- Adds tunable option to fallback to realtime device if configured
when data device is full.
- Useful for realtime device users to help prevent ENOSPC errors when
selectively storing some files (e.g. small files) on data device, while
others are stored on realtime block device.
- Set via the "rt_fallback_pct" sysfs value which is available if
the kernel is compiled with CONFIG_XFS_RT.
Signed-off-by: Richard Wareing <rwareing@xxxxxx>
---
Changes since v3:
* None, new patch to patch set
fs/xfs/xfs_bmap_util.c | 4 +++-
fs/xfs/xfs_fsops.c | 4 ++++
fs/xfs/xfs_iomap.c | 8 ++++++--
fs/xfs/xfs_mount.c | 27 ++++++++++++++++++++++++++-
fs/xfs/xfs_mount.h | 7 ++++++-
fs/xfs/xfs_rtalloc.c | 14 ++++++++++++++
fs/xfs/xfs_rtalloc.h | 3 ++-
fs/xfs/xfs_sysfs.c | 39 +++++++++++++++++++++++++++++++++++++++
8 files changed, 100 insertions(+), 6 deletions(-)
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 2d253fb..9797c69 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1026,8 +1026,10 @@ xfs_alloc_file_space(
if (len <= 0)
return -EINVAL;
- if (XFS_IS_REALTIME_MOUNT(mp))
+ if (XFS_IS_REALTIME_MOUNT(mp)) {
xfs_rt_alloc_min(ip, len);
+ xfs_rt_fallback(ip, mp);
+ }
rt = XFS_IS_REALTIME_INODE(ip);
extsz = xfs_get_extsz_hint(ip);
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 6ccaae9..c15e906 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -610,6 +610,10 @@ xfs_growfs_data_private(
xfs_set_low_space_thresholds(mp);
mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
+ if (XFS_IS_REALTIME_MOUNT(mp)) {
+ xfs_set_rt_min_fdblocks(mp);
+ }
+
/*
* If we expanded the last AG, free the per-AG reservation
* so we can reinitialize it with the new size.
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 11f1c95..707ba97 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -176,8 +176,10 @@ xfs_iomap_write_direct(
uint tflags = 0;
- if (XFS_IS_REALTIME_MOUNT(mp))
+ if (XFS_IS_REALTIME_MOUNT(mp)) {
xfs_rt_alloc_min(ip, count);
+ xfs_rt_fallback(ip, mp);
+ }
rt = XFS_IS_REALTIME_INODE(ip);
extsz = xfs_get_extsz_hint(ip);
@@ -986,8 +988,10 @@ xfs_file_iomap_begin(
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
- if (XFS_IS_REALTIME_MOUNT(mp))
+ if (XFS_IS_REALTIME_MOUNT(mp)) {
xfs_rt_alloc_min(ip, length);
+ xfs_rt_fallback(ip, mp);
+ }
if (((flags & (IOMAP_WRITE | IOMAP_DIRECT)) == IOMAP_WRITE) &&
!IS_DAX(inode) && !xfs_get_extsz_hint(ip)) {
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 2eaf818..543e80d 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -509,7 +509,6 @@ xfs_set_low_space_thresholds(
}
}
-
/*
* Set whether we're using inode alignment.
*/
@@ -1396,3 +1395,29 @@ xfs_dev_is_read_only(
}
return 0;
}
+
+/*
+ * precalculate minimum of data blocks required, if we fall
+ * below this value, we will fallback to the real-time device.
+ *
+ * m_rt_fallback_pct can only be non-zero if a real-time device
+ * is configured.
