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author | Damien Le Moal <damien.lemoal@opensource.wdc.com> | 2023-03-29 13:16:01 +0900 |
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committer | Damien Le Moal <damien.lemoal@opensource.wdc.com> | 2023-03-30 20:55:49 +0900 |
commit | c1976bd8f23016d8706973908f2bb0ac0d852a8f (patch) | |
tree | 84c1ffa6bbd37a37db5cc45e957320a56d5d77f2 /fs/zonefs | |
parent | 197b6b60ae7bc51dd0814953c562833143b292aa (diff) | |
download | lwn-c1976bd8f23016d8706973908f2bb0ac0d852a8f.tar.gz lwn-c1976bd8f23016d8706973908f2bb0ac0d852a8f.zip |
zonefs: Always invalidate last cached page on append write
When a direct append write is executed, the append offset may correspond
to the last page of a sequential file inode which might have been cached
already by buffered reads, page faults with mmap-read or non-direct
readahead. To ensure that the on-disk and cached data is consistant for
such last cached page, make sure to always invalidate it in
zonefs_file_dio_append(). If the invalidation fails, return -EBUSY to
userspace to differentiate from IO errors.
This invalidation will always be a no-op when the FS block size (device
zone write granularity) is equal to the page size (e.g. 4K).
Reported-by: Hans Holmberg <Hans.Holmberg@wdc.com>
Fixes: 02ef12a663c7 ("zonefs: use REQ_OP_ZONE_APPEND for sync DIO")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Diffstat (limited to 'fs/zonefs')
-rw-r--r-- | fs/zonefs/file.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c index 617e4f9db42e..c6ab2732955e 100644 --- a/fs/zonefs/file.c +++ b/fs/zonefs/file.c @@ -382,6 +382,7 @@ static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from) struct zonefs_zone *z = zonefs_inode_zone(inode); struct block_device *bdev = inode->i_sb->s_bdev; unsigned int max = bdev_max_zone_append_sectors(bdev); + pgoff_t start, end; struct bio *bio; ssize_t size = 0; int nr_pages; @@ -390,6 +391,19 @@ static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from) max = ALIGN_DOWN(max << SECTOR_SHIFT, inode->i_sb->s_blocksize); iov_iter_truncate(from, max); + /* + * If the inode block size (zone write granularity) is smaller than the + * page size, we may be appending data belonging to the last page of the + * inode straddling inode->i_size, with that page already cached due to + * a buffered read or readahead. So make sure to invalidate that page. + * This will always be a no-op for the case where the block size is + * equal to the page size. + */ + start = iocb->ki_pos >> PAGE_SHIFT; + end = (iocb->ki_pos + iov_iter_count(from) - 1) >> PAGE_SHIFT; + if (invalidate_inode_pages2_range(inode->i_mapping, start, end)) + return -EBUSY; + nr_pages = iov_iter_npages(from, BIO_MAX_VECS); if (!nr_pages) return 0; |