
|
static void afs_redirty_pages(struct writeback_control *wbc, |
|
struct address_space *mapping, |
|
pgoff_t first, pgoff_t last) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
struct pagevec pv; |
|
unsigned count, loop; |
|
|
|
_enter("{%llx:%llu},%lx-%lx", |
|
vnode->fid.vid, vnode->fid.vnode, first, last); |
|
|
|
pagevec_init(&pv); |
|
|
|
do { |
|
_debug("redirty %lx-%lx", first, last); |
|
|
|
count = last - first + 1; |
|
if (count > PAGEVEC_SIZE) |
|
count = PAGEVEC_SIZE; |
|
pv.nr = find_get_pages_contig(mapping, first, count, pv.pages); |
|
ASSERTCMP(pv.nr, ==, count); |
|
|
|
for (loop = 0; loop < count; loop++) { |
|
struct page *page = pv.pages[loop]; |
|
|
|
redirty_page_for_writepage(wbc, page); |
|
end_page_writeback(page); |
|
if (page->index >= first) |
|
first = page->index + 1; |
|
} |
|
|
|
__pagevec_release(&pv); |
|
} while (first <= last); |
|
|
|
_leave(""); |
|
} |
|
|
|
/* |
|
* completion of write to server |
|
*/ |
|
static void afs_pages_written_back(struct afs_vnode *vnode, |
|
pgoff_t first, pgoff_t last) |
|
{ |
|
struct pagevec pv; |
|
unsigned long priv; |
|
unsigned count, loop; |
|
|
|
_enter("{%llx:%llu},{%lx-%lx}", |
|
vnode->fid.vid, vnode->fid.vnode, first, last); |
|
|
|
pagevec_init(&pv); |
|
|
|
do { |
|
_debug("done %lx-%lx", first, last); |
|
|
|
count = last - first + 1; |
|
if (count > PAGEVEC_SIZE) |
|
count = PAGEVEC_SIZE; |
|
pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, |
|
first, count, pv.pages); |
|
ASSERTCMP(pv.nr, ==, count); |
|
|
|
for (loop = 0; loop < count; loop++) { |
|
priv = (unsigned long)detach_page_private(pv.pages[loop]); |
|
trace_afs_page_dirty(vnode, tracepoint_string("clear"), |
|
pv.pages[loop]->index, priv); |
|
end_page_writeback(pv.pages[loop]); |
|
} |
|
first += count; |
|
__pagevec_release(&pv); |
|
} while (first <= last); |
|
|
|
afs_prune_wb_keys(vnode); |
|
_leave(""); |
|
} |
|
|
|
/* |
|
* Find a key to use for the writeback. We cached the keys used to author the |
|
* writes on the vnode. *_wbk will contain the last writeback key used or NULL |
|
* and we need to start from there if it's set. |
|
*/ |
|
static int afs_get_writeback_key(struct afs_vnode *vnode, |
|
struct afs_wb_key **_wbk) |
|
{ |
|
struct afs_wb_key *wbk = NULL; |
|
struct list_head *p; |
|
int ret = -ENOKEY, ret2; |
|
|
|
spin_lock(&vnode->wb_lock); |
|
if (*_wbk) |
|
p = (*_wbk)->vnode_link.next; |
|
else |
|
p = vnode->wb_keys.next; |
|
|
|
while (p != &vnode->wb_keys) { |
|
wbk = list_entry(p, struct afs_wb_key, vnode_link); |
|
_debug("wbk %u", key_serial(wbk->key)); |
|
ret2 = key_validate(wbk->key); |
|
if (ret2 == 0) { |
|
refcount_inc(&wbk->usage); |
|
_debug("USE WB KEY %u", key_serial(wbk->key)); |
|
break; |
|
} |
|
|
|
wbk = NULL; |
|
if (ret == -ENOKEY) |
|
ret = ret2; |
|
p = p->next; |
|
} |
|
|
|
spin_unlock(&vnode->wb_lock); |
|
if (*_wbk) |
|
afs_put_wb_key(*_wbk); |
|
*_wbk = wbk; |
|
return 0; |
|
} |
|
|
|
static void afs_store_data_success(struct afs_operation *op) |
|
{ |
|
struct afs_vnode *vnode = op->file[0].vnode; |
|
|
|
op->ctime = op->file[0].scb.status.mtime_client; |
|
afs_vnode_commit_status(op, &op->file[0]); |
|
if (op->error == 0) { |
|
if (!op->store.laundering) |
|
afs_pages_written_back(vnode, op->store.first, op->store.last); |
|
afs_stat_v(vnode, n_stores); |
|
atomic_long_add((op->store.last * PAGE_SIZE + op->store.last_to) - |
|
(op->store.first * PAGE_SIZE + op->store.first_offset), |
|
&afs_v2net(vnode)->n_store_bytes); |
|
} |
|
} |
|
|
|
