0af73f61a2
From: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
453 lines
10 KiB
C
453 lines
10 KiB
C
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#include "mdadm.h"
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#include "mdmon.h"
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#include <sys/select.h>
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static char *array_states[] = {
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"clear", "inactive", "suspended", "readonly", "read-auto",
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"clean", "active", "write-pending", "active-idle", NULL };
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static char *sync_actions[] = {
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"idle", "reshape", "resync", "recover", "check", "repair", NULL
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};
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static int write_attr(char *attr, int fd)
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{
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return write(fd, attr, strlen(attr));
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}
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static void add_fd(fd_set *fds, int *maxfd, int fd)
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{
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if (fd < 0)
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return;
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if (fd > *maxfd)
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*maxfd = fd;
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FD_SET(fd, fds);
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}
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static int read_attr(char *buf, int len, int fd)
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{
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int n;
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if (fd < 0) {
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buf[0] = 0;
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return 0;
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}
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lseek(fd, 0, 0);
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n = read(fd, buf, len - 1);
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if (n <= 0) {
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buf[0] = 0;
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return 0;
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}
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buf[n] = 0;
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if (buf[n-1] == '\n')
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buf[n-1] = 0;
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return n;
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}
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static int get_sync_pos(struct active_array *a)
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{
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char buf[30];
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int n;
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n = read_attr(buf, 30, a->sync_pos_fd);
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if (n <= 0)
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return n;
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if (strncmp(buf, "max", 3) == 0) {
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a->sync_pos = ~(unsigned long long)0;
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return 1;
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}
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a->sync_pos = strtoull(buf, NULL, 10);
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return 1;
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}
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static int get_resync_start(struct active_array *a)
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{
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char buf[30];
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int n;
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n = read_attr(buf, 30, a->resync_start_fd);
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if (n <= 0)
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return n;
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a->resync_start = strtoull(buf, NULL, 10);
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return 1;
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}
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static int attr_match(const char *attr, const char *str)
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{
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/* See if attr, read from a sysfs file, matches
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* str. They must either be the same, or attr can
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* have a trailing newline or comma
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*/
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while (*attr && *str && *attr == *str) {
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attr++;
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str++;
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}
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if (*str || (*attr && *attr != ',' && *attr != '\n'))
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return 0;
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return 1;
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}
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static int match_word(const char *word, char **list)
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{
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int n;
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for (n=0; list[n]; n++)
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if (attr_match(word, list[n]))
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break;
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return n;
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}
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static enum array_state read_state(int fd)
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{
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char buf[20];
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int n = read_attr(buf, 20, fd);
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if (n <= 0)
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return bad_word;
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return (enum array_state) match_word(buf, array_states);
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}
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static enum sync_action read_action( int fd)
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{
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char buf[20];
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int n = read_attr(buf, 20, fd);
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if (n <= 0)
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return bad_action;
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return (enum sync_action) match_word(buf, sync_actions);
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}
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int read_dev_state(int fd)
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{
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char buf[60];
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int n = read_attr(buf, 60, fd);
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char *cp;
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int rv = 0;
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if (n <= 0)
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return 0;
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cp = buf;
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while (cp) {
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if (attr_match(cp, "faulty"))
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rv |= DS_FAULTY;
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if (attr_match(cp, "in_sync"))
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rv |= DS_INSYNC;
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if (attr_match(cp, "write_mostly"))
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rv |= DS_WRITE_MOSTLY;
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if (attr_match(cp, "spare"))
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rv |= DS_SPARE;
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if (attr_match(cp, "blocked"))
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rv |= DS_BLOCKED;
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cp = strchr(cp, ',');
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if (cp)
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cp++;
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}
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return rv;
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}
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/* Monitor a set of active md arrays - all of which share the
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* same metadata - and respond to events that require
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* metadata update.
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*
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* New arrays are detected by another thread which allocates
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* required memory and attaches the data structure to our list.
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*
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* Events:
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* Array stops.
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* This is detected by array_state going to 'clear' or 'inactive'.
