[Devel] [PATCH RHEL8 COMMIT] ploop: Stop using kvec
Konstantin Khorenko
khorenko at virtuozzo.com
Fri Jul 2 22:51:54 MSK 2021
The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.51
------>
commit 59e151b419fda50aec6c6a956a54060f16f0d2b7
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date: Fri Jul 2 22:51:54 2021 +0300
ploop: Stop using kvec
Our files are open with O_DIRECT. In this case,
kvec is not possible, since iov_iter_get_pages()
can't work with it. So, every read results
in EFAULT.
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
==========================
ploop: Stop using kvec
We can't read using kvec from file open with O_DIRECT.
This makes ploop to stop use it.
Kirill Tkhai (8):
ploop: Read metadata page-aligned
ploop: RAW image does not have header
ploop: Introduce ploop_init_be_iter()
ploop: Introduce rb_root_for_each_md_page()
ploop: Introduce md helpers
ploop: Stop using kvec
ploop: Kill dead check
ploop: Shorten delta_bat_entries
---
drivers/md/dm-ploop-bat.c | 130 +++++++++++++++++++++++++++++-----------------
drivers/md/dm-ploop-cmd.c | 28 +++++-----
drivers/md/dm-ploop.h | 3 +-
3 files changed, 97 insertions(+), 64 deletions(-)
diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index a3abf1f509ef..036edc317de3 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -313,12 +313,18 @@ int ploop_setup_metadata(struct ploop *ploop, struct page *page)
}
static int ploop_delta_check_header(struct ploop *ploop,
- struct ploop_pvd_header *d_hdr,
+ struct rb_root *md_root,
u32 *delta_nr_be_ret)
{
u32 bytes, delta_nr_be, offset_clusters, bat_clusters;
+ struct rb_node *node = rb_first(md_root);
+ struct md_page *md0 = rb_entry(node, struct md_page, node);
+ struct ploop_pvd_header *d_hdr;
int ret = -EPROTO;
+ WARN_ON_ONCE(md0->id != 0);
+
+ d_hdr = kmap(md0->page);
if (memcmp(d_hdr->m_Sig, ploop->m_Sig, sizeof(d_hdr->m_Sig)) ||
d_hdr->m_Sectors != ploop->m_Sectors ||
d_hdr->m_Type != ploop->m_Type)
@@ -336,72 +342,96 @@ static int ploop_delta_check_header(struct ploop *ploop,
*delta_nr_be_ret = delta_nr_be;
ret = 0;
out:
+ kunmap(md0->page);
return ret;
}
-int convert_bat_entries(struct ploop *ploop, u32 *bat_entries, u32 nr_be)
+static int convert_bat_entries(struct ploop *ploop, struct rb_root *md_root, u32 nr_be)
{
- u32 i, bytes, bat_clusters;
+ u32 i, end, bytes, bat_clusters, *bat_entries;
+ struct rb_node *node;
+ struct md_page *md;
+ int ret = 0;
bytes = (PLOOP_MAP_OFFSET + nr_be) * sizeof(map_index_t);
bat_clusters = DIV_ROUND_UP(bytes, CLU_SIZE(ploop));
- for (i = 0; i < nr_be; i++) {
- if (bat_entries[i] == BAT_ENTRY_NONE)
- return -EPROTO;
- if (!bat_entries[i])
- bat_entries[i] = BAT_ENTRY_NONE;
- if (bat_entries[i] < bat_clusters)
- return -EXDEV;
+ rb_root_for_each_md_page(md_root, md, node) {
+ bat_entries = kmap(md->page);
+ init_be_iter(nr_be, md->id, &i, &end);
+
+ for (; i <= end; i++) {
+ if (bat_entries[i] == BAT_ENTRY_NONE)
+ ret = -EPROTO;
+ if (!bat_entries[i])
