Comment 3 for bug 809037

I have just started seeing this or a simlar problem on Ubuntu 14.04. Syslog shows that the device has been detected corrected as not being write protected.

Mar 31 19:12:10 dragon kernel: [ 8964.742391] sd 4:0:0:0: [sdb] 61863936 512-byte logical blocks: (31.6 GB/29.4 GiB)
Mar 31 19:12:10 dragon kernel: [ 8964.743608] sd 4:0:0:0: [sdb] Write Protect is off
Mar 31 19:12:10 dragon kernel: [ 8964.743612] sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00
Mar 31 19:12:10 dragon kernel: [ 8964.744731] sd 4:0:0:0: [sdb] No Caching mode page found
Mar 31 19:12:10 dragon kernel: [ 8964.744735] sd 4:0:0:0: [sdb] Assuming drive cache: write through
Mar 31 19:12:10 dragon kernel: [ 8964.747886] sd 4:0:0:0: [sdb] No Caching mode page found
Mar 31 19:12:10 dragon kernel: [ 8964.747891] sd 4:0:0:0: [sdb] Assuming drive cache: write through
Mar 31 19:12:10 dragon kernel: [ 8964.748988] sdb: sdb1
Mar 31 19:12:10 dragon udisksd[2776]: Mounted /dev/sdb1 at /media/roger/Stella on behalf of uid 1000

However /proc/mounts shows that the /dev/sdb1 has been mounted 'ro'. parted reports that the host device /dev/sdb is read only.

/dev/sdb1 /media/roger/Stella vfat ro,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro 0 0

However if I leave the sd card in the reader and reboot then the parition is mounted 'rw', and everything is fine.

Mar 31 19:20:01 dragon kernel: [ 3.534021] sd 4:0:0:0: [sdb] 61863936 512-byte logical blocks: (31.6 GB/29.4 GiB)
Mar 31 19:20:01 dragon kernel: [ 3.534744] sd 4:0:0:1: [sdc] Attached SCSI removable disk
Mar 31 19:20:01 dragon kernel: [ 3.535492] sd 4:0:0:2: [sdd] Attached SCSI removable disk
Mar 31 19:20:01 dragon kernel: [ 3.536291] sd 4:0:0:3: [sde] Attached SCSI removable disk
Mar 31 19:20:01 dragon kernel: [ 3.537354] sd 4:0:0:0: [sdb] Write Protect is off
Mar 31 19:20:01 dragon kernel: [ 3.537359] sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00
Mar 31 19:20:01 dragon kernel: [ 3.538498] sd 4:0:0:0: [sdb] No Caching mode page found
Mar 31 19:20:01 dragon kernel: [ 3.538500] sd 4:0:0:0: [sdb] Assuming drive cache: write through
Mar 31 19:20:01 dragon kernel: [ 3.541768] random: nonblocking pool is initialized
Mar 31 19:20:01 dragon kernel: [ 3.543042] sd 4:0:0:0: [sdb] No Caching mode page found
Mar 31 19:20:01 dragon kernel: [ 3.543047] sd 4:0:0:0: [sdb] Assuming drive cache: write through
Mar 31 19:20:01 dragon kernel: [ 3.544163] sdb: sdb1
Mar 31 19:20:01 dragon kernel: [ 3.548044] sd 4:0:0:0: [sdb] No Caching mode page found
Mar 31 19:20:01 dragon kernel: [ 3.548049] sd 4:0:0:0: [sdb] Assuming drive cache: write through
Mar 31 19:20:01 dragon kernel: [ 3.548052] sd 4:0:0:0: [sdb] Attached SCSI removable disk
...
Mar 31 19:20:38 dragon udisksd[2780]: Mounted /dev/sdb1 at /media/roger/Stella on behalf of uid 1000

Disk shows as mounted 'rw' and evrything is fine!

Roger