static const struct afs_operation_ops afs_store_data_operation = { |
|
.issue_afs_rpc = afs_fs_store_data, |
|
.issue_yfs_rpc = yfs_fs_store_data, |
|
.success = afs_store_data_success, |
|
}; |
|
|
|
/* |
|
* write to a file |
|
*/ |
|
static int afs_store_data(struct address_space *mapping, |
|
pgoff_t first, pgoff_t last, |
|
unsigned offset, unsigned to, bool laundering) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
struct afs_operation *op; |
|
struct afs_wb_key *wbk = NULL; |
|
int ret; |
|
|
|
_enter("%s{%llx:%llu.%u},%lx,%lx,%x,%x", |
|
vnode->volume->name, |
|
vnode->fid.vid, |
|
vnode->fid.vnode, |
|
vnode->fid.unique, |
|
first, last, offset, to); |
|
|
|
ret = afs_get_writeback_key(vnode, &wbk); |
|
if (ret) { |
|
_leave(" = %d [no keys]", ret); |
|
return ret; |
|
} |
|
|
|
op = afs_alloc_operation(wbk->key, vnode->volume); |
|
if (IS_ERR(op)) { |
|
afs_put_wb_key(wbk); |
|
return -ENOMEM; |
|
} |
|
|
|
afs_op_set_vnode(op, 0, vnode); |
|
op->file[0].dv_delta = 1; |
|
op->store.mapping = mapping; |
|
op->file[0].modification = true; |
|
op->store.first = first; |
|
op->store.last = last; |
|
op->store.first_offset = offset; |
|
op->store.last_to = to; |
|
op->store.laundering = laundering; |
|
op->mtime = vnode->vfs_inode.i_mtime; |
|
op->flags |= AFS_OPERATION_UNINTR; |
|
op->ops = &afs_store_data_operation; |
|
|
|
try_next_key: |
|
afs_begin_vnode_operation(op); |
|
afs_wait_for_operation(op); |
|
|
|
switch (op->error) { |
|
case -EACCES: |
|
case -EPERM: |
|
case -ENOKEY: |
|
case -EKEYEXPIRED: |
|
case -EKEYREJECTED: |
|
case -EKEYREVOKED: |
|
_debug("next"); |
|
|
|
ret = afs_get_writeback_key(vnode, &wbk); |
|
if (ret == 0) { |
|
key_put(op->key); |
|
op->key = key_get(wbk->key); |
|
goto try_next_key; |
|
} |
|
break; |
|
} |
|
|
|
afs_put_wb_key(wbk); |
|
_leave(" = %d", op->error); |
|
return afs_put_operation(op); |
|
} |
|
|
|
/* |
|
* Synchronously write back the locked page and any subsequent non-locked dirty |
|
* pages. |
|
*/ |
|
static int afs_write_back_from_locked_page(struct address_space *mapping, |
|
struct writeback_control *wbc, |
|
struct page *primary_page, |
|
pgoff_t final_page) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
struct page *pages[8], *page; |
|
unsigned long count, priv; |
|
unsigned n, offset, to, f, t; |
|
pgoff_t start, first, last; |
|
loff_t i_size, end; |
|
int loop, ret; |
|
|
|
_enter(",%lx", primary_page->index); |
|
|
|
count = 1; |
|
if (test_set_page_writeback(primary_page)) |
|
BUG(); |
|
|
|
/* Find all consecutive lockable dirty pages that have contiguous |
|
* written regions, stopping when we find a page that is not |
|
* immediately lockable, is not dirty or is missing, or we reach the |
|
* end of the range. |
|
*/ |
|
start = primary_page->index; |
|
priv = page_private(primary_page); |
|
offset = afs_page_dirty_from(priv); |
|
to = afs_page_dirty_to(priv); |
|
trace_afs_page_dirty(vnode, tracepoint_string("store"), |
|
primary_page->index, priv); |
|
|
|
WARN_ON(offset == to); |
|
if (offset == to) |
|
trace_afs_page_dirty(vnode, tracepoint_string("WARN"), |
|
primary_page->index, priv); |
|
|
|
if (start >= final_page || |
|
(to < PAGE_SIZE && !test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags))) |
|
goto no_more; |
|
|
|
start++; |
|
do { |
|
_debug("more %lx [%lx]", start, count); |
|
n = final_page - start + 1; |
|
if (n > ARRAY_SIZE(pages)) |
|
n = ARRAY_SIZE(pages); |
|
n = find_get_pages_contig(mapping, start, ARRAY_SIZE(pages), pages); |
|
_debug("fgpc %u", n); |
