diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_group.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_group.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_group.c b/fs/xfs/libxfs/xfs_group.c new file mode 100644 index 000000000000..e9d76bcdc820 --- /dev/null +++ b/fs/xfs/libxfs/xfs_group.c @@ -0,0 +1,225 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2018 Red Hat, Inc. + */ + +#include "xfs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_error.h" +#include "xfs_trace.h" +#include "xfs_extent_busy.h" +#include "xfs_group.h" + +/* + * Groups can have passive and active references. + * + * For passive references the code freeing a group is responsible for cleaning + * up objects that hold the passive references (e.g. cached buffers). + * Routines manipulating passive references are xfs_group_get, xfs_group_hold + * and xfs_group_put. + * + * Active references are for short term access to the group for walking trees or + * accessing state. If a group is being shrunk or offlined, the lookup will fail + * to find that group and return NULL instead. + * Routines manipulating active references are xfs_group_grab and + * xfs_group_rele. + */ + +struct xfs_group * +xfs_group_get( + struct xfs_mount *mp, + uint32_t index, + enum xfs_group_type type) +{ + struct xfs_group *xg; + + rcu_read_lock(); + xg = xa_load(&mp->m_groups[type].xa, index); + if (xg) { + trace_xfs_group_get(xg, _RET_IP_); + ASSERT(atomic_read(&xg->xg_ref) >= 0); + atomic_inc(&xg->xg_ref); + } + rcu_read_unlock(); + return xg; +} + +struct xfs_group * +xfs_group_hold( + struct xfs_group *xg) +{ + ASSERT(atomic_read(&xg->xg_ref) > 0 || + atomic_read(&xg->xg_active_ref) > 0); + + trace_xfs_group_hold(xg, _RET_IP_); + atomic_inc(&xg->xg_ref); + return xg; +} + +void +xfs_group_put( + struct xfs_group *xg) +{ + trace_xfs_group_put(xg, _RET_IP_); + + ASSERT(atomic_read(&xg->xg_ref) > 0); + atomic_dec(&xg->xg_ref); +} + +struct xfs_group * +xfs_group_grab( + struct xfs_mount *mp, + uint32_t index, + enum xfs_group_type type) +{ + struct xfs_group *xg; + + rcu_read_lock(); + xg = xa_load(&mp->m_groups[type].xa, index); + if (xg) { + trace_xfs_group_grab(xg, _RET_IP_); + if (!atomic_inc_not_zero(&xg->xg_active_ref)) + xg = NULL; + } + rcu_read_unlock(); + return xg; +} + +/* + * Iterate to the next group. To start the iteration at @start_index, a %NULL + * @xg is passed, else the previous group returned from this function. The + * caller should break out of the loop when this returns %NULL. If the caller + * wants to break out of a loop that did not finish it needs to release the + * active reference to @xg using xfs_group_rele() itself. + */ +struct xfs_group * +xfs_group_next_range( + struct xfs_mount *mp, + struct xfs_group *xg, + uint32_t start_index, + uint32_t end_index, + enum xfs_group_type type) +{ + uint32_t index = start_index; + + if (xg) { + index = xg->xg_gno + 1; + xfs_group_rele(xg); + } + if (index > end_index) + return NULL; + return xfs_group_grab(mp, index, type); +} + +/* + * Find the next group after @xg, or the first group if @xg is NULL. + */ +struct xfs_group * +xfs_group_grab_next_mark( + struct xfs_mount *mp, + struct xfs_group *xg, + xa_mark_t mark, + enum xfs_group_type type) +{ + unsigned long index = 0; + + if (xg) { + index = xg->xg_gno + 1; + xfs_group_rele(xg); + } + + rcu_read_lock(); + xg = xa_find(&mp->m_groups[type].xa, &index, ULONG_MAX, mark); + if (xg) { + trace_xfs_group_grab_next_tag(xg, _RET_IP_); + if (!atomic_inc_not_zero(&xg->xg_active_ref)) + xg = NULL; + } + rcu_read_unlock(); + return xg; +} + +void +xfs_group_rele( + struct xfs_group *xg) +{ + trace_xfs_group_rele(xg, _RET_IP_); + atomic_dec(&xg->xg_active_ref); +} + +void +xfs_group_free( + struct xfs_mount *mp, + uint32_t index, + enum xfs_group_type type, + void (*uninit)(struct xfs_group *xg)) +{ + struct xfs_group *xg = xa_erase(&mp->m_groups[type].xa, index); + + XFS_IS_CORRUPT(mp, atomic_read(&xg->xg_ref) != 0); + + xfs_defer_drain_free(&xg->xg_intents_drain); +#ifdef __KERNEL__ + kfree(xg->xg_busy_extents); +#endif + + if (uninit) + uninit(xg); + + /* drop the mount's active reference */ + xfs_group_rele(xg); + XFS_IS_CORRUPT(mp, atomic_read(&xg->xg_active_ref) != 0); + kfree_rcu_mightsleep(xg); +} + +int +xfs_group_insert( + struct xfs_mount *mp, + struct xfs_group *xg, + uint32_t index, + enum xfs_group_type type) +{ + int error; + + xg->xg_mount = mp; + xg->xg_gno = index; + xg->xg_type = type; + +#ifdef __KERNEL__ + xg->xg_busy_extents = xfs_extent_busy_alloc(); + if (!xg->xg_busy_extents) + return -ENOMEM; + spin_lock_init(&xg->xg_state_lock); + xfs_hooks_init(&xg->xg_rmap_update_hooks); +#endif + xfs_defer_drain_init(&xg->xg_intents_drain); + + /* Active ref owned by mount indicates group is online. */ + atomic_set(&xg->xg_active_ref, 1); + + error = xa_insert(&mp->m_groups[type].xa, index, xg, GFP_KERNEL); + if (error) { + WARN_ON_ONCE(error == -EBUSY); + goto out_drain; + } + + return 0; +out_drain: + xfs_defer_drain_free(&xg->xg_intents_drain); +#ifdef __KERNEL__ + kfree(xg->xg_busy_extents); +#endif + return error; +} + +struct xfs_group * +xfs_group_get_by_fsb( + struct xfs_mount *mp, + xfs_fsblock_t fsbno, + enum xfs_group_type type) +{ + return xfs_group_get(mp, xfs_fsb_to_gno(mp, fsbno, type), type); +} |