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GFP flags adjustments, part 2

PATCH New David Sterba 1 participant 4 messages Jan 19, 2016 Btrfs file system

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David Sterba

author maintainer
#0 lore raw

cover GFP flags adjustments, part 2

Hi,

a few more tweaks to the GFP flags, for 4.5. This is low-risk and still preparatory so we can narrow down the contexts where we can utilize the more fine-grained GFP flags and attack the memory allocation failures.

----------------------------------------------------------------
The following changes since commit 39a27ec1004e886f1d949bdb8f2616896d02c5c2:

btrfs: use GFP_KERNEL for xattr and acl allocations (2015-12-03 15:03:44 +0100)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git dev/gfp-flags

for you to fetch changes up to 3677d94d23ae74d584ba61396aa51e82bb53e2d4:

btrfs: scrub: use GFP_KERNEL on the submission path (2016-01-19 10:17:31 +0100)

----------------------------------------------------------------
David Sterba (3):
btrfs: send: use GFP_KERNEL everywhere
btrfs: reada: use GFP_KERNEL everywhere
btrfs: scrub: use GFP_KERNEL on the submission path

 fs/btrfs/reada.c | 10 +++++-----
 fs/btrfs/scrub.c | 24 +++++++++++++-----------
 fs/btrfs/send.c  | 36 ++++++++++++++++++------------------
 3 files changed, 36 insertions(+), 34 deletions(-)
Signature · 1 line
2.6.3
author maintainer
#1 lore raw

PATCH 1/3 btrfs: send: use GFP_KERNEL everywhere

The send operation is not on the critical writeback path we don't need to use GFP_NOFS for allocations. All error paths are handled and the whole operation is restartable.

Signed-off-by David Sterba <[email protected]>
---
 fs/btrfs/send.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)
fs/btrfs/send.c +18 -18
index 355a458cba1a..1affded5fba0 100644
@@ -304,7 +304,7 @@ static struct fs_path *fs_path_alloc(void)
 {
 	struct fs_path *p;
 
-	p = kmalloc(sizeof(*p), GFP_NOFS);
+	p = kmalloc(sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return NULL;
 	p->reversed = 0;

@@ -363,11 +363,11 @@ static int fs_path_ensure_buf(struct fs_path *p, int len)
 	 * First time the inline_buf does not suffice
 	 */
 	if (p->buf == p->inline_buf) {
-		tmp_buf = kmalloc(len, GFP_NOFS);
+		tmp_buf = kmalloc(len, GFP_KERNEL);
 		if (tmp_buf)
 			memcpy(tmp_buf, p->buf, old_buf_len);
 	} else {
-		tmp_buf = krealloc(p->buf, len, GFP_NOFS);
+		tmp_buf = krealloc(p->buf, len, GFP_KERNEL);
 	}
 	if (!tmp_buf)
 		return -ENOMEM;

@@ -995,7 +995,7 @@ static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
 	 * values are small.
 	 */
 	buf_len = PATH_MAX;
-	buf = kmalloc(buf_len, GFP_NOFS);
+	buf = kmalloc(buf_len, GFP_KERNEL);
 	if (!buf) {
 		ret = -ENOMEM;
 		goto out;

@@ -1042,7 +1042,7 @@ static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
 				buf = NULL;
 			} else {
 				char *tmp = krealloc(buf, buf_len,
-						     GFP_NOFS | __GFP_NOWARN);
+						GFP_KERNEL | __GFP_NOWARN);
 
 				if (!tmp)
 					kfree(buf);

@@ -1303,7 +1303,7 @@ static int find_extent_clone(struct send_ctx *sctx,
 	/* We only use this path under the commit sem */
 	tmp_path->need_commit_sem = 0;
 
-	backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
+	backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_KERNEL);
 	if (!backref_ctx) {
 		ret = -ENOMEM;
 		goto out;

@@ -1970,7 +1970,7 @@ static int name_cache_insert(struct send_ctx *sctx,
 	nce_head = radix_tree_lookup(&sctx->name_cache,
 			(unsigned long)nce->ino);
 	if (!nce_head) {
-		nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
+		nce_head = kmalloc(sizeof(*nce_head), GFP_KERNEL);
 		if (!nce_head) {
 			kfree(nce);
 			return -ENOMEM;

@@ -2165,7 +2165,7 @@ static int __get_cur_name_and_parent(struct send_ctx *sctx,
 	/*
 	 * Store the result of the lookup in the name cache.
 	 */
-	nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
+	nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_KERNEL);
 	if (!nce) {
 		ret = -ENOMEM;
 		goto out;

@@ -2301,7 +2301,7 @@ static int send_subvol_begin(struct send_ctx *sctx)
 	if (!path)
 		return -ENOMEM;
 
-	name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
+	name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL);
 	if (!name) {
 		btrfs_free_path(path);
 		return -ENOMEM;

@@ -2716,7 +2716,7 @@ static int __record_ref(struct list_head *head, u64 dir,
 {
 	struct recorded_ref *ref;
 
