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Message-Id: <1408031441-31156-8-git-send-email-ming.lei@canonical.com> Date: Thu, 14 Aug 2014 23:50:38 +0800 From: Ming Lei <ming.lei@...onical.com> To: Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org, Andrew Morton <akpm@...ux-foundation.org>, Dave Kleikamp <dave.kleikamp@...cle.com> Cc: Zach Brown <zab@...bo.net>, Benjamin LaHaise <bcrl@...ck.org>, Christoph Hellwig <hch@...radead.org>, Kent Overstreet <kmo@...erainc.com>, linux-aio@...ck.org, linux-fsdevel@...r.kernel.org, Dave Chinner <david@...morbit.com>, Ming Lei <ming.lei@...onical.com> Subject: [PATCH v1 7/9] block: loop: introduce lo_discard() and lo_req_flush() No behaviour change, just move the handling for REQ_DISCARD and REQ_FLUSH in these two functions. Signed-off-by: Ming Lei <ming.lei@...onical.com> --- drivers/block/loop.c | 73 +++++++++++++++++++++++++++----------------------- 1 file changed, 40 insertions(+), 33 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index ad43d4b..3836dcc 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -417,6 +417,40 @@ lo_receive(struct loop_device *lo, struct request *rq, int bsize, loff_t pos) return 0; } +static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos) +{ + /* + * We use punch hole to reclaim the free space used by the + * image a.k.a. discard. However we do not support discard if + * encryption is enabled, because it may give an attacker + * useful information. + */ + struct file *file = lo->lo_backing_file; + int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; + int ret; + + if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) { + ret = -EOPNOTSUPP; + goto out; + } + + ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); + if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) + ret = -EIO; + out: + return ret; +} + +static int lo_req_flush(struct loop_device *lo, struct request *rq) +{ + struct file *file = lo->lo_backing_file; + int ret = vfs_fsync(file, 0); + if (unlikely(ret && ret != -EINVAL)) + ret = -EIO; + + return ret; +} + static int do_req_filebacked(struct loop_device *lo, struct request *rq) { loff_t pos; @@ -425,46 +459,19 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; if (rq->cmd_flags & REQ_WRITE) { - struct file *file = lo->lo_backing_file; - - if (rq->cmd_flags & REQ_FLUSH) { - ret = vfs_fsync(file, 0); - if (unlikely(ret && ret != -EINVAL)) { - ret = -EIO; - goto out; - } - } - /* - * We use punch hole to reclaim the free space used by the - * image a.k.a. discard. However we do not support discard if - * encryption is enabled, because it may give an attacker - * useful information. - */ + if (rq->cmd_flags & REQ_FLUSH) + ret = lo_req_flush(lo, rq); + if (rq->cmd_flags & REQ_DISCARD) { - struct file *file = lo->lo_backing_file; - int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; - - if ((!file->f_op->fallocate) || - lo->lo_encrypt_key_size) { - ret = -EOPNOTSUPP; - goto out; - } - ret = file->f_op->fallocate(file, mode, pos, - blk_rq_bytes(rq)); - if (unlikely(ret && ret != -EINVAL && - ret != -EOPNOTSUPP)) - ret = -EIO; + ret = lo_discard(lo, rq, pos); goto out; } ret = lo_send(lo, rq, pos); - if ((rq->cmd_flags & REQ_FUA) && !ret) { - ret = vfs_fsync(file, 0); - if (unlikely(ret && ret != -EINVAL)) - ret = -EIO; - } + if ((rq->cmd_flags & REQ_FUA) && !ret) + ret = lo_req_flush(lo, rq); } else ret = lo_receive(lo, rq, lo->lo_blocksize, pos); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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