+ bat_entries[i] = BAT_ENTRY_NONE;
+ if (bat_entries[i] < bat_clusters)
+ ret = -EXDEV;
+ }
+ kunmap(md->page);
+
+ if (ret)
+ break;
}
- return 0;
+ return ret;
}
int ploop_read_delta_metadata(struct ploop *ploop, struct file *file,
- void **d_hdr, u32 *delta_nr_be_ret)
+ struct rb_root *md_root, u32 *delta_nr_be_ret)
{
- u32 size, delta_nr_be, *delta_bat_entries;
+ u32 i, size, delta_nr_be, nr_segs;
+ struct bio_vec *bvec = NULL;
struct iov_iter iter;
- struct kvec kvec;
+ struct rb_node *node;
+ struct md_page *md;
ssize_t len;
loff_t pos;
int ret;
+ ret = -ENOMEM;
+ if (prealloc_md_pages(md_root, 0, ploop->nr_bat_entries))
+ goto out;
+
size = (PLOOP_MAP_OFFSET + ploop->nr_bat_entries) * sizeof(map_index_t);
size = ALIGN(size, PAGE_SIZE); /* file may be open as direct */
- *d_hdr = vzalloc(size);
- if (!*d_hdr) {
- ret = -ENOMEM;
+ nr_segs = size / PAGE_SIZE;
+
+ bvec = kvmalloc(sizeof(*bvec) * nr_segs, GFP_KERNEL);
+ if (!bvec)
goto out;
- }
- kvec.iov_base = *d_hdr;
- kvec.iov_len = size;
+ ret = -EMLINK;
+ i = 0;
+ rb_root_for_each_md_page(md_root, md, node) {
+ if (WARN_ON_ONCE(md->id != i))
+ goto out;
+ bvec[i].bv_page = md->page;
+ bvec[i].bv_len = PAGE_SIZE;
+ bvec[i].bv_offset = 0;
+ i++;
+ }
- iov_iter_kvec(&iter, READ, &kvec, 1, kvec.iov_len);
+ iov_iter_bvec(&iter, READ, bvec, nr_segs, size);
pos = 0;
len = vfs_iter_read(file, &iter, &pos, 0);
if (len != size) {
ret = len < 0 ? (int)len : -ENODATA;
- goto out_vfree;
+ goto out;
}
- ret = ploop_delta_check_header(ploop, *d_hdr, &delta_nr_be);
+ ret = ploop_delta_check_header(ploop, md_root, &delta_nr_be);
if (ret)
- goto out_vfree;
+ goto out;
- delta_bat_entries = *d_hdr + PLOOP_MAP_OFFSET * sizeof(map_index_t);
- ret = convert_bat_entries(ploop, delta_bat_entries, delta_nr_be);
+ ret = convert_bat_entries(ploop, md_root, delta_nr_be);
*delta_nr_be_ret = delta_nr_be;
-out_vfree:
- if (ret) {
- vfree(*d_hdr);
- *d_hdr = NULL;
- }
out:
+ if (ret)
+ free_md_pages_tree(md_root);
+ kvfree(bvec);
return ret;
}
@@ -420,37 +450,38 @@ static void ploop_set_not_hole(struct ploop *ploop, u32 dst_clu)
* n)add oldest delta
*/
static void apply_delta_mappings(struct ploop *ploop, struct ploop_delta *deltas,
- u32 level, void *hdr, u64 size_in_clus)
+ u32 level, struct rb_root *md_root, u64 size_in_clus)
{
- map_index_t *bat_entries, *delta_bat_entries;
+ map_index_t *bat_entries, *delta_bat_entries = NULL;
bool is_top_level, is_raw, stop = false;
+ struct md_page *md, *d_md = NULL;
u32 i, end, dst_clu, clu;
struct rb_node *node;
- struct md_page *md;
- /* Points to hdr since md_page[0] also contains hdr. */
- delta_bat_entries = (map_index_t *)hdr;
is_raw = deltas[level].is_raw;
is_top_level = (level == top_level(ploop));
+ if (!is_raw)
+ d_md = md_first_entry(md_root);
+
write_lock_irq(&ploop->bat_rwlock);
ploop_for_each_md_page(ploop, md, node) {
bat_entries = kmap_atomic(md->page);
+ if (!is_raw)
+ delta_bat_entries = kmap_atomic(d_md->page);
