From dfd422a38617b6cb769500d4914325dc359518eb Mon Sep 17 00:00:00 2001 From: Alasdair Kergon Date: Mon, 26 Jan 2009 22:13:22 +0000 Subject: [PATCH] Introduce as-yet-unused _vg_lock_and_read() and associated header file definitions. --- lib/metadata/metadata-exported.h | 34 +++++++ lib/metadata/metadata.c | 163 +++++++++++++++++++++++++++++++ 2 files changed, 197 insertions(+) diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h index a05212f41..6f9da08e2 100644 --- a/lib/metadata/metadata-exported.h +++ b/lib/metadata/metadata-exported.h @@ -104,6 +104,29 @@ struct pv_segment; #define MIRROR_BY_LV 0x00000002U /* mirror using whole mimage LVs */ #define MIRROR_SKIP_INIT_SYNC 0x00000010U /* skip initial sync */ +/* vg_read and vg_read_for_update flags */ +#define READ_ALLOW_INCONSISTENT 0x00010000U +#define READ_ALLOW_EXPORTED 0x00020000U +#define READ_REQUIRE_RESIZEABLE 0x00040000U +#define READ_CHECK_EXISTENCE 0x00080000U /* Also used in vg->read_status */ + +/* FIXME Deduce these next requirements internally instead of having caller specify. */ +#define LOCK_NONBLOCKING 0x00000100U /* Fail if not available immediately. */ +#define LOCK_KEEP 0x00000200U /* Do not unlock upon read failure. */ + +/* A meta-flag, useful with toollib for_each_* functions. */ +#define READ_FOR_UPDATE 0x00100000U + +/* vg's "read_status" field */ +#define FAILED_INCONSISTENT 0x00000001U +#define FAILED_LOCKING 0x00000002U +#define FAILED_NOTFOUND 0x00000004U +#define FAILED_READ_ONLY 0x00000008U +#define FAILED_EXPORTED 0x00000010U +#define FAILED_RESIZEABLE 0x00000020U +#define FAILED_CLUSTERED 0x00000040U +#define FAILED_ALLOCATION 0x00000080U + /* Ordered list - see lv_manip.c */ typedef enum { ALLOC_INVALID, @@ -232,6 +255,17 @@ struct volume_group { struct dm_list lvs; struct dm_list tags; + + /* + * vg_t handle fields. + * FIXME: Split these out. + */ + + /* + * Store result of the last vg_read(). + * 0 for success else appropriate FAILURE_* bits set. + */ + uint32_t read_status; }; /* There will be one area for each stripe */ diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c index fb8f43103..17ed851d9 100644 --- a/lib/metadata/metadata.c +++ b/lib/metadata/metadata.c @@ -2377,7 +2377,38 @@ int pv_analyze(struct cmd_context *cmd, const char *pv_name, return 1; } +static uint32_t _vg_check_status(const struct volume_group *vg, uint32_t status) +{ + uint32_t failure = 0; + if ((status & CLUSTERED) && + (vg_is_clustered(vg)) && !locking_is_clustered() && + !lockingfailed()) { + log_error("Skipping clustered volume group %s", vg->name); + /* Return because other flags are considered undefined. */ + return FAILED_CLUSTERED; + } + + if ((status & EXPORTED_VG) && + (vg->status & EXPORTED_VG)) { + log_error("Volume group %s is exported", vg->name); + failure |= FAILED_EXPORTED; + } + + if ((status & LVM_WRITE) && + !(vg->status & LVM_WRITE)) { + log_error("Volume group %s is read-only", vg->name); + failure |= FAILED_READ_ONLY; + } + + if ((status & RESIZEABLE_VG) && + !(vg->status & RESIZEABLE_VG)) { + log_error("Volume group %s is not resizeable.", vg->name); + failure |= FAILED_RESIZEABLE; + } + + return failure; +} /** * vg_check_status - check volume group status flags and log error @@ -2461,6 +2492,138 @@ vg_t *vg_lock_and_read(struct cmd_context *cmd, const char *vg_name, return vg; } +/* + * Create a (vg_t) volume group handle from a struct volume_group pointer and a + * possible failure code or zero for success. + */ +static vg_t *_vg_make_handle(struct cmd_context *cmd, + struct volume_group *vg, + uint32_t failure) +{ + if (!vg && !