diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index d06dd39856f..a3d20265ffc 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -523,8 +523,6 @@ static int list_versions(struct dm_ioctl *param, size_t param_size) return 0; } - - static int check_name(const char *name) { if (strchr(name, '/')) { @@ -535,6 +533,40 @@ static int check_name(const char *name) return 0; } +/* + * On successful return, the caller must not attempt to acquire + * _hash_lock without first calling dm_table_put, because dm_table_destroy + * waits for this dm_table_put and could be called under this lock. + */ +static struct dm_table *dm_get_inactive_table(struct mapped_device *md) +{ + struct hash_cell *hc; + struct dm_table *table = NULL; + + down_read(&_hash_lock); + hc = dm_get_mdptr(md); + if (!hc || hc->md != md) { + DMWARN("device has been removed from the dev hash table."); + goto out; + } + + table = hc->new_map; + if (table) + dm_table_get(table); + +out: + up_read(&_hash_lock); + + return table; +} + +static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md, + struct dm_ioctl *param) +{ + return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ? + dm_get_inactive_table(md) : dm_get_live_table(md); +} + /* * Fills in a dm_ioctl structure, ready for sending back to * userland. @@ -559,18 +591,30 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) */ param->open_count = dm_open_count(md); - if (get_disk_ro(disk)) - param->flags |= DM_READONLY_FLAG; - param->event_nr = dm_get_event_nr(md); + param->target_count = 0; table = dm_get_live_table(md); if (table) { - param->flags |= DM_ACTIVE_PRESENT_FLAG; - param->target_count = dm_table_get_num_targets(table); + if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) { + if (get_disk_ro(disk)) + param->flags |= DM_READONLY_FLAG; + param->target_count = dm_table_get_num_targets(table); + } dm_table_put(table); - } else - param->target_count = 0; + + param->flags |= DM_ACTIVE_PRESENT_FLAG; + } + + if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) { + table = dm_get_inactive_table(md); + if (table) { + if (!(dm_table_get_mode(table) & FMODE_WRITE)) + param->flags |= DM_READONLY_FLAG; + param->target_count = dm_table_get_num_targets(table); + dm_table_put(table); + } + } return 0; } @@ -993,7 +1037,7 @@ static int dev_wait(struct dm_ioctl *param, size_t param_size) if (r) goto out; - table = dm_get_live_table(md); + table = dm_get_live_or_inactive_table(md, param); if (table) { retrieve_status(table, param, param_size); dm_table_put(table); @@ -1226,7 +1270,7 @@ static int table_deps(struct dm_ioctl *param, size_t param_size) if (r) goto out; - table = dm_get_live_table(md); + table = dm_get_live_or_inactive_table(md, param); if (table) { retrieve_deps(table, param, param_size); dm_table_put(table); @@ -1255,13 +1299,13 @@ static int table_status(struct dm_ioctl *param, size_t param_size) if (r) goto out; - table = dm_get_live_table(md); + table = dm_get_live_or_inactive_table(md, param); if (table) { retrieve_status(table, param, param_size); dm_table_put(table); } - out: +out: dm_put(md); return r; } diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h index 2ab84c83c31..aa95508d2f9 100644 --- a/include/linux/dm-ioctl.h +++ b/include/linux/dm-ioctl.h @@ -1,6 +1,6 @@ /* * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited. - * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved. + * Copyright (C) 2004 - 2009 Red Hat, Inc. All rights reserved. * * This file is released under the LGPL. */ @@ -266,9 +266,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 15 +#define DM_VERSION_MINOR 16 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2009-04-01)" +#define DM_VERSION_EXTRA "-ioctl (2009-11-05)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ @@ -309,4 +309,11 @@ enum { */ #define DM_NOFLUSH_FLAG (1 << 11) /* In */ +/* + * If set, any table information returned will relate to the inactive + * table instead of the live one. Always check DM_INACTIVE_PRESENT_FLAG + * is set before using the data returned. + */ +#define DM_QUERY_INACTIVE_TABLE_FLAG (1 << 12) /* In */ + #endif /* _LINUX_DM_IOCTL_H */