[f2fs-dev] [PATCH AUTOSEL 4.19 14/19] f2fs: fix indefinite loop scanning for free nid

[f2fs-dev] [PATCH AUTOSEL 4.19 14/19] f2fs: fix indefinite loop scanning for free nid

[Sasha Levin]

From: Sahitya Tummala <stummala@codeaurora.org>

[ Upstream commit e2cab031ba7b5003cd12185b3ef38f1a75e3dae8 ]

If the sbi->ckpt->next_free_nid is not NAT block aligned and if there
are free nids in that NAT block between the start of the block and
next_free_nid, then those free nids will not be scanned in scan_nat_page().
This results into mismatch between nm_i->available_nids and the sum of
nm_i->free_nid_count of all NAT blocks scanned. And nm_i->available_nids
will always be greater than the sum of free nids in all the blocks.
Under this condition, if we use all the currently scanned free nids,
then it will loop forever in f2fs_alloc_nid() as nm_i->available_nids
is still not zero but nm_i->free_nid_count of that partially scanned
NAT block is zero.

Fix this to align the nm_i->next_scan_nid to the first nid of the
corresponding NAT block.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/node.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 2ff02541c53d5..1934dc6ad1ccd 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -2257,6 +2257,9 @@ static int __f2fs_build_free_nids(struct f2fs_sb_info *sbi,
 	if (unlikely(nid >= nm_i->max_nid))
 		nid = 0;
 
+	if (unlikely(nid % NAT_ENTRY_PER_BLOCK))
+		nid = NAT_BLOCK_OFFSET(nid) * NAT_ENTRY_PER_BLOCK;
+
 	/* Enough entries */
 	if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
 		return 0;
-- 
2.25.1



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[f2fs-dev] [PATCH AUTOSEL 4.19 15/19] f2fs: Return EOF on unaligned end of file DIO read

[Sasha Levin]

From: Gabriel Krisman Bertazi <krisman@collabora.com>

[ Upstream commit 20d0a107fb35f37578b919f62bd474d6d358d579 ]

Reading past end of file returns EOF for aligned reads but -EINVAL for
unaligned reads on f2fs.  While documentation is not strict about this
corner case, most filesystem returns EOF on this case, like iomap
filesystems.  This patch consolidates the behavior for f2fs, by making
it return EOF(0).

it can be verified by a read loop on a file that does a partial read
before EOF (A file that doesn't end at an aligned address).  The
following code fails on an unaligned file on f2fs, but not on
btrfs, ext4, and xfs.

  while (done < total) {
    ssize_t delta = pread(fd, buf + done, total - done, off + done);
    if (!delta)
      break;
    ...
  }

It is arguable whether filesystems should actually return EOF or
-EINVAL, but since iomap filesystems support it, and so does the
original DIO code, it seems reasonable to consolidate on that.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/data.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index c81a1f3f0a101..c63f5e32630ee 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2490,6 +2490,9 @@ static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
 	unsigned long align = offset | iov_iter_alignment(iter);
 	struct block_device *bdev = inode->i_sb->s_bdev;
 
+	if (iov_iter_rw(iter) == READ && offset >= i_size_read(inode))
+		return 1;
+
 	if (align & blocksize_mask) {
 		if (bdev)
 			blkbits = blksize_bits(bdev_logical_block_size(bdev));
-- 
2.25.1



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