-	ref = kmalloc(sizeof(*ref), GFP_NOFS);
+	ref = kmalloc(sizeof(*ref), GFP_KERNEL);
 	if (!ref)
 		return -ENOMEM;
 

@@ -2741,7 +2741,7 @@ static int dup_ref(struct recorded_ref *ref, struct list_head *list)
 {
 	struct recorded_ref *new;
 
-	new = kmalloc(sizeof(*ref), GFP_NOFS);
+	new = kmalloc(sizeof(*ref), GFP_KERNEL);
 	if (!new)
 		return -ENOMEM;
 

@@ -2804,7 +2804,7 @@ add_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
 	struct rb_node *parent = NULL;
 	struct orphan_dir_info *entry, *odi;
 
-	odi = kmalloc(sizeof(*odi), GFP_NOFS);
+	odi = kmalloc(sizeof(*odi), GFP_KERNEL);
 	if (!odi)
 		return ERR_PTR(-ENOMEM);
 	odi->ino = dir_ino;

@@ -2959,7 +2959,7 @@ static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized)
 	struct rb_node *parent = NULL;
 	struct waiting_dir_move *entry, *dm;
 
-	dm = kmalloc(sizeof(*dm), GFP_NOFS);
+	dm = kmalloc(sizeof(*dm), GFP_KERNEL);
 	if (!dm)
 		return -ENOMEM;
 	dm->ino = ino;

@@ -3026,7 +3026,7 @@ static int add_pending_dir_move(struct send_ctx *sctx,
 	int exists = 0;
 	int ret;
 
-	pm = kmalloc(sizeof(*pm), GFP_NOFS);
+	pm = kmalloc(sizeof(*pm), GFP_KERNEL);
 	if (!pm)
 		return -ENOMEM;
 	pm->parent_ino = parent_ino;

@@ -4266,7 +4266,7 @@ static int __find_xattr(int num, struct btrfs_key *di_key,
 	    strncmp(name, ctx->name, name_len) == 0) {
 		ctx->found_idx = num;
 		ctx->found_data_len = data_len;
-		ctx->found_data = kmemdup(data, data_len, GFP_NOFS);
+		ctx->found_data = kmemdup(data, data_len, GFP_KERNEL);
 		if (!ctx->found_data)
 			return -ENOMEM;
 		return 1;

@@ -4467,7 +4467,7 @@ static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
 	while (index <= last_index) {
 		unsigned cur_len = min_t(unsigned, len,
 					 PAGE_CACHE_SIZE - pg_offset);
-		page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+		page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
 		if (!page) {
 			ret = -ENOMEM;
 			break;

@@ -5975,7 +5975,7 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 		goto out;
 	}
 
-	sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
+	sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL);
 	if (!sctx) {
 		ret = -ENOMEM;
 		goto out;

@@ -5983,7 +5983,7 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 
 	INIT_LIST_HEAD(&sctx->new_refs);
 	INIT_LIST_HEAD(&sctx->deleted_refs);
-	INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
+	INIT_RADIX_TREE(&sctx->name_cache, GFP_KERNEL);
 	INIT_LIST_HEAD(&sctx->name_cache_list);
 
 	sctx->flags = arg->flags;
Signature · 1 line
2.6.3
author maintainer
#2 lore raw

PATCH 2/3 btrfs: reada: use GFP_KERNEL everywhere

In reply to David Sterba

The readahead framework is not on the critical writeback path we don't need to use GFP_NOFS for allocations. All error paths are handled and the readahead failures are not fatal. The actual users (scrub, dev-replace) will trigger reads if the blocks are not found in cache.

Signed-off-by David Sterba <[email protected]>
---
 fs/btrfs/reada.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
fs/btrfs/reada.c +5 -5
index 619f92963e27..c5f1773c4794 100644
@@ -280,7 +280,7 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info,
 	end = start + cache->key.offset - 1;
 	btrfs_put_block_group(cache);
 
-	zone = kzalloc(sizeof(*zone), GFP_NOFS);
+	zone = kzalloc(sizeof(*zone), GFP_KERNEL);
 	if (!zone)
 		return NULL;
 

@@ -343,7 +343,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
 	if (re)
 		return re;
 
-	re = kzalloc(sizeof(*re), GFP_NOFS);
+	re = kzalloc(sizeof(*re), GFP_KERNEL);
 	if (!re)
 		return NULL;
 

@@ -566,7 +566,7 @@ static int reada_add_block(struct reada_control *rc, u64 logical,
 	if (!re)
 		return -1;
 
-	rec = kzalloc(sizeof(*rec), GFP_NOFS);
+	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
 	if (!rec) {
 		reada_extent_put(root->fs_info, re);
 		return -ENOMEM;

@@ -791,7 +791,7 @@ static void reada_start_machine(struct btrfs_fs_info *fs_info)
 {
 	struct reada_machine_work *rmw;
 
