jbd2_journal_init_dev – creates and initialises a journal structure Synopsis journal_t * jbd2_journal_init_dev(struct block_device * bdev, struct block_device * fs_dev, unsigned long long start, int len, int blocksize); Arguments bdev Block device on which to create the journal fs_dev Device which hold journalled filesystem for this journal. start Block nr Start of journal. len Length of the journal in blocks. blocksize blocksize of…
jbd2_journal_get_write_access – notify intent to modify a buffer for metadata (not data) update. Synopsis int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh); Arguments handle transaction to add buffer modifications to bh bh to be used for metadata writes Description Returns an error code or 0 on success. In full data journalling mode the buffer may be of…
jbd2_journal_get_undo_access – Notify intent to modify metadata with non-rewindable consequences Synopsis int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh); Arguments handle transaction bh buffer to undo Description Sometimes there is a need to distinguish between metadata which has been committed to disk and that which has not. The ext3fs code uses this for freeing and allocating space,…
jbd2_journal_get_create_access – notify intent to use newly created bh Synopsis int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh); Arguments handle transaction to new buffer to bh new buffer. Description Call this if you create a new bh. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie <sct [at] redhat.com> Author. Copyright
jbd2_journal_forget – bforget for potentially-journaled buffers. Synopsis int jbd2_journal_forget(handle_t *handle, struct buffer_head *bh); Arguments handle transaction handle bh bh to ‘forget’ Description We can only do the bforget if there are no commits pending against the buffer. If the buffer is dirty in the current running transaction we can safely unlink it. bh may not…
jbd2_journal_force_commit_nested – Synopsis int jbd2_journal_force_commit_nested(journal_t *journal); Arguments journal journal to force Returns true if progress was made. Description transaction. This is used for forcing out undo-protected data which contains bitmaps, when the fs is running out of space. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie <sct [at] redhat.com> Author. Copyright
jbd2_journal_force_commit – force any uncommitted transactions Synopsis int jbd2_journal_force_commit(journal_t *journal); Arguments journal journal to force Description Caller want unconditional commit. We can only force the running transaction if we don’t have an active handle, otherwise, we will deadlock. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie <sct [at] redhat.com> Author. Copyright
jbd2_journal_flush – Flush journal Synopsis int jbd2_journal_flush(journal_t *journal); Arguments journal Journal to act on. Description Flush all data for a given journal to disk and empty the journal. Filesystems can use this when remounting readonly to ensure that recovery does not need to happen on remount. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie…
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…
jbd2_journal_errno – returns the journal’s error state. Synopsis int jbd2_journal_errno(journal_t *journal); Arguments journal journal to examine. Description This is the errno number set with jbd2_journal_abort, the last time the journal was mounted – if the journal was stopped without calling abort this will be 0. If the journal has been aborted on this mount time…
jbd2_journal_dirty_metadata – mark a buffer as containing dirty metadata Synopsis int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh); Arguments handle transaction to add buffer to. bh buffer to mark Description mark dirty metadata which needs to be journaled as part of the current transaction. The buffer must have previously had jbd2_journal_get_write_access called so that it has a…
jbd2_journal_destroy – Release a journal_t structure. Synopsis int jbd2_journal_destroy(journal_t *journal); Arguments journal Journal to act on. Description Release a journal_t structure once it is no longer in use by the journaled object. Return <0 if we couldn’t clean up the journal. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie <sct [at] redhat.com> Author. Copyright
jbd2_journal_clear_err – clears the journal’s error state Synopsis int jbd2_journal_clear_err(journal_t *journal); Arguments journal journal to act on. Description An error must be cleared or acked to take a FS out of readonly mode. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie <sct [at] redhat.com> Author. Copyright
jbd2_journal_check_used_features – Check if features specified are used. Synopsis int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat, unsigned long ro, unsigned long incompat); Arguments journal Journal to check. compat bitmask of compatible features ro bitmask of features that force read-only mount incompat bitmask of incompatible features Description Check whether the journal uses all of a given set…
jbd2_journal_check_available_features – Check feature set in journalling layer Synopsis int jbd2_journal_check_available_features(journal_t *journal, unsigned long compat, unsigned long ro, unsigned long incompat); Arguments journal Journal to check. compat bitmask of compatible features ro bitmask of features that force read-only mount incompat bitmask of incompatible features Description Check whether the journaling code supports the use of all…
jbd2_journal_ack_err – Ack journal err. Synopsis void jbd2_journal_ack_err(journal_t *journal); Arguments journal journal to act on. Description An error must be cleared or acked to take a FS out of readonly mode. Authors Roger Gammans <rgammans [at] computer-surgery.co.uk> Author. Stephen Tweedie <sct [at] redhat.com> Author. Copyright
jbd2_journal_abort – Shutdown the journal immediately. Synopsis void jbd2_journal_abort(journal_t *journal, int errno); Arguments journal the journal to shutdown. errno an error number to record in the journal indicating the reason for the shutdown. Description Perform a complete, immediate shutdown of the ENTIRE journal (not of a single transaction). This operation cannot be undone without closing…
jbd2__journal_start – Obtain a new handle. Synopsis handle_t * jbd2__journal_start(journal_t * journal, int nblocks, int rsv_blocks, gfp_t gfp_mask, unsigned int type, unsigned int line_no); Arguments journal Journal to start transaction on. nblocks number of block buffer we might modify rsv_blocks — undescribed — gfp_mask — undescribed — type — undescribed — line_no — undescribed — Description We make sure that the transaction…
jbd2__journal_restart – restart a handle . Synopsis int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask); Arguments handle handle to restart nblocks nr credits requested gfp_mask — undescribed — Description Restart a handle for a multi-transaction filesystem operation. If the jbd2_journal_extend call above fails to grant new buffer credits to a running handle, a call to jbd2_journal_restart…
iunique – get a unique inode number Synopsis ino_t iunique(struct super_block * sb, ino_t max_reserved); Arguments sb superblock max_reserved highest reserved inode number Description Obtain an inode number that is unique on the system for a given superblock. This is used by file systems that have no natural permanent inode numbering system. An inode number is returned that…