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* while we thought it was active.
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* Response is to mark metadata as clean and 'clear' the array(??)
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* write-pending
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* array_state if 'write-pending'
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* We mark metadata as 'dirty' then set array to 'active'.
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* active_idle
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* Either ignore, or mark clean, then mark metadata as clean.
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*
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* device fails
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* detected by rd-N/state reporting "faulty"
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* mark device as 'failed' in metadata, let the kernel release the
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* device by writing '-blocked' to rd/state, and finally write 'remove' to
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* rd/state. Before a disk can be replaced it must be failed and removed
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* from all container members, this will be preemptive for the other
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* arrays... safe?
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*
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* sync completes
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* sync_action was 'resync' and becomes 'idle' and resync_start becomes
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* MaxSector
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* Notify metadata that sync is complete.
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* "Deal with Degraded"
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*
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* recovery completes
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* sync_action changes from 'recover' to 'idle'
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* Check each device state and mark metadata if 'faulty' or 'in_sync'.
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* "Deal with Degraded"
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*
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* deal with degraded array
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* We only do this when first noticing the array is degraded.
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* This can be when we first see the array, when sync completes or
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* when recovery completes.
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*
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* Check if number of failed devices suggests recovery is needed, and
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* skip if not.
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* Ask metadata for a spare device
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* Add device as not in_sync and give a role
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* Update metadata.
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* Start recovery.
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*
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* deal with resync
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* This only happens on finding a new array... mdadm will have set
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* 'resync_start' to the correct value. If 'resync_start' indicates that an
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* resync needs to occur set the array to the 'active' state rather than the
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* initial read-auto state.
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*
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*
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*
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* We wait for a change (poll/select) on array_state, sync_action, and
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* each rd-X/state file.
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* When we get any change, we check everything. So read each state file,
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* then decide what to do.
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*
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* The core action is to write new metadata to all devices in the array.
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* This is done at most once on any wakeup.
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* After that we might:
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* - update the array_state
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* - set the role of some devices.
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* - request a sync_action
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*
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*/
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static int read_and_act(struct active_array *a)
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{
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int check_degraded;
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int deactivate = 0;
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struct mdinfo *mdi;
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a->next_state = bad_word;
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a->next_action = bad_action;
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a->curr_state = read_state(a->info.state_fd);
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a->curr_action = read_action(a->action_fd);
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for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
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mdi->next_state = 0;
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if (mdi->state_fd > 0)
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mdi->curr_state = read_dev_state(mdi->state_fd);
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}
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if (a->curr_state <= inactive &&
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a->prev_state > inactive) {
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/* array has been stopped */
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get_sync_pos(a);
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a->container->ss->mark_clean(a, a->sync_pos);
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a->next_state = clear;
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deactivate = 1;
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}
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if (a->curr_state == write_pending) {
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a->container->ss->mark_dirty(a);
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a->next_state = active;
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}
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if (a->curr_state == active_idle) {
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/* Set array to 'clean' FIRST, then
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* a->ss->mark_clean(a);
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* just ignore for now.
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*/
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}
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if (a->curr_state == readonly) {
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/* Well, I'm ready to handle things, so
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* read-auto is OK. FIXME what if we really want
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* readonly ???
