kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

ext4: Always use ext4_bio_write_page() for writeout

Browse source 
Currently we sometimes used block_write_full_page() and sometimes
ext4_bio_write_page() for writeback (depending on mount options and call
path). Let's always use ext4_bio_write_page() to simplify things a bit.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Jan Kara 2013-01-28 09:30:52 -05:00 committed by Theodore Ts'o
parent 8bad6fc813
commit 36ade451a5
4 changed files with 16 additions and 124 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
fs/ext4/ext4.h
View file

@ -215,7 +215,6 @@ typedef struct ext4_io_end {
struct list_head list; /* per-file finished IO list */
struct inode *inode; /* file being written to */
unsigned int flag; /* unwritten or not */
struct page *page; /* for writepage() path */
loff_t offset; /* offset in the file */
ssize_t size; /* size of the extent */
struct work_struct work; /* data work queue */
@ -985,7 +984,6 @@ struct ext4_inode_info {
#define EXT4_MOUNT_DIOREAD_NOLOCK 0x400000 /* Enable support for dio read nolocking */
#define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */
#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
#define EXT4_MOUNT_MBLK_IO_SUBMIT 0x4000000 /* multi-block io submits */
#define EXT4_MOUNT_DELALLOC 0x8000000 /* Delalloc support */
#define EXT4_MOUNT_DATA_ERR_ABORT 0x10000000 /* Abort on file data write */
#define EXT4_MOUNT_BLOCK_VALIDITY 0x20000000 /* Block validity checking */