if (is_top_level && md->id == 0 && !is_raw) {
/* bat_entries before PLOOP_MAP_OFFSET is hdr */
- memcpy(bat_entries, hdr, sizeof(struct ploop_pvd_header));
+ memcpy(bat_entries, delta_bat_entries,
+ sizeof(struct ploop_pvd_header));
}
- ploop_init_be_iter(ploop, md->id, &i, &end);
+ init_be_iter(size_in_clus, md->id, &i, &end);
for (; i <= end; i++) {
clu = page_clu_idx_to_bat_clu(md->id, i);
- if (clu >= size_in_clus) {
- WARN_ON_ONCE(is_top_level);
+ if (clu == size_in_clus - 1)
stop = true;
- goto unmap;
- }
if (bat_entries[i] != BAT_ENTRY_NONE) {
/* md0 is already populated */
@@ -473,11 +504,14 @@ static void apply_delta_mappings(struct ploop *ploop, struct ploop_delta *deltas
if (is_top_level)
ploop_set_not_hole(ploop, bat_entries[i]);
}
-unmap:
+
kunmap_atomic(bat_entries);
+ if (!is_raw)
+ kunmap_atomic(delta_bat_entries);
if (stop)
break;
- delta_bat_entries += PAGE_SIZE / sizeof(map_index_t);
+ if (!is_raw)
+ d_md = md_next_entry(d_md);
}
write_unlock_irq(&ploop->bat_rwlock);
}
@@ -499,7 +533,7 @@ int ploop_check_delta_length(struct ploop *ploop, struct file *file, loff_t *fil
int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_raw)
{
struct ploop_delta *deltas = ploop->deltas;
- struct ploop_pvd_header *hdr = NULL;
+ struct rb_root md_root = RB_ROOT;
loff_t file_size;
u32 size_in_clus;
int ret;
@@ -509,7 +543,7 @@ int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_r
goto out;
if (!is_raw) {
- ret = ploop_read_delta_metadata(ploop, file, (void *)&hdr,
+ ret = ploop_read_delta_metadata(ploop, file, &md_root,
&size_in_clus);
if (ret)
goto out;
@@ -522,7 +556,7 @@ int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_r
size_in_clus > deltas[level + 1].size_in_clus)
goto out;
- apply_delta_mappings(ploop, deltas, level, (void *)hdr, size_in_clus);
+ apply_delta_mappings(ploop, deltas, level, &md_root, size_in_clus);
deltas[level].file = file;
deltas[level].file_size = file_size;
@@ -531,6 +565,6 @@ int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_r
deltas[level].is_raw = is_raw;
ret = 0;
out:
- vfree(hdr);
+ free_md_pages_tree(&md_root);
return ret;
}
diff --git a/drivers/md/dm-ploop-cmd.c b/drivers/md/dm-ploop-cmd.c
index 9406a1d61000..005fa32aba3a 100644
--- a/drivers/md/dm-ploop-cmd.c
+++ b/drivers/md/dm-ploop-cmd.c
@@ -680,29 +680,28 @@ static int ploop_merge_latest_snapshot(struct ploop *ploop)
return ret;
}
-static void notify_delta_merged(struct ploop *ploop, u8 level, void *hdr,
+static void notify_delta_merged(struct ploop *ploop, u8 level,
+ struct rb_root *md_root,
bool forward, u32 size_in_clus)
{
u32 i, end, *bat_entries, *delta_bat_entries;
+ struct md_page *md, *d_md;
struct rb_node *node;
- struct md_page *md;
struct file *file;
bool stop = false;
u32 clu;
- /* Points to hdr since md_page[0] also contains hdr. */
- delta_bat_entries = (map_index_t *)hdr;
+ d_md = md_first_entry(md_root);
write_lock_irq(&ploop->bat_rwlock);
ploop_for_each_md_page(ploop, md, node) {
