From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/ext4/page-io.c | 204 +++++++++++++++++++++++++++++---------------------
1 files changed, 117 insertions(+), 87 deletions(-)
diff --git a/kernel/fs/ext4/page-io.c b/kernel/fs/ext4/page-io.c
index e2fad25..a94cc7b 100644
--- a/kernel/fs/ext4/page-io.c
+++ b/kernel/fs/ext4/page-io.c
@@ -31,18 +31,56 @@
#include "acl.h"
static struct kmem_cache *io_end_cachep;
+static struct kmem_cache *io_end_vec_cachep;
int __init ext4_init_pageio(void)
{
io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT);
if (io_end_cachep == NULL)
return -ENOMEM;
+
+ io_end_vec_cachep = KMEM_CACHE(ext4_io_end_vec, 0);
+ if (io_end_vec_cachep == NULL) {
+ kmem_cache_destroy(io_end_cachep);
+ return -ENOMEM;
+ }
return 0;
}
void ext4_exit_pageio(void)
{
kmem_cache_destroy(io_end_cachep);
+ kmem_cache_destroy(io_end_vec_cachep);
+}
+
+struct ext4_io_end_vec *ext4_alloc_io_end_vec(ext4_io_end_t *io_end)
+{
+ struct ext4_io_end_vec *io_end_vec;
+
+ io_end_vec = kmem_cache_zalloc(io_end_vec_cachep, GFP_NOFS);
+ if (!io_end_vec)
+ return ERR_PTR(-ENOMEM);
+ INIT_LIST_HEAD(&io_end_vec->list);
+ list_add_tail(&io_end_vec->list, &io_end->list_vec);
+ return io_end_vec;
+}
+
+static void ext4_free_io_end_vec(ext4_io_end_t *io_end)
+{
+ struct ext4_io_end_vec *io_end_vec, *tmp;
+
+ if (list_empty(&io_end->list_vec))
+ return;
+ list_for_each_entry_safe(io_end_vec, tmp, &io_end->list_vec, list) {
+ list_del(&io_end_vec->list);
+ kmem_cache_free(io_end_vec_cachep, io_end_vec);
+ }
+}
+
+struct ext4_io_end_vec *ext4_last_io_end_vec(ext4_io_end_t *io_end)
+{
+ BUG_ON(list_empty(&io_end->list_vec));
+ return list_last_entry(&io_end->list_vec, struct ext4_io_end_vec, list);
}
/*
@@ -61,10 +99,10 @@
static void ext4_finish_bio(struct bio *bio)
{
- int i;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, iter_all) {
struct page *page = bvec->bv_page;
struct page *bounce_page = NULL;
struct buffer_head *bh, *head;
@@ -87,11 +125,10 @@
}
bh = head = page_buffers(page);
/*
- * We check all buffers in the page under BH_Uptodate_Lock
+ * We check all buffers in the page under b_uptodate_lock
* to avoid races with other end io clearing async_write flags
*/
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
+ spin_lock_irqsave(&head->b_uptodate_lock, flags);
do {
if (bh_offset(bh) < bio_start ||
bh_offset(bh) + bh->b_size > bio_end) {
@@ -100,11 +137,12 @@
continue;
}
clear_buffer_async_write(bh);
- if (bio->bi_status)
+ if (bio->bi_status) {
+ set_buffer_write_io_error(bh);
buffer_io_error(bh);
+ }
} while ((bh = bh->b_this_page) != head);
- bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&head->b_uptodate_lock, flags);
if (!under_io) {
fscrypt_free_bounce_page(bounce_page);
end_page_writeback(page);
@@ -125,6 +163,7 @@
ext4_finish_bio(bio);
bio_put(bio);
}
+ ext4_free_io_end_vec(io_end);
kmem_cache_free(io_end_cachep, io_end);
}
@@ -136,29 +175,26 @@
* cannot get to ext4_ext_truncate() before all IOs overlapping that range are
* completed (happens from ext4_free_ioend()).