129
fs/ext4/inode.c
View file

@ -134,8 +134,6 @@ static inline int ext4_begin_ordered_truncate(struct inode *inode,
static void ext4_invalidatepage(struct page *page, unsigned long offset);
static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create);
static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
static int __ext4_journalled_writepage(struct page *page, unsigned int len);
static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
@ -808,11 +806,10 @@ int ext4_walk_page_buffers(handle_t *handle,
* and the commit_write(). So doing the jbd2_journal_start at the start of
* prepare_write() is the right place.
*
* Also, this function can nest inside ext4_writepage() ->
* block_write_full_page(). In that case, we *know* that ext4_writepage()
* has generated enough buffer credits to do the whole page. So we won't
* block on the journal in that case, which is good, because the caller may
* be PF_MEMALLOC.
* Also, this function can nest inside ext4_writepage(). In that case, we
* *know* that ext4_writepage() has generated enough buffer credits to do the
* whole page. So we won't block on the journal in that case, which is good,
* because the caller may be PF_MEMALLOC.
*
* By accident, ext4 can be reentered when a transaction is open via
* quota file writes. If we were to commit the transaction while thus
@ -1463,18 +1460,9 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd,
*/
if (unlikely(journal_data && PageChecked(page)))
err = __ext4_journalled_writepage(page, len);
else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT))
else
err = ext4_bio_write_page(&io_submit, page,
len, mpd->wbc);
else if (buffer_uninit(page_bufs)) {
ext4_set_bh_endio(page_bufs, inode);
err = block_write_full_page_endio(page,
noalloc_get_block_write,
mpd->wbc, ext4_end_io_buffer_write);
} else
err = block_write_full_page(page,
noalloc_get_block_write, mpd->wbc);
if (!err)
mpd->pages_written++;
/*
@ -1891,16 +1879,16 @@ int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
}
/*
* This function is used as a standard get_block_t calback function
* when there is no desire to allocate any blocks. It is used as a
* callback function for block_write_begin() and block_write_full_page().
* These functions should only try to map a single block at a time.
* This function is used as a standard get_block_t calback function when there
* is no desire to allocate any blocks. It is used as a callback function for
* block_write_begin(). These functions should only try to map a single block
* at a time.
*
* Since this function doesn't do block allocations even if the caller
* requests it by passing in create=1, it is critically important that
* any caller checks to make sure that any buffer heads are returned
* by this function are either all already mapped or marked for
* delayed allocation before calling block_write_full_page(). Otherwise,
* delayed allocation before calling ext4_bio_write_page(). Otherwise,
* b_blocknr could be left unitialized, and the page write functions will
* be taken by surprise.
*/
@ -2040,6 +2028,7 @@ static int ext4_writepage(struct page *page,
unsigned int len;
struct buffer_head *page_bufs = NULL;
struct inode *inode = page->mapping->host;
struct ext4_io_submit io_submit;
trace_ext4_writepage(page);
size = i_size_read(inode);
@ -2089,14 +2078,9 @@ static int ext4_writepage(struct page *page,
*/
return __ext4_journalled_writepage(page, len);
if (buffer_uninit(page_bufs)) {
ext4_set_bh_endio(page_bufs, inode);
ret = block_write_full_page_endio(page, noalloc_get_block_write,
wbc, ext4_end_io_buffer_write);
} else
ret = block_write_full_page(page, noalloc_get_block_write,
wbc);
memset(&io_submit, 0, sizeof(io_submit));
ret = ext4_bio_write_page(&io_submit, page, len, wbc);
ext4_io_submit(&io_submit);
return ret;
}
@ -2858,36 +2842,10 @@ ext4_readpages(struct file *file, struct address_space *mapping,
return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
}
static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset)
{
struct buffer_head *head, *bh;
unsigned int curr_off = 0;
if (!page_has_buffers(page))
return;
head = bh = page_buffers(page);
do {
if (offset <= curr_off && test_clear_buffer_uninit(bh)
&& bh->b_private) {
ext4_free_io_end(bh->b_private);
bh->b_private = NULL;
bh->b_end_io = NULL;
}
curr_off = curr_off + bh->b_size;
bh = bh->b_this_page;
} while (bh != head);
}
static void ext4_invalidatepage(struct page *page, unsigned long offset)
{
trace_ext4_invalidatepage(page, offset);
/*
* free any io_end structure allocated for buffers to be discarded
*/
if (ext4_should_dioread_nolock(page->mapping->host))
ext4_invalidatepage_free_endio(page, offset);
/* No journalling happens on data buffers when this function is used */
WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page)));
@ -2993,65 +2951,6 @@ out:
ext4_add_complete_io(io_end);
}
static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
{
ext4_io_end_t *io_end = bh->b_private;
struct inode *inode;
if (!test_clear_buffer_uninit(bh) || !io_end)
goto out;
if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
ext4_msg(io_end->inode->i_sb, KERN_INFO,
"sb umounted, discard end_io request for inode %lu",
io_end->inode->i_ino);
ext4_free_io_end(io_end);
goto out;
}
/*
* It may be over-defensive here to check EXT4_IO_END_UNWRITTEN now,
* but being more careful is always safe for the future change.
*/
inode = io_end->inode;
ext4_set_io_unwritten_flag(inode, io_end);
ext4_add_complete_io(io_end);
out:
bh->b_private = NULL;
bh->b_end_io = NULL;
clear_buffer_uninit(bh);
end_buffer_async_write(bh, uptodate);
}
static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
{
ext4_io_end_t *io_end;
struct page *page = bh->b_page;
loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
size_t size = bh->b_size;
retry:
io_end = ext4_init_io_end(inode, GFP_ATOMIC);
if (!io_end) {
pr_warn_ratelimited("%s: allocation fail\n", __func__);
schedule();
goto retry;
}
io_end->offset = offset;
io_end->size = size;
/*
* We need to hold a reference to the page to make sure it
* doesn't get evicted before ext4_end_io_work() has a chance
* to convert the extent from written to unwritten.
*/
io_end->page = page;
get_page(io_end->page);
bh->b_private = io_end;
bh->b_end_io = ext4_end_io_buffer_write;
return 0;
}
/*
* For ext4 extent files, ext4 will do direct-io write to holes,
* preallocated extents, and those write extend the file, no need to

2
fs/ext4/page-io.c
View file

@ -73,8 +73,6 @@ void ext4_free_io_end(ext4_io_end_t *io)
BUG_ON(!list_empty(&io->list));
BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN);
if (io->page)
put_page(io->page);
for (i = 0; i < io->num_io_pages; i++)
put_io_page(io->pages[i]);
io->num_io_pages = 0;

7
fs/ext4/super.c
View file

@ -1280,8 +1280,8 @@ static const match_table_t tokens = {
{Opt_stripe, "stripe=%u"},
{Opt_delalloc, "delalloc"},
{Opt_nodelalloc, "nodelalloc"},
{Opt_mblk_io_submit, "mblk_io_submit"},
{Opt_nomblk_io_submit, "nomblk_io_submit"},
{Opt_removed, "mblk_io_submit"},
{Opt_removed, "nomblk_io_submit"},
{Opt_block_validity, "block_validity"},
{Opt_noblock_validity, "noblock_validity"},
{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
@ -1415,8 +1415,6 @@ static const struct mount_opts {
{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
@ -3381,7 +3379,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
#ifdef CONFIG_EXT4_FS_POSIX_ACL
set_opt(sb, POSIX_ACL);
#endif
set_opt(sb, MBLK_IO_SUBMIT);
if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
set_opt(sb, JOURNAL_DATA);
else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)