The following patches propose an implementation of project quota support for ext4. A project is an aggregate of unrelated inodes which might scatter in different directories. Inodes belongs to a project possesses a same identification i.e. 'project ID', just like every inode has its user/group identification. The following patches adds project quota as supplement to the former uer/group quota types. The semantics of ext4 project quota is consistent with XFS. Each directory can have EXT4_INODE_PROJINHERIT flag set. When the EXT4_INODE_PROJINHERIT flag of a parent directory is not set, a newly created inode under that directory will have a default project ID (i.e. 0). And its EXT4_INODE_PROJINHERIT flag is not set either. When this flag is set on a directory, following rules will be kept: 1) The newly created inode under that directory will inherit both the EXT4_INODE_PROJINHERIT flag and the project ID from its parent directory. 2) Hard-linking a inode with different project ID into that directory will fail with errno EXDEV. 3) Renaming a inode with different project ID into that directory will fail with errno EXDEV. However, 'mv' command will detect this failure and copy the renamed inode to a new inode in the directory. Thus, this new inode will inherit both the project ID and EXT4_INODE_PROJINHERIT flag. 4) If the project quota of that ID is being enforced, statfs() on that directory will take the quotas as another upper limits along with the capacity of the file system, i.e. the total block/inode number will be the minimum of the quota limits and file system capacity. Changelog: * v4 <- v3: - Do not check project feature when set/get project ID; - Use EXT4_MAXQUOTAS instead of MAXQUOTAS in ext4 patches; - Remove unnecessary change of fs/quota/dquot.c; - Remove CONFIG_QUOTA_PROJECT. * v3 <- v2: - Add EXT4_INODE_PROJINHERIT semantics. * v2 <- v1: - Add ioctl interface for setting/getting project; - Add EXT4_FEATURE_RO_COMPAT_PROJECT; - Add get_projid() method in struct dquot_operations; - Add error check of ext4_inode_projid_set/get(). v3: http://www.spinics.net/lists/linux-ext4/msg45184.html v2: http://www.spinics.net/lists/linux-ext4/msg44695.html v1: http://article.gmane.org/gmane.comp.file-systems.ext4/45153 Any comments or feedbacks are appreciated. Regards, - Li Xi Li Xi (4): Adds general codes to enforces project quota limits Adds project ID support for ext4 Adds project quota support for ext4 Adds ioctl interface support for ext4 project Documentation/filesystems/ext4.txt | 4 + fs/ext4/ext4.h | 31 +++++++-- fs/ext4/ialloc.c | 6 ++ fs/ext4/inode.c | 29 ++++++++- fs/ext4/ioctl.c | 85 ++++++++++++++++++++++++ fs/ext4/namei.c | 10 +++ fs/ext4/super.c | 124 ++++++++++++++++++++++++++++++++--- fs/quota/dquot.c | 16 ++++- fs/quota/quota.c | 5 +- fs/quota/quotaio_v2.h | 6 +- include/linux/quota.h | 2 + include/uapi/linux/quota.h | 6 +- 12 files changed, 299 insertions(+), 25 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