*/
-static int ext4_end_io(ext4_io_end_t *io)
+static int ext4_end_io_end(ext4_io_end_t *io_end)
{
- struct inode *inode = io->inode;
- loff_t offset = io->offset;
- ssize_t size = io->size;
- handle_t *handle = io->handle;
+ struct inode *inode = io_end->inode;
+ handle_t *handle = io_end->handle;
int ret = 0;
- ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
+ ext4_debug("ext4_end_io_nolock: io_end 0x%p from inode %lu,list->next 0x%p,"
"list->prev 0x%p\n",
- io, inode->i_ino, io->list.next, io->list.prev);
+ io_end, inode->i_ino, io_end->list.next, io_end->list.prev);
- io->handle = NULL; /* Following call will use up the handle */
- ret = ext4_convert_unwritten_extents(handle, inode, offset, size);
+ io_end->handle = NULL; /* Following call will use up the handle */
+ ret = ext4_convert_unwritten_io_end_vec(handle, io_end);
if (ret < 0 && !ext4_forced_shutdown(EXT4_SB(inode->i_sb))) {
ext4_msg(inode->i_sb, KERN_EMERG,
"failed to convert unwritten extents to written "
"extents -- potential data loss! "
- "(inode %lu, offset %llu, size %zd, error %d)",
- inode->i_ino, offset, size, ret);
+ "(inode %lu, error %d)", inode->i_ino, ret);
}
- ext4_clear_io_unwritten_flag(io);
- ext4_release_io_end(io);
+ ext4_clear_io_unwritten_flag(io_end);
+ ext4_release_io_end(io_end);
return ret;
}
@@ -166,21 +202,21 @@
{
#ifdef EXT4FS_DEBUG
struct list_head *cur, *before, *after;
- ext4_io_end_t *io, *io0, *io1;
+ ext4_io_end_t *io_end, *io_end0, *io_end1;
if (list_empty(head))
return;
ext4_debug("Dump inode %lu completed io list\n", inode->i_ino);
- list_for_each_entry(io, head, list) {
- cur = &io->list;
+ list_for_each_entry(io_end, head, list) {
+ cur = &io_end->list;
before = cur->prev;
- io0 = container_of(before, ext4_io_end_t, list);
+ io_end0 = container_of(before, ext4_io_end_t, list);
after = cur->next;
- io1 = container_of(after, ext4_io_end_t, list);
+ io_end1 = container_of(after, ext4_io_end_t, list);
ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
- io, inode->i_ino, io0, io1);
+ io_end, inode->i_ino, io_end0, io_end1);
}
#endif
}
@@ -207,7 +243,7 @@
static int ext4_do_flush_completed_IO(struct inode *inode,
struct list_head *head)
{
- ext4_io_end_t *io;
+ ext4_io_end_t *io_end;
struct list_head unwritten;
unsigned long flags;
struct ext4_inode_info *ei = EXT4_I(inode);
@@ -219,11 +255,11 @@
spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
while (!list_empty(&unwritten)) {
- io = list_entry(unwritten.next, ext4_io_end_t, list);
- BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN));
- list_del_init(&io->list);
+ io_end = list_entry(unwritten.next, ext4_io_end_t, list);
+ BUG_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN));
+ list_del_init(&io_end->list);
- err = ext4_end_io(io);
+ err = ext4_end_io_end(io_end);
if (unlikely(!ret && err))
ret = err;
}
@@ -242,19 +278,22 @@
ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
{
- ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags);
- if (io) {
- io->inode = inode;
- INIT_LIST_HEAD(&io->list);
- atomic_set(&io->count, 1);
+ ext4_io_end_t *io_end = kmem_cache_zalloc(io_end_cachep, flags);
+
+ if (io_end) {
+ io_end->inode = inode;
+ INIT_LIST_HEAD(&io_end->list);
+ INIT_LIST_HEAD(&io_end->list_vec);
+ atomic_set(&io_end->count, 1);
}
- return io;
+ return io_end;
}
void ext4_put_io_end_defer(ext4_io_end_t *io_end)
{
if (atomic_dec_and_test(&io_end->count)) {
- if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) {
+ if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) ||
+ list_empty(&io_end->list_vec)) {
ext4_release_io_end(io_end);
return;
}
@@ -268,9 +307,8 @@
if (atomic_dec_and_test(&io_end->count)) {
if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
- err = ext4_convert_unwritten_extents(io_end->handle,
- io_end->inode, io_end->offset,
- io_end->size);
+ err = ext4_convert_unwritten_io_end_vec(io_end->handle,
+ io_end);
io_end->handle = NULL;
ext4_clear_io_unwritten_flag(io_end);
}
@@ -307,10 +345,8 @@
struct inode *inode = io_end->inode;
ext4_warning(inode->i_sb, "I/O error %d writing to inode %lu "
- "(offset %llu size %ld starting block %llu)",
+ "starting block %llu)",
bio->bi_status, inode->i_ino,
- (unsigned long long) io_end->offset,
- (long) io_end->size,
(unsigned long long)
bi_sector >> (inode->i_blkbits - 9));
mapping_set_error(inode->i_mapping,
@@ -358,29 +394,31 @@
io->io_end = NULL;
}
-static int io_submit_init_bio(struct ext4_io_submit *io,
- struct buffer_head *bh)
+static void io_submit_init_bio(struct ext4_io_submit *io,
+ struct buffer_head *bh)
{
struct bio *bio;
+ /*
+ * bio_alloc will _always_ be able to allocate a bio if
+ * __GFP_DIRECT_RECLAIM is set, see comments for bio_alloc_bioset().