+ */
+void
+xfs_set_rt_min_fdblocks(
+ struct xfs_mount *mp)
+{
+ if (mp->m_rt_fallback_pct) {
+ xfs_sb_t *sbp = &mp->m_sb;
+ xfs_extlen_t lsize;
+ __uint64_t min_blocks;
+
+ lsize = sbp->sb_logstart ? sbp->sb_logblocks : 0;
+ min_blocks = (mp->m_sb.sb_dblocks - lsize) * mp->m_rt_fallback_pct;
+ do_div(min_blocks, 100);
+ /* Pre-compute minimum data blocks required before
+ * falling back to RT device for allocations
+ */
+ mp->m_rt_min_fdblocks = min_blocks;
+ }
+}
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 067be3b..36676c4 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -197,7 +197,11 @@ typedef struct xfs_mount {
__uint32_t m_generation;
bool m_fail_unmount;
- uint m_rt_alloc_min; /* Min RT allocation */
+ uint m_rt_alloc_min; /* Min RT allocation */
+ __uint8_t m_rt_fallback_pct; /* Fall back to realtime device if
+ * data dev above rt_fallback_pct
+ */
+ __uint64_t m_rt_min_fdblocks; /* Realtime min fdblock threshold */
#ifdef DEBUG
/*
* DEBUG mode instrumentation to test and/or trigger delayed allocation
@@ -463,4 +467,5 @@ int xfs_zero_extent(struct xfs_inode *ip, xfs_fsblock_t start_fsb,
struct xfs_error_cfg * xfs_error_get_cfg(struct xfs_mount *mp,
int error_class, int error);
+void xfs_set_rt_min_fdblocks(struct xfs_mount *mp);
#endif /* __XFS_MOUNT_H__ */
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index e51cb25..f0d25a0 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -1310,3 +1310,17 @@ void xfs_rt_alloc_min(
}
}
}
+
+void xfs_rt_fallback(
+ struct xfs_inode *ip,
+ struct xfs_mount *mp)
+{
+ if (!XFS_IS_REALTIME_INODE(ip)) {
+ __uint64_t free;
+ free = percpu_counter_sum(&mp->m_fdblocks) -
+ mp->m_alloc_set_aside;
+ if (free < mp->m_rt_min_fdblocks) {
+ ip->i_d.di_flags |= XFS_DIFLAG_REALTIME;
+ }
+ }
+}
diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index 12939d9..28f3e42 100644
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -137,7 +137,7 @@ int xfs_rtalloc_query_all(struct xfs_trans *tp,
xfs_rtalloc_query_range_fn fn,
void *priv);
void xfs_rt_alloc_min(struct xfs_inode *ip, xfs_off_t len);
-
+void xfs_rt_fallback(struct xfs_inode *ip, struct xfs_mount *mp);
#else
# define xfs_rtallocate_extent(t,b,min,max,l,f,p,rb) (ENOSYS)
@@ -159,6 +159,7 @@ xfs_rtmount_init(
# define xfs_rtmount_inodes(m) (((mp)->m_sb.sb_rblocks == 0)? 0 : (ENOSYS))
# define xfs_rtunmount_inodes(m)
# define xfs_rt_alloc_min(i,l) (ENOSYS)
+# define xfs_rt_fallback(i,m) (ENOSYS)
#endif /* CONFIG_XFS_RT */
#endif /* __XFS_RTALLOC_H__ */
diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c
index 3c8dedb..c22da05 100644
--- a/fs/xfs/xfs_sysfs.c
+++ b/fs/xfs/xfs_sysfs.c
@@ -165,6 +165,44 @@ rt_alloc_min_show(
return snprintf(buf, PAGE_SIZE, "%d\n", mp->m_rt_alloc_min);
}
XFS_SYSFS_ATTR_RW(rt_alloc_min);
+
+STATIC ssize_t
+rt_fallback_pct_store(
+ struct kobject *kobject,
+ const char *buf,
+ size_t count)
+{
+ struct xfs_mount *mp = to_mp(kobject);
+ int ret;
+ int val;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ /* Only valid if using a real-time device */
+ if (XFS_IS_REALTIME_MOUNT(mp) && ((val > 0) && (val <=100))) {
+ mp->m_rt_fallback_pct = val;
+ xfs_set_rt_min_fdblocks(mp);
+ } else if (val <= 0) {
+ mp->m_rt_fallback_pct = 0;
+ mp->m_rt_min_fdblocks = 0;
+ } else
+ return -EINVAL;
+
+ return count;
+}
+
+STATIC ssize_t
+rt_fallback_pct_show(
+ struct kobject *kobject,
+ char *buf)
+{
+ struct xfs_mount *mp = to_mp(kobject);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", mp->m_rt_fallback_pct);
+}
+XFS_SYSFS_ATTR_RW(rt_fallback_pct);
#endif /* CONFIG_XFS_RT */
static struct attribute *xfs_mp_attrs[] = {
@@ -173,6 +211,7 @@ static struct attribute *xfs_mp_attrs[] = {
#endif
#ifdef CONFIG_XFS_RT
ATTR_LIST(rt_alloc_min),
+ ATTR_LIST(rt_fallback_pct),
#endif
NULL,
};
--
2.9.5
--
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