[Android Software Development] egingell:
That won't work. If you look at the output of either mount or df, you'll see that there is no mention of the destination directory. One would have to log every execution of the mount command.

These are the actual outputs of both my mount and df commands:

mount

rootfs / rootfs ro,relatime 0 0
tmpfs /dev tmpfs rw,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
tmpfs /mnt/asec tmpfs rw,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,relatime,mode=755,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/mmcblk0p9 /system ext4 ro,noatime,barrier=0,data=ordered 0 0
/dev/block/mmcblk0p7 /cache ext4 rw,nosuid,nodev,noatime,barrier=0,journal_async_commit,data=ordered 0 0
/dev/block/mmcblk0p1 /efs ext4 rw,nosuid,nodev,noatime,barrier=1,journal_async_commit,data=ordered 0 0
/dev/block/mmcblk0p12 /preload ext4 ro,nosuid,nodev,noatime,barrier=0,data=ordered 0 0
/dev/block/mmcblk0p10 /data ext4 rw,nosuid,nodev,noatime,barrier=0,journal_async_commit,data=ordered,noauto_da_alloc,discard 0 0
/dev/block/mmcblk0p4 /mnt/.lfs j4fs rw,relatime 0 0
/sys/kernel/debug /sys/kernel/debug debugfs rw,relatime 0 0
/dev/block/cyasblkdevblk0p2 /data/sdext2 ext4 rw,noatime,barrier=0,data=ordered 0 0

-- Everything below here to 'end' is bound to a matching folder in /data/sdext2 --
/dev/block/cyasblkdevblk0p2 /data/data/com.amazon.venezia/app_resources ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.andrewgarrison.dummydefense/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.andrewgarrison.dummydefense/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.android.chrome/app_chrome ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.android.chrome/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.android.chrome/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.android.providers.contacts/databases ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.ea.game.simpsons4_na/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.ea.game.simpsons4_na/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.facebook.katana/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.facebook.katana/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.facebook.orca/app_sslcache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.facebook.orca/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.facebook.orca/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.google.android.apps.maps/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.google.android.apps.maps/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.google.android.gm/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.keramidas.TitaniumBackupPro/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.keramidas.TitaniumBackupPro/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.ludia.jurassicpark/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.ludia.jurassicpark/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.omgpop.dstpaid/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.omgpop.dstpaid/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.picsart.studio/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.zynga.scramble.paid/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.zynga.scramble.paid/databases ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.zynga.scramble.paid/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.zynga.words/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/com.zynga.words/files ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/opotech.virtualbuttonbar/cache ext4 rw,noatime,barrier=0,data=ordered 0 0
/dev/block/cyasblkdevblk0p2 /data/data/opotech.virtualbuttonbar/files ext4 rw,noatime,barrier=0,data=ordered 0 0
-- end --

/dev/block/vold/259:3 /storage/sdcard0 vfat rw,dirsync,nosuid,nodev,noexec,noatime,nodiratime,uid=1000,gid=1015,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro,discard 0 0
/dev/block/vold/253:1 /storage/extSdCard vfat rw,dirsync,nosuid,nodev,noexec,noatime,nodiratime,uid=1000,gid=1023,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
/dev/block/vold/253:1 /mnt/secure/asec vfat rw,dirsync,nosuid,nodev,noexec,noatime,nodiratime,uid=1000,gid=1023,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
tmpfs /storage/extSdCard/.android_secure tmpfs ro,relatime,size=0k,mode=000 0 0

df

Filesystem Size Used Free Blksize
/dev 400M 76.0K 399M 4096
/mnt/asec 400M 0.00K 400M 4096
/mnt/obb 400M 0.00K 400M 4096
/system 503M 470M 33.0M 4096
/cache 295M 4.88M 290M 4096
/efs 19.7M 4.12M 15.5M 4096
/preload 307M 241M 65.8M 4096
/data 1.97G 604M 1.38G 4096
/data/sdext2 9.37G 951M 8.44G 2048

-- Everything below here to 'end' is bound to a matching folder in /data/sdext2 --
/data/data/com.amazon.venezia/app_resources 9.37G 951M 8.44G 2048
/data/data/com.andrewgarrison.dummydefense/cache 9.37G 951M 8.44G 2048
/data/data/com.andrewgarrison.dummydefense/files 9.37G 951M 8.44G 2048
/data/data/com.android.chrome/app_chrome 9.37G 951M 8.44G 2048
/data/data/com.android.chrome/cache 9.37G 951M 8.44G 2048
/data/data/com.android.chrome/files 9.37G 951M 8.44G 2048
/data/data/com.android.providers.contacts/databases 9.37G 951M 8.44G 2048
/data/data/com.ea.game.simpsons4_na/cache 9.37G 951M 8.44G 2048
/data/data/com.ea.game.simpsons4_na/files 9.37G 951M 8.44G 2048
/data/data/com.facebook.katana/cache 9.37G 951M 8.44G 2048
/data/data/com.facebook.katana/files 9.37G 951M 8.44G 2048
/data/data/com.facebook.orca/app_sslcache 9.37G 951M 8.44G 2048
/data/data/com.facebook.orca/cache 9.37G 951M 8.44G 2048
/data/data/com.facebook.orca/files 9.37G 951M 8.44G 2048
/data/data/com.google.android.apps.maps/cache 9.37G 951M 8.44G 2048
/data/data/com.google.android.apps.maps/files 9.37G 951M 8.44G 2048
/data/data/com.google.android.gm/cache 9.37G 951M 8.44G 2048
/data/data/com.keramidas.TitaniumBackupPro/cache 9.37G 951M 8.44G 2048
/data/data/com.keramidas.TitaniumBackupPro/files 9.37G 951M 8.44G 2048
/data/data/com.ludia.jurassicpark/cache 9.37G 951M 8.44G 2048
/data/data/com.ludia.jurassicpark/files 9.37G 951M 8.44G 2048
/data/data/com.omgpop.dstpaid/cache 9.37G 951M 8.44G 2048
/data/data/com.omgpop.dstpaid/files 9.37G 951M 8.44G 2048
/data/data/com.picsart.studio/cache 9.37G 951M 8.44G 2048
/data/data/com.zynga.scramble.paid/cache 9.37G 951M 8.44G 2048
/data/data/com.zynga.scramble.paid/databases 9.37G 951M 8.44G 2048
/data/data/com.zynga.scramble.paid/files 9.37G 951M 8.44G 2048
/data/data/com.zynga.words/cache 9.37G 951M 8.44G 2048
/data/data/com.zynga.words/files 9.37G 951M 8.44G 2048
/data/data/opotech.virtualbuttonbar/cache 9.37G 951M 8.44G 2048
/data/data/opotech.virtualbuttonbar/files 9.37G 951M 8.44G 2048
-- end --

/storage/sdcard0 11.5G 752M 10.8G 32768
/storage/extSdCard 19.7G 2.30G 17.4G 4096
/mnt/secure/asec 19.7G 2.30G 17.4G 4096

Even /proc/self/mountinfo has ambiguous data: "35 22 253:2 /data/com.facebook.katana/cache /data/data/com.facebook.katana/cache rw,noatime - ext4 /dev/block/cyasblkdevblk0p2 rw,barrier=0,data=ordered" => It appears to be mounted to itself.

/proc/self/mountstats: "device /dev/block/cyasblkdevblk0p2 mounted on /data/data/com.android.chrome/app_chrome with fstype ext4"

Edit: Oh, hey, it *did* post. I spent 5.5 hours of refreshing so I could post this. lol

Edit, again... Hey, wait a minute, I just noticed something in /proc/self/mountinfo. It requires more testing.