JBD2_JOURNAL_EXTEND(9)              The Linux Journalling API              JBD2_JOURNAL_EXTEND(9)



NAME
       jbd2_journal_extend - extend buffer credits.

SYNOPSIS
       int jbd2_journal_extend(handle_t * handle, int nblocks);

ARGUMENTS
       handle
           handle to 'extend'

       nblocks
           nr blocks to try to extend by.

DESCRIPTION
       Some transactions, such as large extends and truncates, can be done atomically all at once
       or in several stages. The operation requests a credit for a number of buffer modifications
       in advance, but can extend its credit if it needs more.

       jbd2_journal_extend tries to give the running handle more buffer credits. It does not
       guarantee that allocation - this is a best-effort only. The calling process MUST be able
       to deal cleanly with a failure to extend here.

       Return 0 on success, non-zero on failure.

       return code < 0 implies an error return code > 0 implies normal transaction-full status.

AUTHORS
       Roger Gammans <rgammans AT computer-surgery.uk>
           Author.

       Stephen Tweedie <sct AT redhat.com>
           Author.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                    JBD2_JOURNAL_EXTEND(9)