From: Mike Christie Date: Fri, 3 Jun 2016 01:12:37 +0000 (-0500) Subject: target: Fix max_unmap_lba_count calc overflow X-Git-Tag: v3.14.77~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=034668ac914f360ac300d56d4cb80f2b919852fa;p=thirdparty%2Fkernel%2Fstable.git target: Fix max_unmap_lba_count calc overflow commit ea263c7fada4af8ec7fe5fcfd6e7d7705a89351b upstream. max_discard_sectors only 32bits, and some non scsi backend devices will set this to the max 0xffffffff, so we can end up overflowing during the max_unmap_lba_count calculation. This fixes a regression caused by my patch: commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3 Author: Mike Christie Date: Mon Jan 18 14:09:27 2016 -0600 target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors which can result in extra discards being sent to due the overflow causing max_unmap_lba_count to be smaller than what the backing device can actually support. Signed-off-by: Mike Christie Reviewed-by: Bart Van Assche Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index e366b812f0e14..7c3ba7d711f10 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -1583,13 +1583,15 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) * in ATA and we need to set TPE=1 */ bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib, - struct request_queue *q, int block_size) + struct request_queue *q) { + int block_size = queue_logical_block_size(q); + if (!blk_queue_discard(q)) return false; - attrib->max_unmap_lba_count = (q->limits.max_discard_sectors << 9) / - block_size; + attrib->max_unmap_lba_count = + q->limits.max_discard_sectors >> (ilog2(block_size) - 9); /* * Currently hardcoded to 1 in Linux/SCSI code.. */ diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index 6fe5b503f6e17..d8bf1d9c723d9 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -165,8 +165,7 @@ static int fd_configure_device(struct se_device *dev) dev_size, div_u64(dev_size, fd_dev->fd_block_size), fd_dev->fd_block_size); - if (target_configure_unmap_from_queue(&dev->dev_attrib, q, - fd_dev->fd_block_size)) + if (target_configure_unmap_from_queue(&dev->dev_attrib, q)) pr_debug("IFILE: BLOCK Discard support available," " disabled by default\n"); /* diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index 357b9fb614990..f66e677ee5e52 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -126,8 +126,7 @@ static int iblock_configure_device(struct se_device *dev) dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q); dev->dev_attrib.hw_queue_depth = q->nr_requests; - if (target_configure_unmap_from_queue(&dev->dev_attrib, q, - dev->dev_attrib.hw_block_size)) + if (target_configure_unmap_from_queue(&dev->dev_attrib, q)) pr_debug("IBLOCK: BLOCK Discard support available," " disabled by default\n"); diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index 522ae25a61a70..c519c126ee14e 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -96,6 +96,6 @@ void array_free(void *array, int n); sector_t target_to_linux_sector(struct se_device *dev, sector_t lb); bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib, - struct request_queue *q, int block_size); + struct request_queue *q); #endif /* TARGET_CORE_BACKEND_H */