- ploop_init_be_iter(ploop, md->id, &i, &end);
+ init_be_iter(size_in_clus, md->id, &i, &end);
bat_entries = kmap_atomic(md->page);
+ delta_bat_entries = kmap_atomic(d_md->page);
for (; i <= end; i++) {
clu = page_clu_idx_to_bat_clu(md->id, i);
- if (clu >= size_in_clus) {
+ if (clu == size_in_clus - 1)
stop = true;
- goto unmap;
- }
if (md_page_cluster_is_in_top_delta(ploop, md, i) ||
delta_bat_entries[i] == BAT_ENTRY_NONE ||
@@ -725,11 +724,12 @@ static void notify_delta_merged(struct ploop *ploop, u8 level, void *hdr,
if (!forward)
md->bat_levels[i]--;
}
-unmap:
+
kunmap_atomic(bat_entries);
+ kunmap_atomic(delta_bat_entries);
if (stop)
break;
- delta_bat_entries += PAGE_SIZE / sizeof(map_index_t);
+ d_md = md_next_entry(delta_md);
}
file = ploop->deltas[level].file;
@@ -774,7 +774,7 @@ static int process_update_delta_index(struct ploop *ploop, u8 level,
static int ploop_delta_clusters_merged(struct ploop *ploop, u8 level,
bool forward)
{
- struct ploop_pvd_header *d_hdr = NULL;
+ struct rb_root md_root = RB_ROOT;
struct file *file;
u32 size_in_clus;
int ret;
@@ -782,7 +782,7 @@ static int ploop_delta_clusters_merged(struct ploop *ploop, u8 level,
/* Reread BAT of deltas[@level + 1] (or [@level - 1]) */
file = ploop->deltas[level + forward ? 1 : -1].file;
- ret = ploop_read_delta_metadata(ploop, file, (void *)&d_hdr, &size_in_clus);
+ ret = ploop_read_delta_metadata(ploop, file, &md_root, &size_in_clus);
if (ret)
goto out;
@@ -790,12 +790,12 @@ static int ploop_delta_clusters_merged(struct ploop *ploop, u8 level,
if (ret)
goto out;
- notify_delta_merged(ploop, level, d_hdr, forward, size_in_clus);
+ notify_delta_merged(ploop, level, &md_root, forward, size_in_clus);
ploop_resume_submitting_pios(ploop);
ret = 0;
out:
- vfree(d_hdr);
+ free_md_pages_tree(&md_root);
return ret;
}
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index c26641ce4e2b..9c4b77852c18 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -549,7 +549,6 @@ extern void ploop_free_md_page(struct md_page *md);
extern void free_md_pages_tree(struct rb_root *root);
extern bool try_update_bat_entry(struct ploop *ploop, u32 clu,
u8 level, u32 dst_clu);
-extern int convert_bat_entries(struct ploop *ploop, u32 *bat_entries, u32 count);
extern int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_raw);
extern int ploop_check_delta_length(struct ploop *ploop, struct file *file, loff_t *file_size);
@@ -577,7 +576,7 @@ extern void pio_prepare_offsets(struct ploop *, struct pio *, u32);
extern int ploop_setup_metadata(struct ploop *ploop, struct page *page);
extern int ploop_read_delta_metadata(struct ploop *ploop, struct file *file,
- void **d_hdr, u32 *delta_nr_be);
+ struct rb_root *md_root, u32 *delta_nr_be);
extern void ploop_index_wb_init(struct ploop_index_wb *piwb, struct ploop *ploop);
extern void ploop_call_rw_iter(struct file *file, loff_t pos, unsigned rw,
struct iov_iter *iter, struct pio *pio);
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