|
if (n == 0) |
|
goto no_more; |
|
if (pages[0]->index != start) { |
|
do { |
|
put_page(pages[--n]); |
|
} while (n > 0); |
|
goto no_more; |
|
} |
|
|
|
for (loop = 0; loop < n; loop++) { |
|
page = pages[loop]; |
|
if (to != PAGE_SIZE && |
|
!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) |
|
break; |
|
if (page->index > final_page) |
|
break; |
|
if (!trylock_page(page)) |
|
break; |
|
if (!PageDirty(page) || PageWriteback(page)) { |
|
unlock_page(page); |
|
break; |
|
} |
|
|
|
priv = page_private(page); |
|
f = afs_page_dirty_from(priv); |
|
t = afs_page_dirty_to(priv); |
|
if (f != 0 && |
|
!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags)) { |
|
unlock_page(page); |
|
break; |
|
} |
|
to = t; |
|
|
|
trace_afs_page_dirty(vnode, tracepoint_string("store+"), |
|
page->index, priv); |
|
|
|
if (!clear_page_dirty_for_io(page)) |
|
BUG(); |
|
if (test_set_page_writeback(page)) |
|
BUG(); |
|
unlock_page(page); |
|
put_page(page); |
|
} |
|
count += loop; |
|
if (loop < n) { |
|
for (; loop < n; loop++) |
|
put_page(pages[loop]); |
|
goto no_more; |
|
} |
|
|
|
start += loop; |
|
} while (start <= final_page && count < 65536); |
|
|
|
no_more: |
|
/* We now have a contiguous set of dirty pages, each with writeback |
|
* set; the first page is still locked at this point, but all the rest |
|
* have been unlocked. |
|
*/ |
|
unlock_page(primary_page); |
|
|
|
first = primary_page->index; |
|
last = first + count - 1; |
|
|
|
end = (loff_t)last * PAGE_SIZE + to; |
|
i_size = i_size_read(&vnode->vfs_inode); |
|
|
|
_debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); |
|
if (end > i_size) |
|
to = i_size & ~PAGE_MASK; |
|
|
|
ret = afs_store_data(mapping, first, last, offset, to, false); |
|
switch (ret) { |
|
case 0: |
|
ret = count; |
|
break; |
|
|
|
default: |
|
pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret); |
|
fallthrough; |
|
case -EACCES: |
|
case -EPERM: |
|
case -ENOKEY: |
|
case -EKEYEXPIRED: |
|
case -EKEYREJECTED: |
|
case -EKEYREVOKED: |
|
afs_redirty_pages(wbc, mapping, first, last); |
|
mapping_set_error(mapping, ret); |
|
break; |
|
|
|
case -EDQUOT: |
|
case -ENOSPC: |
|
afs_redirty_pages(wbc, mapping, first, last); |
|
mapping_set_error(mapping, -ENOSPC); |
|
break; |
|
|
|
case -EROFS: |
|
case -EIO: |
|
case -EREMOTEIO: |
|
case -EFBIG: |
|
case -ENOENT: |
|
case -ENOMEDIUM: |
|
case -ENXIO: |
|
trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail); |
|
afs_kill_pages(mapping, first, last); |
|
mapping_set_error(mapping, ret); |
|
break; |
|
} |
|
|
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* write a page back to the server |
|
* - the caller locked the page for us |
|
*/ |
|
int afs_writepage(struct page *page, struct writeback_control *wbc) |
|
{ |
|
int ret; |
|
|
|
_enter("{%lx},", page->index); |
|
|
|
ret = afs_write_back_from_locked_page(page->mapping, wbc, page, |
|
wbc->range_end >> PAGE_SHIFT); |
|
if (ret < 0) { |
|
_leave(" = %d", ret); |
|
return 0; |
|
} |
|
|
|
wbc->nr_to_write -= ret; |
|
|
|
_leave(" = 0"); |
|
return 0; |
|
} |
|
|
|
/* |
|
* write a region of pages back to the server |
|
*/ |
|
static int afs_writepages_region(struct address_space *mapping, |
|
struct writeback_control *wbc, |
|
pgoff_t index, pgoff_t end, pgoff_t *_next) |
|
{ |
|
struct page *page; |
|
int ret, n; |
|
|
|
_enter(",,%lx,%lx,", index, end); |
|
|
|
do { |
|
n = find_get_pages_range_tag(mapping, &index, end, |
|
PAGECACHE_TAG_DIRTY, 1, &page); |
|
if (!n) |
|
break; |
|
|
|