(vg = dm_pool_zalloc(cmd->mem, sizeof(*vg)))) { + log_error("Error allocating vg handle."); + return_NULL; + } + + vg->read_status = failure; + + return (vg_t *)vg; +} + +static vg_t *_recover_vg(struct cmd_context *cmd, const char *lock_name, + const char *vg_name, const char *vgid, + uint32_t lock_flags) +{ + int consistent = 1; + struct volume_group *vg; + + lock_flags &= ~LCK_TYPE_MASK; + lock_flags |= LCK_WRITE; + + unlock_vg(cmd, lock_name); + + dev_close_all(); + + if (!lock_vol(cmd, lock_name, lock_flags)) + return_NULL; + + if (!(vg = vg_read_internal(cmd, vg_name, vgid, &consistent))) + return_NULL; + + if (!consistent) + return_NULL; + + return (vg_t *)vg; +} + +/* + * Consolidated locking, reading, and status flag checking. + * + * If the metadata is inconsistent, setting READ_ALLOW_INCONSISTENT in + * misc_flags will return it with FAILED_INCONSISTENT set instead of + * giving you nothing. + * + * Use vg_read_error(vg) to determine the result. Nonzero means there were + * problems reading the volume group. + * Zero value means that the VG is open and appropriate locks are held. + */ +static vg_t *_vg_lock_and_read(struct cmd_context *cmd, const char *vg_name, + const char *vgid, uint32_t lock_flags, + uint32_t status_flags, uint32_t misc_flags) +{ + struct volume_group *vg = 0; + const char *lock_name; + int consistent = 1; + int consistent_in; + uint32_t failure = 0; + int already_locked; + + if (misc_flags & READ_ALLOW_INCONSISTENT || !(lock_flags & LCK_WRITE)) + consistent = 0; + + if (!validate_name(vg_name) && !is_orphan_vg(vg_name)) { + log_error("Volume group name %s has invalid characters", + vg_name); + return NULL; + } + + lock_name = is_orphan_vg(vg_name) ? VG_ORPHANS : vg_name; + already_locked = vgname_is_locked(lock_name); + + if (!already_locked && !lock_vol(cmd, lock_name, lock_flags)) { + log_error("Can't get lock for %s", vg_name); + return _vg_make_handle(cmd, vg, FAILED_LOCKING); + } + + if (is_orphan_vg(vg_name)) + status_flags &= ~LVM_WRITE; + + if (misc_flags & READ_CHECK_EXISTENCE) + consistent = 0; + + consistent_in = consistent; + + /* If consistent == 1, we get NULL here if correction fails. */ + if (!(vg = vg_read_internal(cmd, vg_name, vgid, &consistent))) { + if (consistent_in && !consistent) { + log_error("Volume group \"%s\" inconsistent.", vg_name); + failure |= FAILED_INCONSISTENT; + goto_bad; + } + + if (!(misc_flags & READ_CHECK_EXISTENCE)) + log_error("Volume group \"%s\" not found", vg_name); + else + failure |= READ_CHECK_EXISTENCE; + + failure |= FAILED_NOTFOUND; + goto_bad; + } + + /* consistent == 0 when VG is not found, but failed == FAILED_NOTFOUND */ + if (!consistent && !failure) + if (!(vg = _recover_vg(cmd, lock_name, vg_name, vgid, lock_flags))) { + log_error("Recovery of volume group \"%s\" failed.", + vg_name); + failure |= FAILED_INCONSISTENT; + goto_bad; + } + + + failure |= _vg_check_status(vg, status_flags); + if (failure) + goto_bad; + + return _vg_make_handle(cmd, vg, failure); + +bad: + if (failure != (FAILED_NOTFOUND | READ_CHECK_EXISTENCE) && + !(misc_flags & LOCK_KEEP) && !already_locked) + unlock_vg(cmd, lock_name); + + return _vg_make_handle(cmd, vg, failure); +} + /* * Gets/Sets for external LVM library */ -- 2.43.5