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path: root/fs/nilfs2/cpfile.h
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2009-06-10nilfs2: allow future expansion of metadata read out via get info ioctlRyusuke Konishi
Nilfs has some ioctl commands to read out metadata from meta data files: - NILFS_IOCTL_GET_CPINFO for checkpoint file, - NILFS_IOCTL_GET_SUINFO for segment usage file, and - NILFS_IOCTL_GET_VINFO for Disk Address Transalation (DAT) file, respectively. Every routine on these metadata files is implemented so that it allows future expansion of on-disk format. But, the above ioctl commands do not support expansion even though nilfs_argv structure can handle arbitrary size for data exchanged via ioctl. This allows future expansion of the following structures which give basic format of the "get information" ioctls: - struct nilfs_cpinfo - struct nilfs_suinfo - struct nilfs_vinfo So, this introduces forward compatility of such ioctl commands. In this patch, a sanity check in nilfs_ioctl_get_info() function is changed to accept larger data structure [1], and metadata read routines are rewritten so that they become compatible for larger structures; the routines will just ignore the remaining fields which the current version of nilfs doesn't know. [1] The ioctl function already has another upper limit (PAGE_SIZE against a structure, which appears in nilfs_ioctl_wrap_copy function), and this will not cause security problem. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-04-07nilfs2: fix gc failure on volumes keeping numerous snapshotsRyusuke Konishi
This resolves the following failure of nilfs2 cleaner daemon: nilfs_cleanerd[20670]: cannot clean segments: No such file or directory nilfs_cleanerd[20670]: shutdown When creating thousands of snapshots, the cleaner daemon had rarely died as above due to an error returned from the kernel code. After applying the recent patch which fixed memory allocation problems in ioctl (Message-Id: <20081215.155840.105124170.ryusuke@osrg.net>), the problem gets more frequent. It turned out to be a bug of nilfs_ioctl_wrap_copy function and one of its callback routines to read out information of snapshots; if the nilfs_ioctl_wrap_copy function divided a large read request into multiple requests, the second and later requests have failed since a restart position on snapshot meta data was not properly set forward. It's a deficiency of the callback interface that cannot pass the restart position among multiple requests. This patch fixes the issue by allowing nilfs_ioctl_wrap_copy and snapshot read functions to exchange a position argument. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07nilfs2: checkpoint fileKoji Sato
This adds a meta data file which holds checkpoint entries in its data blocks. Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>