_debug("wback %lx", page->index); |
|
|
|
/* |
|
* at this point we hold neither the i_pages lock nor the |
|
* page lock: the page may be truncated or invalidated |
|
* (changing page->mapping to NULL), or even swizzled |
|
* back from swapper_space to tmpfs file mapping |
|
*/ |
|
ret = lock_page_killable(page); |
|
if (ret < 0) { |
|
put_page(page); |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
if (page->mapping != mapping || !PageDirty(page)) { |
|
unlock_page(page); |
|
put_page(page); |
|
continue; |
|
} |
|
|
|
if (PageWriteback(page)) { |
|
unlock_page(page); |
|
if (wbc->sync_mode != WB_SYNC_NONE) |
|
wait_on_page_writeback(page); |
|
put_page(page); |
|
continue; |
|
} |
|
|
|
if (!clear_page_dirty_for_io(page)) |
|
BUG(); |
|
ret = afs_write_back_from_locked_page(mapping, wbc, page, end); |
|
put_page(page); |
|
if (ret < 0) { |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
wbc->nr_to_write -= ret; |
|
|
|
cond_resched(); |
|
} while (index < end && wbc->nr_to_write > 0); |
|
|
|
*_next = index; |
|
_leave(" = 0 [%lx]", *_next); |
|
return 0; |
|
} |
|
|
|
/* |
|
* write some of the pending data back to the server |
|
*/ |
|
int afs_writepages(struct address_space *mapping, |
|
struct writeback_control *wbc) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
pgoff_t start, end, next; |
|
int ret; |
|
|
|
_enter(""); |
|
|
|
/* We have to be careful as we can end up racing with setattr() |
|
* truncating the pagecache since the caller doesn't take a lock here |
|
* to prevent it. |
|
*/ |
|
if (wbc->sync_mode == WB_SYNC_ALL) |
|
down_read(&vnode->validate_lock); |
|
else if (!down_read_trylock(&vnode->validate_lock)) |
|
return 0; |
|
|
|
if (wbc->range_cyclic) { |
|
start = mapping->writeback_index; |
|
end = -1; |
|
ret = afs_writepages_region(mapping, wbc, start, end, &next); |
|
if (start > 0 && wbc->nr_to_write > 0 && ret == 0) |
|
ret = afs_writepages_region(mapping, wbc, 0, start, |
|
&next); |
|
mapping->writeback_index = next; |
|
} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { |
|
end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT); |
|
ret = afs_writepages_region(mapping, wbc, 0, end, &next); |
|
if (wbc->nr_to_write > 0) |
|
mapping->writeback_index = next; |
|
} else { |
|
start = wbc->range_start >> PAGE_SHIFT; |
|
end = wbc->range_end >> PAGE_SHIFT; |
|
ret = afs_writepages_region(mapping, wbc, start, end, &next); |
|
} |
|
|
|
up_read(&vnode->validate_lock); |
|
_leave(" = %d", ret); |
|
return ret; |
|
} |
|
|
|
/* |
|
* write to an AFS file |
|
*/ |
|
ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp)); |
|
ssize_t result; |
|
size_t count = iov_iter_count(from); |
|
|
|
_enter("{%llx:%llu},{%zu},", |
|
vnode->fid.vid, vnode->fid.vnode, count); |
|
|
|
if (IS_SWAPFILE(&vnode->vfs_inode)) { |
|
printk(KERN_INFO |
|
"AFS: Attempt to write to active swap file!\n"); |
|
return -EBUSY; |
|
} |
|
|
|
if (!count) |
|
return 0; |
|
|
|
result = generic_file_write_iter(iocb, from); |
|
|
|
_leave(" = %zd", result); |
|
return result; |
|
} |
|
|
|
/* |
|
* flush any dirty pages for this process, and check for write errors. |
|
* - the return status from this call provides a reliable indication of |
|
* whether any write errors occurred for this process. |
|
*/ |
|
int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
|
{ |
|
struct inode *inode = file_inode(file); |
|
struct afs_vnode *vnode = AFS_FS_I(inode); |
|
|
|
_enter("{%llx:%llu},{n=%pD},%d", |
|
vnode->fid.vid, vnode->fid.vnode, file, |
|
datasync); |
|
|
