From 77169812739dd800bc3620d781a77c50c75165cc Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 14 Sep 2016 07:51:30 +1000 Subject: [PATCH] xfs: normalize "infinite" retries in error configs As it stands today, the "fail immediately" vs. "retry forever" values for max_retries and retry_timeout_seconds in the xfs metadata error configurations are not consistent. A retry_timeout_seconds of 0 means "retry forever," but a max_retries of 0 means "fail immediately." retry_timeout_seconds < 0 is disallowed, while max_retries == -1 means "retry forever." Make this consistent across the error configs, such that a value of 0 means "fail immediately" (i.e. wait 0 seconds, or retry 0 times), and a value of -1 always means "retry forever." This makes retry_timeout a signed long to accommodate the -1, even though it stores jiffies. Given our limit of a 1 day maximum timeout, this should be sufficient even at much higher HZ values than we have available today. Signed-off-by: Eric Sandeen Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_buf_item.c | 5 +++-- fs/xfs/xfs_mount.h | 8 +++++++- fs/xfs/xfs_sysfs.c | 47 ++++++++++++++++++++++++++++++++----------- 3 files changed, 45 insertions(+), 15 deletions(-) diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index 3a279979c39d..2975cb2319f4 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -1095,7 +1095,8 @@ xfs_buf_iodone_callback_error( bp->b_last_error != bp->b_error) { bp->b_flags |= (XBF_WRITE | XBF_DONE | XBF_WRITE_FAIL); bp->b_last_error = bp->b_error; - if (cfg->retry_timeout && !bp->b_first_retry_time) + if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && + !bp->b_first_retry_time) bp->b_first_retry_time = jiffies; xfs_buf_ioerror(bp, 0); @@ -1111,7 +1112,7 @@ xfs_buf_iodone_callback_error( if (cfg->max_retries != XFS_ERR_RETRY_FOREVER && ++bp->b_retries > cfg->max_retries) goto permanent_error; - if (cfg->retry_timeout && + if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && time_after(jiffies, cfg->retry_timeout + bp->b_first_retry_time)) goto permanent_error; diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index b36676cde103..efd4a5526f37 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -57,10 +57,16 @@ enum { #define XFS_ERR_RETRY_FOREVER -1 +/* + * Although retry_timeout is in jiffies which is normally an unsigned long, + * we limit the retry timeout to 86400 seconds, or one day. So even a + * signed 32-bit long is sufficient for a HZ value up to 24855. Making it + * signed lets us store the special "-1" value, meaning retry forever. + */ struct xfs_error_cfg { struct xfs_kobj kobj; int max_retries; - unsigned long retry_timeout; /* in jiffies, 0 = no timeout */ + long retry_timeout; /* in jiffies, -1 = infinite */ }; typedef struct xfs_mount { diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c index 79cfd3fc5324..5f8d55d29a11 100644 --- a/fs/xfs/xfs_sysfs.c +++ b/fs/xfs/xfs_sysfs.c @@ -393,9 +393,15 @@ max_retries_show( struct kobject *kobject, char *buf) { + int retries; struct xfs_error_cfg *cfg = to_error_cfg(kobject); - return snprintf(buf, PAGE_SIZE, "%d\n", cfg->max_retries); + if (cfg->retry_timeout == XFS_ERR_RETRY_FOREVER) + retries = -1; + else + retries = cfg->max_retries; + + return snprintf(buf, PAGE_SIZE, "%d\n", retries); } static ssize_t @@ -415,7 +421,10 @@ max_retries_store( if (val < -1) return -EINVAL; - cfg->max_retries = val; + if (val == -1) + cfg->retry_timeout = XFS_ERR_RETRY_FOREVER; + else + cfg->max_retries = val; return count; } XFS_SYSFS_ATTR_RW(max_retries); @@ -425,10 +434,15 @@ retry_timeout_seconds_show( struct kobject *kobject, char *buf) { + int timeout; struct xfs_error_cfg *cfg = to_error_cfg(kobject); - return snprintf(buf, PAGE_SIZE, "%ld\n", - jiffies_to_msecs(cfg->retry_timeout) / MSEC_PER_SEC); + if (cfg->retry_timeout == XFS_ERR_RETRY_FOREVER) + timeout = -1; + else + timeout = jiffies_to_msecs(cfg->retry_timeout) / MSEC_PER_SEC; + + return snprintf(buf, PAGE_SIZE, "%d\n", timeout); } static ssize_t @@ -445,11 +459,16 @@ retry_timeout_seconds_store( if (ret) return ret; - /* 1 day timeout maximum */ - if (val < 0 || val > 86400) + /* 1 day timeout maximum, -1 means infinite */ + if (val < -1 || val > 86400) return -EINVAL; - cfg->retry_timeout = msecs_to_jiffies(val * MSEC_PER_SEC); + if (val == -1) + cfg->retry_timeout = XFS_ERR_RETRY_FOREVER; + else { + cfg->retry_timeout = msecs_to_jiffies(val * MSEC_PER_SEC); + ASSERT(msecs_to_jiffies(val * MSEC_PER_SEC) < LONG_MAX); + } return count; } XFS_SYSFS_ATTR_RW(retry_timeout_seconds); @@ -519,18 +538,19 @@ struct xfs_error_init { static const struct xfs_error_init xfs_error_meta_init[XFS_ERR_ERRNO_MAX] = { { .name = "default", .max_retries = XFS_ERR_RETRY_FOREVER, - .retry_timeout = 0, + .retry_timeout = XFS_ERR_RETRY_FOREVER, }, { .name = "EIO", .max_retries = XFS_ERR_RETRY_FOREVER, - .retry_timeout = 0, + .retry_timeout = XFS_ERR_RETRY_FOREVER, }, { .name = "ENOSPC", .max_retries = XFS_ERR_RETRY_FOREVER, - .retry_timeout = 0, + .retry_timeout = XFS_ERR_RETRY_FOREVER, }, { .name = "ENODEV", - .max_retries = 0, + .max_retries = 0, /* We can't recover from devices disappearing */ + .retry_timeout = 0, }, }; @@ -561,7 +581,10 @@ xfs_error_sysfs_init_class( goto out_error; cfg->max_retries = init[i].max_retries; - cfg->retry_timeout = msecs_to_jiffies( + if (init[i].retry_timeout == XFS_ERR_RETRY_FOREVER) + cfg->retry_timeout = XFS_ERR_RETRY_FOREVER; + else + cfg->retry_timeout = msecs_to_jiffies( init[i].retry_timeout * MSEC_PER_SEC); } return 0;