+ */
bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);
- if (!bio)
- return -ENOMEM;
fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO);
- wbc_init_bio(io->io_wbc, bio);
bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
bio_set_dev(bio, bh->b_bdev);
bio->bi_end_io = ext4_end_bio;
bio->bi_private = ext4_get_io_end(io->io_end);
io->io_bio = bio;
io->io_next_block = bh->b_blocknr;
- return 0;
+ wbc_init_bio(io->io_wbc, bio);
}
-static int io_submit_add_bh(struct ext4_io_submit *io,
- struct inode *inode,
- struct page *page,
- struct buffer_head *bh)
+static void io_submit_add_bh(struct ext4_io_submit *io,
+ struct inode *inode,
+ struct page *pagecache_page,
+ struct page *bounce_page,
+ struct buffer_head *bh)
{
int ret;
@@ -390,17 +428,15 @@
ext4_io_submit(io);
}
if (io->io_bio == NULL) {
- ret = io_submit_init_bio(io, bh);
- if (ret)
- return ret;
+ io_submit_init_bio(io, bh);
io->io_bio->bi_write_hint = inode->i_write_hint;
}
- ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh));
+ ret = bio_add_page(io->io_bio, bounce_page ?: pagecache_page,
+ bh->b_size, bh_offset(bh));
if (ret != bh->b_size)
goto submit_and_retry;
- wbc_account_io(io->io_wbc, page, bh->b_size);
+ wbc_account_cgroup_owner(io->io_wbc, pagecache_page, bh->b_size);
io->io_next_block++;
- return 0;
}
int ext4_bio_write_page(struct ext4_io_submit *io,
@@ -461,18 +497,24 @@
ext4_io_submit(io);
continue;
}
- if (buffer_new(bh)) {
+ if (buffer_new(bh))
clear_buffer_new(bh);
- clean_bdev_bh_alias(bh);
- }
set_buffer_async_write(bh);
nr_to_submit++;
} while ((bh = bh->b_this_page) != head);
bh = head = page_buffers(page);
+ /*
+ * If any blocks are being written to an encrypted file, encrypt them
+ * into a bounce page. For simplicity, just encrypt until the last
+ * block which might be needed. This may cause some unneeded blocks
+ * (e.g. holes) to be unnecessarily encrypted, but this is rare and
+ * can't happen in the common case of blocksize == PAGE_SIZE.
+ */
if (fscrypt_inode_uses_fs_layer_crypto(inode) && nr_to_submit) {
gfp_t gfp_flags = GFP_NOFS;
+ unsigned int enc_bytes = round_up(len, i_blocksize(inode));
/*
* Since bounce page allocation uses a mempool, we can only use
@@ -482,7 +524,7 @@
if (io->io_bio)
gfp_flags = GFP_NOWAIT | __GFP_NOWARN;
retry_encrypt:
- bounce_page = fscrypt_encrypt_pagecache_blocks(page, PAGE_SIZE,
+ bounce_page = fscrypt_encrypt_pagecache_blocks(page, enc_bytes,
0, gfp_flags);
if (IS_ERR(bounce_page)) {
ret = PTR_ERR(bounce_page);
@@ -496,8 +538,14 @@
congestion_wait(BLK_RW_ASYNC, HZ/50);
goto retry_encrypt;
}
- bounce_page = NULL;
- goto out;
+
+ printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret);
+ redirty_page_for_writepage(wbc, page);
+ do {
+ clear_buffer_async_write(bh);
+ bh = bh->b_this_page;
+ } while (bh != head);
+ goto unlock;
}
}
@@ -505,30 +553,12 @@
do {
if (!buffer_async_write(bh))
continue;
- ret = io_submit_add_bh(io, inode, bounce_page ?: page, bh);
- if (ret) {
- /*
- * We only get here on ENOMEM. Not much else
- * we can do but mark the page as dirty, and
- * better luck next time.
- */
- break;
- }
+ io_submit_add_bh(io, inode, page, bounce_page, bh);
nr_submitted++;
clear_buffer_dirty(bh);
} while ((bh = bh->b_this_page) != head);
- /* Error stopped previous loop? Clean up buffers... */
- if (ret) {
- out:
- fscrypt_free_bounce_page(bounce_page);
- printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret);
- redirty_page_for_writepage(wbc, page);
- do {
- clear_buffer_async_write(bh);
- bh = bh->b_this_page;
- } while (bh != head);
- }
+unlock:
unlock_page(page);
/* Nothing submitted - we have to end page writeback */
if (!nr_submitted)
--
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