From 5c211caa9f341f9eefbda89436d1440d1eccb3bc Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 18 Feb 2009 10:54:44 -0500 Subject: [PATCH] [SCSI] sd: tell the user when a disk's capacity is adjusted This patch (as1188) combines the tests for decrementing a drive's reported capacity and expands the comment. It also adds an informational message to the system log, informing the user when the reported value has been changed. Signed-off-by: Alan Stern Signed-off-by: James Bottomley --- drivers/scsi/sd.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 4970ae4a62d..e744ee40be6 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1383,18 +1383,22 @@ repeat: sd_read_protection_type(sdkp, buffer); } - /* Some devices return the total number of sectors, not the - * highest sector number. Make the necessary adjustment. */ - if (sdp->fix_capacity) { + /* Some devices are known to return the total number of blocks, + * not the highest block number. Some devices have versions + * which do this and others which do not. Some devices we might + * suspect of doing this but we don't know for certain. + * + * If we know the reported capacity is wrong, decrement it. If + * we can only guess, then assume the number of blocks is even + * (usually true but not always) and err on the side of lowering + * the capacity. + */ + if (sdp->fix_capacity || + (sdp->guess_capacity && (sdkp->capacity & 0x01))) { + sd_printk(KERN_INFO, sdkp, "Adjusting the sector count " + "from its reported value: %llu\n", + (unsigned long long) sdkp->capacity); --sdkp->capacity; - - /* Some devices have version which report the correct sizes - * and others which do not. We guess size according to a heuristic - * and err on the side of lowering the capacity. */ - } else { - if (sdp->guess_capacity) - if (sdkp->capacity & 0x01) /* odd sizes are odd */ - --sdkp->capacity; } got_data: