diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_attr.h')
| -rw-r--r-- | fs/xfs/libxfs/xfs_attr.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h index 2b1f61987a9d..1267ea86ce7a 100644 --- a/fs/xfs/libxfs/xfs_attr.h +++ b/fs/xfs/libxfs/xfs_attr.h @@ -74,6 +74,133 @@ struct xfs_attr_list_context { }; +/* + * ======================================================================== + * Structure used to pass context around among the delayed routines. + * ======================================================================== + */ + +/* + * Below is a state machine diagram for attr remove operations. The XFS_DAS_* + * states indicate places where the function would return -EAGAIN, and then + * immediately resume from after being called by the calling function. States + * marked as a "subroutine state" indicate that they belong to a subroutine, and + * so the calling function needs to pass them back to that subroutine to allow + * it to finish where it left off. But they otherwise do not have a role in the + * calling function other than just passing through. + * + * xfs_attr_remove_iter() + * │ + * v + * have attr to remove? ──n──> done + * │ + * y + * │ + * v + * are we short form? ──y──> xfs_attr_shortform_remove ──> done + * │ + * n + * │ + * V + * are we leaf form? ──y──> xfs_attr_leaf_removename ──> done + * │ + * n + * │ + * V + * ┌── need to setup state? + * │ │ + * n y + * │ │ + * │ v + * │ find attr and get state + * │ attr has remote blks? ──n─┐ + * │ │ v + * │ │ find and invalidate + * │ y the remote blocks. + * │ │ mark attr incomplete + * │ ├────────────────┘ + * └──────────┤ + * │ + * v + * Have remote blks to remove? ───y─────┐ + * │ ^ remove the blks + * │ │ │ + * │ │ v + * │ XFS_DAS_RMTBLK <─n── done? + * │ re-enter with │ + * │ one less blk to y + * │ remove │ + * │ V + * │ refill the state + * n │ + * │ v + * │ XFS_DAS_RM_NAME + * │ │ + * ├─────────────────────────┘ + * │ + * v + * remove leaf and + * update hash with + * xfs_attr_node_remove_cleanup + * │ + * v + * need to + * shrink tree? ─n─┐ + * │ │ + * y │ + * │ │ + * v │ + * join leaf │ + * │ │ + * v │ + * XFS_DAS_RM_SHRINK │ + * │ │ + * v │ + * do the shrink │ + * │ │ + * v │ + * free state <──┘ + * │ + * v + * done + * + */ + +/* + * Enum values for xfs_delattr_context.da_state + * + * These values are used by delayed attribute operations to keep track of where + * they were before they returned -EAGAIN. A return code of -EAGAIN signals the + * calling function to roll the transaction, and then call the subroutine to + * finish the operation. The enum is then used by the subroutine to jump back + * to where it was and resume executing where it left off. + */ +enum xfs_delattr_state { + XFS_DAS_UNINIT = 0, /* No state has been set yet */ + XFS_DAS_RMTBLK, /* Removing remote blks */ + XFS_DAS_RM_NAME, /* Remove attr name */ + XFS_DAS_RM_SHRINK, /* We are shrinking the tree */ +}; + +/* + * Defines for xfs_delattr_context.flags + */ +#define XFS_DAC_DEFER_FINISH 0x01 /* finish the transaction */ + +/* + * Context used for keeping track of delayed attribute operations + */ +struct xfs_delattr_context { + struct xfs_da_args *da_args; + + /* Used in xfs_attr_node_removename to roll through removing blocks */ + struct xfs_da_state *da_state; + + /* Used to keep track of current state of delayed operation */ + unsigned int flags; + enum xfs_delattr_state dela_state; +}; + /*======================================================================== * Function prototypes for the kernel. *========================================================================*/ @@ -92,6 +219,10 @@ int xfs_attr_set(struct xfs_da_args *args); int xfs_attr_set_args(struct xfs_da_args *args); int xfs_has_attr(struct xfs_da_args *args); int xfs_attr_remove_args(struct xfs_da_args *args); +int xfs_attr_remove_iter(struct xfs_delattr_context *dac); +int xfs_attr_trans_roll(struct xfs_delattr_context *dac); bool xfs_attr_namecheck(const void *name, size_t length); +void xfs_delattr_context_init(struct xfs_delattr_context *dac, + struct xfs_da_args *args); #endif /* __XFS_ATTR_H__ */ |