xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

gfs2: iomap direct I/O support

Browse Source 
The page unmapping previously done in gfs2_direct_IO is now done
generically in iomap_dio_rw.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
This commit is contained in:
Andreas Gruenbacher
2018-06-19 15:08:02 +01:00
parent bcfe94139a
commit 967bcc91b0
3 changed files with 136 additions and 110 deletions
Download Patch File Download Diff File Expand all files Collapse all files

100
fs/gfs2/aops.c
View File

@@ -84,12 +84,6 @@ static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
return 0;
}
static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
struct buffer_head *bh_result, int create)
{
return gfs2_block_map(inode, lblock, bh_result, 0);
}
/**
* gfs2_writepage_common - Common bits of writepage
* @page: The page to be written
@@ -1024,96 +1018,6 @@ out:
try_to_release_page(page, 0);
}
/**
* gfs2_ok_for_dio - check that dio is valid on this file
* @ip: The inode
* @offset: The offset at which we are reading or writing
*
* Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
* 1 (to accept the i/o request)
*/
static int gfs2_ok_for_dio(struct gfs2_inode *ip, loff_t offset)
{
/*
* Should we return an error here? I can't see that O_DIRECT for
* a stuffed file makes any sense. For now we'll silently fall
* back to buffered I/O
*/
if (gfs2_is_stuffed(ip))
return 0;
if (offset >= i_size_read(&ip->i_inode))
return 0;
return 1;
}
static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct address_space *mapping = inode->i_mapping;
struct gfs2_inode *ip = GFS2_I(inode);
loff_t offset = iocb->ki_pos;
struct gfs2_holder gh;
int rv;
/*
* Deferred lock, even if its a write, since we do no allocation
* on this path. All we need change is atime, and this lock mode
* ensures that other nodes have flushed their buffered read caches
* (i.e. their page cache entries for this inode). We do not,
* unfortunately have the option of only flushing a range like
* the VFS does.
*/
gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
rv = gfs2_glock_nq(&gh);
if (rv)
goto out_uninit;
rv = gfs2_ok_for_dio(ip, offset);
if (rv != 1)
goto out; /* dio not valid, fall back to buffered i/o */
/*
* Now since we are holding a deferred (CW) lock at this point, you
* might be wondering why this is ever needed. There is a case however
* where we've granted a deferred local lock against a cached exclusive
* glock. That is ok provided all granted local locks are deferred, but
* it also means that it is possible to encounter pages which are
* cached and possibly also mapped. So here we check for that and sort
* them out ahead of the dio. The glock state machine will take care of
* everything else.
*
* If in fact the cached glock state (gl->gl_state) is deferred (CW) in
* the first place, mapping->nr_pages will always be zero.
*/
if (mapping->nrpages) {
loff_t lstart = offset & ~(PAGE_SIZE - 1);
loff_t len = iov_iter_count(iter);
loff_t end = PAGE_ALIGN(offset + len) - 1;
rv = 0;
if (len == 0)
goto out;
if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len);
rv = filemap_write_and_wait_range(mapping, lstart, end);
if (rv)
goto out;
if (iov_iter_rw(iter) == WRITE)
truncate_inode_pages_range(mapping, lstart, end);
}
rv = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
gfs2_get_block_direct, NULL, NULL, 0);
out:
gfs2_glock_dq(&gh);
out_uninit:
gfs2_holder_uninit(&gh);
return rv;
}
/**
* gfs2_releasepage - free the metadata associated with a page
* @page: the page that's being released
@@ -1194,7 +1098,7 @@ static const struct address_space_operations gfs2_writeback_aops = {
.bmap = gfs2_bmap,
.invalidatepage = gfs2_invalidatepage,
.releasepage = gfs2_releasepage,
.direct_IO = gfs2_direct_IO,
.direct_IO = noop_direct_IO,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
@@ -1211,7 +1115,7 @@ static const struct address_space_operations gfs2_ordered_aops = {
.bmap = gfs2_bmap,
.invalidatepage = gfs2_invalidatepage,
.releasepage = gfs2_releasepage,
.direct_IO = gfs2_direct_IO,
.direct_IO = noop_direct_IO,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,