Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bd2843fe authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

fix ufs write vs readpage race when writing into a hole 



Followup to the UFS series - with the way we clear the new blocks (via
buffer cache, possibly on more than a page worth of file) we really
should not insert a reference to new block into inode block tree until
after we'd cleared it.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent daf0e1ed

fs/ufs/balloc.c

+2 −2
Original line number Diff line number Diff line
@@ -417,14 +417,14 @@ u64 ufs_new_fragments(struct inode *inode, void *p, u64 fragment, 
	if (oldcount == 0) {

		result = ufs_alloc_fragments (inode, cgno, goal, count, err);

		if (result) {

			ufs_clear_frags(inode, result + oldcount,

					newcount - oldcount, locked_page != NULL);

			write_seqlock(&UFS_I(inode)->meta_lock);

			ufs_cpu_to_data_ptr(sb, p, result);

			write_sequnlock(&UFS_I(inode)->meta_lock);

			*err = 0;

			UFS_I(inode)->i_lastfrag =

				max(UFS_I(inode)->i_lastfrag, fragment + count);

			ufs_clear_frags(inode, result + oldcount,

					newcount - oldcount, locked_page != NULL);

		}

		mutex_unlock(&UFS_SB(sb)->s_lock);

		UFSD("EXIT, result %llu\n", (unsigned long long)result);