3.11.10.3 -stable review patch. If anyone has any objections, please let me know.
------------------ From: majianpeng <[email protected]> commit 02ae66d8b229708fd94b764f6c17ead1c7741fcf upstream. cephfs . show_layout >layyout.data_pool: 0 >layout.object_size: 4194304 >layout.stripe_unit: 4194304 >layout.stripe_count: 1 TestA: >dd if=/dev/urandom of=test bs=1M count=2 oflag=direct >dd if=/dev/urandom of=test bs=1M count=2 seek=4 oflag=direct >dd if=test of=/dev/null bs=6M count=1 iflag=direct The messages from func striped_read are: ceph: file.c:350 : striped_read 0~6291456 (read 0) got 2097152 HITSTRIPE SHORT ceph: file.c:350 : striped_read 2097152~4194304 (read 2097152) got 0 HITSTRIPE SHORT ceph: file.c:381 : zero tail 4194304 ceph: file.c:390 : striped_read returns 6291456 The hole of file is from 2M--4M.But actualy it zero the last 4M include the last 2M area which isn't a hole. Using this patch, the messages are: ceph: file.c:350 : striped_read 0~6291456 (read 0) got 2097152 HITSTRIPE SHORT ceph: file.c:358 : zero gap 2097152 to 4194304 ceph: file.c:350 : striped_read 4194304~2097152 (read 4194304) got 2097152 ceph: file.c:384 : striped_read returns 6291456 TestB: >echo majianpeng > test >dd if=test of=/dev/null bs=2M count=1 iflag=direct The messages are: ceph: file.c:350 : striped_read 0~6291456 (read 0) got 11 HITSTRIPE SHORT ceph: file.c:350 : striped_read 11~6291445 (read 11) got 0 HITSTRIPE SHORT ceph: file.c:390 : striped_read returns 11 For this case,it did once more striped_read.It's no meaningless. Using this patch, the message are: ceph: file.c:350 : striped_read 0~6291456 (read 0) got 11 HITSTRIPE SHORT ceph: file.c:384 : striped_read returns 11 Big thanks to Yan Zheng for the patch. Reviewed-by: Yan, Zheng <[email protected]> Signed-off-by: Jianpeng Ma <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- fs/ceph/file.c | 39 ++++++++++++++++----------------------- 1 file changed, 16 insertions(+), 23 deletions(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 93e53c8..5f3b4ee 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -349,44 +349,37 @@ more: dout("striped_read %llu~%llu (read %u) got %d%s%s\n", pos, left, read, ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : ""); - if (ret > 0) { - int didpages = (page_align + ret) >> PAGE_CACHE_SHIFT; - - if (read < pos - off) { - dout(" zero gap %llu to %llu\n", off + read, pos); - ceph_zero_page_vector_range(page_align + read, - pos - off - read, pages); + if (ret >= 0) { + int didpages; + if (was_short && (pos + ret < inode->i_size)) { + u64 tmp = min(this_len - ret, + inode->i_size - pos - ret); + dout(" zero gap %llu to %llu\n", + pos + ret, pos + ret + tmp); + ceph_zero_page_vector_range(page_align + read + ret, + tmp, pages); + ret += tmp; } + + didpages = (page_align + ret) >> PAGE_CACHE_SHIFT; pos += ret; read = pos - off; left -= ret; page_pos += didpages; pages_left -= didpages; - /* hit stripe? */ - if (left && hit_stripe) + /* hit stripe and need continue*/ + if (left && hit_stripe && pos < inode->i_size) goto more; } - if (was_short) { + if (ret >= 0) { + ret = read; /* did we bounce off eof? */ if (pos + left > inode->i_size) *checkeof = 1; - - /* zero trailing bytes (inside i_size) */ - if (left > 0 && pos < inode->i_size) { - if (pos + left > inode->i_size) - left = inode->i_size - pos; - - dout("zero tail %llu\n", left); - ceph_zero_page_vector_range(page_align + read, left, - pages); - read += left; - } } - if (ret >= 0) - ret = read; dout("striped_read returns %d\n", ret); return ret; } -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