|
return file_write_and_wait_range(file, start, end); |
|
} |
|
|
|
/* |
|
* notification that a previously read-only page is about to become writable |
|
* - if it returns an error, the caller will deliver a bus error signal |
|
*/ |
|
vm_fault_t afs_page_mkwrite(struct vm_fault *vmf) |
|
{ |
|
struct file *file = vmf->vma->vm_file; |
|
struct inode *inode = file_inode(file); |
|
struct afs_vnode *vnode = AFS_FS_I(inode); |
|
unsigned long priv; |
|
|
|
_enter("{{%llx:%llu}},{%lx}", |
|
vnode->fid.vid, vnode->fid.vnode, vmf->page->index); |
|
|
|
sb_start_pagefault(inode->i_sb); |
|
|
|
/* Wait for the page to be written to the cache before we allow it to |
|
* be modified. We then assume the entire page will need writing back. |
|
*/ |
|
#ifdef CONFIG_AFS_FSCACHE |
|
fscache_wait_on_page_write(vnode->cache, vmf->page); |
|
#endif |
|
|
|
if (wait_on_page_writeback_killable(vmf->page)) |
|
return VM_FAULT_RETRY; |
|
|
|
if (lock_page_killable(vmf->page) < 0) |
|
return VM_FAULT_RETRY; |
|
|
|
/* We mustn't change page->private until writeback is complete as that |
|
* details the portion of the page we need to write back and we might |
|
* need to redirty the page if there's a problem. |
|
*/ |
|
wait_on_page_writeback(vmf->page); |
|
|
|
priv = afs_page_dirty(0, PAGE_SIZE); |
|
priv = afs_page_dirty_mmapped(priv); |
|
trace_afs_page_dirty(vnode, tracepoint_string("mkwrite"), |
|
vmf->page->index, priv); |
|
if (PagePrivate(vmf->page)) |
|
set_page_private(vmf->page, priv); |
|
else |
|
attach_page_private(vmf->page, (void *)priv); |
|
file_update_time(file); |
|
|
|
sb_end_pagefault(inode->i_sb); |
|
return VM_FAULT_LOCKED; |
|
} |
|
|
|
/* |
|
* Prune the keys cached for writeback. The caller must hold vnode->wb_lock. |
|
*/ |
|
void afs_prune_wb_keys(struct afs_vnode *vnode) |
|
{ |
|
LIST_HEAD(graveyard); |
|
struct afs_wb_key *wbk, *tmp; |
|
|
|
/* Discard unused keys */ |
|
spin_lock(&vnode->wb_lock); |
|
|
|
if (!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_WRITEBACK) && |
|
!mapping_tagged(&vnode->vfs_inode.i_data, PAGECACHE_TAG_DIRTY)) { |
|
list_for_each_entry_safe(wbk, tmp, &vnode->wb_keys, vnode_link) { |
|
if (refcount_read(&wbk->usage) == 1) |
|
list_move(&wbk->vnode_link, &graveyard); |
|
} |
|
} |
|
|
|
spin_unlock(&vnode->wb_lock); |
|
|
|
while (!list_empty(&graveyard)) { |
|
wbk = list_entry(graveyard.next, struct afs_wb_key, vnode_link); |
|
list_del(&wbk->vnode_link); |
|
afs_put_wb_key(wbk); |
|
} |
|
} |
|
|
|
/* |
|
* Clean up a page during invalidation. |
|
*/ |
|
int afs_launder_page(struct page *page) |
|
{ |
|
struct address_space *mapping = page->mapping; |
|
struct afs_vnode *vnode = AFS_FS_I(mapping->host); |
|
unsigned long priv; |
|
unsigned int f, t; |
|
int ret = 0; |
|
|
|
_enter("{%lx}", page->index); |
|
|
|
priv = page_private(page); |
|
if (clear_page_dirty_for_io(page)) { |
|
f = 0; |
|
t = PAGE_SIZE; |
|
if (PagePrivate(page)) { |
|
f = afs_page_dirty_from(priv); |
|
t = afs_page_dirty_to(priv); |
|
} |
|
|
|
trace_afs_page_dirty(vnode, tracepoint_string("launder"), |
|
page->index, priv); |
|
ret = afs_store_data(mapping, page->index, page->index, t, f, true); |
|
} |
|
|
|
priv = (unsigned long)detach_page_private(page); |
|
trace_afs_page_dirty(vnode, tracepoint_string("laundered"), |
|
page->index, priv); |
|
|
|
#ifdef CONFIG_AFS_FSCACHE |
|
if (PageFsCache(page)) { |
|
fscache_wait_on_page_write(vnode->cache, page); |
|
fscache_uncache_page(vnode->cache, page); |
|
} |
|
#endif |
|
return ret; |
|
}
|
|
|