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*/
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get_resync_start(a);
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if (a->resync_start == ~0ULL)
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a->next_state = read_auto; /* array is clean */
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else {
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a->container->ss->mark_dirty(a);
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a->next_state = active;
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}
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}
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if (a->curr_action == idle &&
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a->prev_action == resync) {
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/* check resync_start to see if it is 'max' */
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get_resync_start(a);
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a->container->ss->mark_sync(a, a->resync_start);
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check_degraded = 1;
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}
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if (a->curr_action == idle &&
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a->prev_action == recover) {
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for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
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a->container->ss->set_disk(a, mdi->disk.raid_disk,
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mdi->curr_state);
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if (! (mdi->curr_state & DS_INSYNC))
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check_degraded = 1;
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}
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}
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for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
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if (mdi->curr_state & DS_FAULTY) {
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a->container->ss->set_disk(a, mdi->disk.raid_disk,
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mdi->curr_state);
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check_degraded = 1;
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mdi->next_state = DS_REMOVE;
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}
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}
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if (check_degraded) {
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// FIXME;
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}
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a->container->ss->sync_metadata(a);
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/* Effect state changes in the array */
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if (a->next_state != bad_word)
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write_attr(array_states[a->next_state], a->info.state_fd);
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if (a->next_action != bad_action)
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write_attr(sync_actions[a->next_action], a->action_fd);
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for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
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if (mdi->next_state == DS_REMOVE && mdi->state_fd > 0) {
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int remove_err;
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write_attr("-blocked", mdi->state_fd);
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/* the kernel may not be able to immediately remove the
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* disk, we can simply wait until the next event to try
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* again.
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*/
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remove_err = write_attr("remove", mdi->state_fd);
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if (!remove_err) {
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close(mdi->state_fd);
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mdi->state_fd = -1;
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}
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}
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if (mdi->next_state & DS_INSYNC)
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write_attr("+in_sync", mdi->state_fd);
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}
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/* move curr_ to prev_ */
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a->prev_state = a->curr_state;
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a->prev_action = a->curr_action;
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for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
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mdi->prev_state = mdi->curr_state;
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mdi->next_state = 0;
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}
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if (deactivate)
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a->container = NULL;
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return 1;
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}
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static struct mdinfo *
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find_device(struct active_array *a, int major, int minor)
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{
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struct mdinfo *mdi;
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for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
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if (mdi->disk.major == major && mdi->disk.minor == minor)
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return mdi;
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return NULL;
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}
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static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
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{
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struct active_array *a;
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struct mdinfo *victim;
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for (a = aa; a; a = a->next) {
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if (!a->container)
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continue;
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victim = find_device(a, failed->disk.major, failed->disk.minor);
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if (!victim)
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continue;
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if (!(victim->curr_state & DS_FAULTY))
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write_attr("faulty", victim->state_fd);
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}
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}
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static int wait_and_act(struct active_array *aa, int pfd, int nowait)
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{
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fd_set rfds;
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int maxfd = 0;
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struct active_array *a;
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int rv;
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struct mdinfo *mdi;
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FD_ZERO(&rfds);
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add_fd(&rfds, &maxfd, pfd);
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for (a = aa ; a ; a = a->next) {
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/* once an array has been deactivated only the manager
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* thread can make us care about it again
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*/
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if (!a->container)
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continue;
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add_fd(&rfds, &maxfd, a->info.state_fd);
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add_fd(&rfds, &maxfd, a->action_fd);
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for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
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add_fd(&rfds, &maxfd, mdi->state_fd);
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}
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if (!nowait) {
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rv = select(maxfd+1, &rfds, NULL, NULL, NULL);
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if (rv <= 0)
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return rv;
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if (FD_ISSET(pfd, &rfds)) {
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char buf[4];
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read(pfd, buf, 4);
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; // FIXME read from the pipe
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}
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}
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for (a = aa; a ; a = a->next) {
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if (a->replaces && !discard_this) {
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struct active_array **ap;
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for (ap = &a->next; *ap && *ap != a->replaces;
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ap = & (*ap)->next)
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;
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if (*ap)
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*ap = (*ap)->next;
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discard_this = a->replaces;
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a->replaces = NULL;
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}
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if (a->container)
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rv += read_and_act(a);
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}
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/* propagate failures across container members */
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for (a = aa; a ; a = a->next) {
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if (!a->container)
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continue;
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for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
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if (mdi->curr_state & DS_FAULTY)
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reconcile_failed(aa, mdi);
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}
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return rv;
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}
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void do_monitor(struct supertype *container)
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{
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int rv;
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int first = 1;
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do {
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rv = wait_and_act(container->arrays, container->pipe[0], first);
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first = 0;
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} while (rv >= 0);
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}
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