LinuxQuestions.org - How to determine name of file which owns a block number on a FS?

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How to determine name of file which owns a block number on a FS?

I need to monitor file reads&writes by all the apps. I have found a kernel feature /proc/sys/vm/block_dump. But it only gives me block numbers while i would like to know file names. How can i convert these block numbers to file names (if the blocks belong to a file, of course)?

Quote:

Originally Posted by 10110111 (Post 3946311)

How can i convert these block numbers to file names (if the blocks belong to a file, of course)?

Code:

# asserting ext file-system:

# for b_block

BLOCKNR="4000001"

# the inode is

INODE=$(echo "icheck ${BLOCKNR}"|debugfs /dev/devicename 2>/dev/null| awk '/^[0-9]/ {print $2}')

# which translates to file

FILENAME=$(find /mountpoint -inum "${INODE}" 2>/dev/null)

Quote:

Originally Posted by 10110111 (Post 3946311)

I need to monitor file reads&writes by all the apps.

Using the above kludge is WAY SLOW. To be able to suggest possible other methods please tell us: why do you need to track all reads and writes? And why for all applications?

Quote:

why do you need to track all reads and writes? And why for all applications?

I'm trying to understand why my desktop starts so slow. As i see, all the time hard drive is busy while startup. So, i decided to look what files access needs to be optimised.
strace will not suffice for this (and it would be even more hard to convert file handles in read()/write() to file names).

Why not try ready-made tools like http://www.bootchart.org/ first?