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authorAndreas Gruenbacher <agruenba@redhat.com>2018-07-24 20:02:40 +0200
committerAndreas Gruenbacher <agruenba@redhat.com>2018-07-24 20:02:40 +0200
commita3479c7fc096a1a7a2dccbfbdc6fcf86b805711a (patch)
tree85b0044b207d05b0cf5f118f2160a8de996073ce /fs/gfs2/file.c
parent109dbb1e6f27fb8f80ee61953485c7c3b1717951 (diff)
parent025d0e7f73c6a9cc3ca2fe7de821792a8f3269bf (diff)
Merge branch 'iomap-write' into linux-gfs2/for-next
Pull in the gfs2 iomap-write changes: Tweak the existing code to properly support iomap write and eliminate an unnecessary special case in gfs2_block_map. Implement iomap write support for buffered and direct I/O. Simplify some of the existing code and eliminate code that is no longer used: gfs2: Remove gfs2_write_{begin,end} gfs2: iomap direct I/O support gfs2: gfs2_extent_length cleanup gfs2: iomap buffered write support gfs2: Further iomap cleanups This is based on the following changes on the xfs 'iomap-4.19-merge' branch: iomap: add private pointer to struct iomap iomap: add a page_done callback iomap: generic inline data handling iomap: complete partial direct I/O writes synchronously iomap: mark newly allocated buffer heads as new fs: factor out a __generic_write_end helper Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2/file.c')
-rw-r--r--fs/gfs2/file.c162
1 files changed, 153 insertions, 9 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 8cb278ee9a0e..f3c6d78659b1 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -26,10 +26,12 @@
#include <linux/dlm.h>
#include <linux/dlm_plock.h>
#include <linux/delay.h>
+#include <linux/backing-dev.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
+#include "aops.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
@@ -688,12 +690,89 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
return ret ? ret : ret1;
}
+static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *file = iocb->ki_filp;
+ struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
+ size_t count = iov_iter_count(to);
+ struct gfs2_holder gh;
+ ssize_t ret;
+
+ if (!count)
+ return 0; /* skip atime */
+
+ gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
+ ret = gfs2_glock_nq(&gh);
+ if (ret)
+ goto out_uninit;
+
+ /* fall back to buffered I/O for stuffed files */
+ ret = -ENOTBLK;
+ if (gfs2_is_stuffed(ip))
+ goto out;
+
+ ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL);
+
+out:
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ return ret;
+}
+
+static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct gfs2_inode *ip = GFS2_I(inode);
+ size_t len = iov_iter_count(from);
+ loff_t offset = iocb->ki_pos;
+ struct gfs2_holder gh;
+ ssize_t ret;
+
+ /*
+ * Deferred lock, even if its a write, since we do no allocation on
+ * this path. All we need to change is the 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);
+ ret = gfs2_glock_nq(&gh);
+ if (ret)
+ goto out_uninit;
+
+ /* Silently fall back to buffered I/O when writing beyond EOF */
+ if (offset + len > i_size_read(&ip->i_inode))
+ goto out;
+
+ ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL);
+
+out:
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ return ret;
+}
+
+static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ ssize_t ret;
+
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ ret = gfs2_file_direct_read(iocb, to);
+ if (likely(ret != -ENOTBLK))
+ return ret;
+ iocb->ki_flags &= ~IOCB_DIRECT;
+ }
+ return generic_file_read_iter(iocb, to);
+}
+
/**
* gfs2_file_write_iter - Perform a write to a file
* @iocb: The io context
- * @iov: The data to write
- * @nr_segs: Number of @iov segments
- * @pos: The file position
+ * @from: The data to write
*
* We have to do a lock/unlock here to refresh the inode size for
* O_APPEND writes, otherwise we can land up writing at the wrong
@@ -705,8 +784,9 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
- struct gfs2_inode *ip = GFS2_I(file_inode(file));
- int ret;
+ struct inode *inode = file_inode(file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ ssize_t written = 0, ret;
ret = gfs2_rsqa_alloc(ip);
if (ret)
@@ -723,7 +803,71 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
gfs2_glock_dq_uninit(&gh);
}
- return generic_file_write_iter(iocb, from);
+ inode_lock(inode);
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out;
+
+ /* We can write back this queue in page reclaim */
+ current->backing_dev_info = inode_to_bdi(inode);
+
+ ret = file_remove_privs(file);
+ if (ret)
+ goto out2;
+
+ ret = file_update_time(file);
+ if (ret)
+ goto out2;
+
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ struct address_space *mapping = file->f_mapping;
+ loff_t pos, endbyte;
+ ssize_t buffered;
+
+ written = gfs2_file_direct_write(iocb, from);
+ if (written < 0 || !iov_iter_count(from))
+ goto out2;
+
+ ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
+ if (unlikely(ret < 0))
+ goto out2;
+ buffered = ret;
+
+ /*
+ * We need to ensure that the page cache pages are written to
+ * disk and invalidated to preserve the expected O_DIRECT
+ * semantics.
+ */
+ pos = iocb->ki_pos;
+ endbyte = pos + buffered - 1;
+ ret = filemap_write_and_wait_range(mapping, pos, endbyte);
+ if (!ret) {
+ iocb->ki_pos += buffered;
+ written += buffered;
+ invalidate_mapping_pages(mapping,
+ pos >> PAGE_SHIFT,
+ endbyte >> PAGE_SHIFT);
+ } else {
+ /*
+ * We don't know how much we wrote, so just return
+ * the number of bytes which were direct-written
+ */
+ }
+ } else {
+ ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
+ if (likely(ret > 0))
+ iocb->ki_pos += ret;
+ }
+
+out2:
+ current->backing_dev_info = NULL;
+out:
+ inode_unlock(inode);
+ if (likely(ret > 0)) {
+ /* Handle various SYNC-type writes */
+ ret = generic_write_sync(iocb, ret);
+ }
+ return written ? written : ret;
}
static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
@@ -754,7 +898,7 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
if (error)
goto out;
offset = iomap.offset + iomap.length;
- if (iomap.type != IOMAP_HOLE)
+ if (!(iomap.flags & IOMAP_F_NEW))
continue;
error = sb_issue_zeroout(sb, iomap.addr >> inode->i_blkbits,
iomap.length >> inode->i_blkbits,
@@ -1125,7 +1269,7 @@ static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
const struct file_operations gfs2_file_fops = {
.llseek = gfs2_llseek,
- .read_iter = generic_file_read_iter,
+ .read_iter = gfs2_file_read_iter,
.write_iter = gfs2_file_write_iter,
.unlocked_ioctl = gfs2_ioctl,
.mmap = gfs2_mmap,
@@ -1155,7 +1299,7 @@ const struct file_operations gfs2_dir_fops = {
const struct file_operations gfs2_file_fops_nolock = {
.llseek = gfs2_llseek,
- .read_iter = generic_file_read_iter,
+ .read_iter = gfs2_file_read_iter,
.write_iter = gfs2_file_write_iter,
.unlocked_ioctl = gfs2_ioctl,
.mmap = gfs2_mmap,