-	rmw = kzalloc(sizeof(*rmw), GFP_NOFS);
+	rmw = kzalloc(sizeof(*rmw), GFP_KERNEL);
 	if (!rmw) {
 		/* FIXME we cannot handle this properly right now */
 		BUG();

@@ -926,7 +926,7 @@ struct reada_control *btrfs_reada_add(struct btrfs_root *root,
 		.offset = (u64)-1
 	};
 
-	rc = kzalloc(sizeof(*rc), GFP_NOFS);
+	rc = kzalloc(sizeof(*rc), GFP_KERNEL);
 	if (!rc)
 		return ERR_PTR(-ENOMEM);
Signature · 1 line
2.6.3
author maintainer
#3 lore raw

PATCH 3/3 btrfs: scrub: use GFP_KERNEL on the submission path

In reply to David Sterba

Scrub is not on the critical writeback path we don't need to use GFP_NOFS for all allocations. The failures are handled and stats passed back to userspace.

Let's use GFP_KERNEL on the paths where everything is ok, ie. setup the global structures and the IO submission paths.

Functions that do the repair and fixups still use GFP_NOFS as we might want to skip any other filesystem activity if we encounter an error. This could turn out to be unnecessary, but requires more review compared to the easy cases in this patch.

Signed-off-by David Sterba <[email protected]>
---
 fs/btrfs/scrub.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)
fs/btrfs/scrub.c +13 -11
index 2907a77fb1f6..6f722d88d37c 100644
@@ -461,7 +461,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 	struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
 	int ret;
 
-	sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
+	sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
 	if (!sctx)
 		goto nomem;
 	atomic_set(&sctx->refs, 1);

@@ -472,7 +472,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 	for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
 		struct scrub_bio *sbio;
 
-		sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
+		sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
 		if (!sbio)
 			goto nomem;
 		sctx->bios[i] = sbio;

@@ -1656,7 +1656,7 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
 again:
 	if (!wr_ctx->wr_curr_bio) {
 		wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
-					      GFP_NOFS);
+					      GFP_KERNEL);
 		if (!wr_ctx->wr_curr_bio) {
 			mutex_unlock(&wr_ctx->wr_lock);
 			return -ENOMEM;

@@ -1673,7 +1673,8 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
 		sbio->dev = wr_ctx->tgtdev;
 		bio = sbio->bio;
 		if (!bio) {
-			bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
+			bio = btrfs_io_bio_alloc(GFP_KERNEL,
+					wr_ctx->pages_per_wr_bio);
 			if (!bio) {
 				mutex_unlock(&wr_ctx->wr_lock);
 				return -ENOMEM;

@@ -2078,7 +2079,8 @@ static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
 		sbio->dev = spage->dev;
 		bio = sbio->bio;
 		if (!bio) {
-			bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
+			bio = btrfs_io_bio_alloc(GFP_KERNEL,
+					sctx->pages_per_rd_bio);
 			if (!bio)
 				return -ENOMEM;
 			sbio->bio = bio;

@@ -2243,7 +2245,7 @@ static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 	struct scrub_block *sblock;
 	int index;
 
-	sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
+	sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
 	if (!sblock) {
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.malloc_errors++;

@@ -2261,7 +2263,7 @@ static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 		struct scrub_page *spage;
 		u64 l = min_t(u64, len, PAGE_SIZE);
 
-		spage = kzalloc(sizeof(*spage), GFP_NOFS);
+		spage = kzalloc(sizeof(*spage), GFP_KERNEL);
 		if (!spage) {
 leave_nomem:
 			spin_lock(&sctx->stat_lock);

@@ -2288,7 +2290,7 @@ static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 			spage->have_csum = 0;
 		}
 		sblock->page_count++;
-		spage->page = alloc_page(GFP_NOFS);
+		spage->page = alloc_page(GFP_KERNEL);
 		if (!spage->page)
 			goto leave_nomem;
 		len -= l;

@@ -2543,7 +2545,7 @@ static int scrub_pages_for_parity(struct scrub_parity *sparity,
 	struct scrub_block *sblock;
 	int index;
 
-	sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
+	sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
 	if (!sblock) {
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.malloc_errors++;

@@ -2563,7 +2565,7 @@ static int scrub_pages_for_parity(struct scrub_parity *sparity,
 		struct scrub_page *spage;
 		u64 l = min_t(u64, len, PAGE_SIZE);
 
-		spage = kzalloc(sizeof(*spage), GFP_NOFS);
+		spage = kzalloc(sizeof(*spage), GFP_KERNEL);
 		if (!spage) {
 leave_nomem:
 			spin_lock(&sctx->stat_lock);

@@ -2593,7 +2595,7 @@ static int scrub_pages_for_parity(struct scrub_parity *sparity,
 			spage->have_csum = 0;
 		}
 		sblock->page_count++;
-		spage->page = alloc_page(GFP_NOFS);
+		spage->page = alloc_page(GFP_KERNEL);
 		if (!spage->page)
 			goto leave_nomem;
 		len -= l;
Signature · 1 line
2.6.3