[Samsung Galaxy Nexus] zhongfu:
A few days ago, I noticed my phone started displaying the SIM unlock menu in the morning. Later, I saw it reboot all of a sudden, and so I left it to observe for a bit more. The random reboots continued, so I rebackuped everything in TiBu, did a factory reset (wipe /data without /sdcard, /cache and dalvik cache) and updated the ROM I was using.

The reboots were still there, so I copied out all the data, suspecting corruption. My phone rebooted halfway through copying the files so I did it again in recovery. Then, I ran fastboot -w and rebooted into TWRP. It asked for an encryption password, and after doing a factory reset and rebooting it still did. Booting normally and then rebooting into TWRP fixed that.

After that, I went back ingo TWRP and used adb to push the sdcard files back in. Halfway through, adb gave me an error:

failed to copy './DCIM/Camera/IMG_20130121_174846.jpg' to '/sdcard/DCIM/Camera/IMG_20130121_174846.jpg': Read-only file system

I tried again and the same thing happened. I decided to look in dmesg, and lo and behold:

......
<3>[ 1232.192260] end_request: I/O error, dev mmcblk0, sector 5539768
<3>[ 1232.192443] end_request: I/O error, dev mmcblk0, sector 5539776
<3>[ 1232.192749] end_request: I/O error, dev mmcblk0, sector 5539784
<3>[ 1232.192932] end_request: I/O error, dev mmcblk0, sector 5539792
<3>[ 1232.193267] end_request: I/O error, dev mmcblk0, sector 5539800
<3>[ 1232.193420] end_request: I/O error, dev mmcblk0, sector 5539808
<3>[ 1232.193756] end_request: I/O error, dev mmcblk0, sector 5539816
<3>[ 1232.193939] end_request: I/O error, dev mmcblk0, sector 5539824
<3>[ 1232.194244] end_request: I/O error, dev mmcblk0, sector 5539832
<3>[ 1232.194580] Buffer I/O error on device mmcblk0p12, logical block 394880
<3>[ 1232.194793] Buffer I/O error on device mmcblk0p12, logical block 394881
<3>[ 1232.195129] Buffer I/O error on device mmcblk0p12, logical block 394882
<3>[ 1232.195312] Buffer I/O error on device mmcblk0p12, logical block 394883
<3>[ 1232.195648] Buffer I/O error on device mmcblk0p12, logical block 394884
<3>[ 1232.195861] Buffer I/O error on device mmcblk0p12, logical block 394885
<3>[ 1232.196197] Buffer I/O error on device mmcblk0p12, logical block 394886
<3>[ 1232.196533] Buffer I/O error on device mmcblk0p12, logical block 394887
<3>[ 1232.196716] Buffer I/O error on device mmcblk0p12, logical block 394888
<3>[ 1232.197052] Buffer I/O error on device mmcblk0p12, logical block 394889
......
<3>[ 1275.397430] Buffer I/O error on device mmcblk0p12, logical block 2600935
<3>[ 1275.397491] Buffer I/O error on device mmcblk0p12, logical block 2600936
<4>[ 1275.397613] EXT4-fs warning (device mmcblk0p12): ext4_end_bio:258: I/O error writing to inode 643562 (offset 1572864 size 524288 starting block 2898409)
<4>[ 1275.479003] JBD2: Detected IO errors while flushing file data on mmcblk0p12-8
......
<3>[ 1529.202911] mmcblk0: timed out sending r/w cmd command, card status 0x900
<3>[ 1529.203247] mmcblk0: not retrying timeout
<3>[ 1529.203430] end_request: I/O error, dev mmcblk0, sector 2425376
<3>[ 1529.203765] end_request: I/O error, dev mmcblk0, sector 2425384
<3>[ 1529.203979] end_request: I/O error, dev mmcblk0, sector 2425392
<3>[ 1529.204284] end_request: I/O error, dev mmcblk0, sector 2425400
<3>[ 1529.204620] end_request: I/O error, dev mmcblk0, sector 2425408
<3>[ 1529.204803] end_request: I/O error, dev mmcblk0, sector 2425416
<3>[ 1529.205139] end_request: I/O error, dev mmcblk0, sector 2425424
<3>[ 1529.205322] end_request: I/O error, dev mmcblk0, sector 2425432
<3>[ 1529.205627] end_request: I/O error, dev mmcblk0, sector 2425440
<3>[ 1529.205993] Aborting journal on device mmcblk0p12-8.
<2>[ 1529.206420] EXT4-fs error (device mmcblk0p12) in ext4_reserve_inode_write:5654: Journal has aborted
<2>[ 1529.216522] EXT4-fs (mmcblk0p12): Remounting filesystem read-only

What should I do now?