summary refs log tree commit diff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--Documentation/filesystems/erofs.rst3
-rw-r--r--fs/erofs/data.c42
-rw-r--r--fs/erofs/inode.c4
-rw-r--r--fs/erofs/internal.h3
-rw-r--r--fs/erofs/super.c59
5 files changed, 107 insertions, 4 deletions
diff --git a/Documentation/filesystems/erofs.rst b/Documentation/filesystems/erofs.rst
index 832839fcf4c3..868e3972227f 100644
--- a/Documentation/filesystems/erofs.rst
+++ b/Documentation/filesystems/erofs.rst
@@ -84,6 +84,9 @@ cache_strategy=%s      Select a strategy for cached decompression from now on:
                                    It still does in-place I/O decompression
                                    for the rest compressed physical clusters.
 		       ==========  =============================================
+dax={always,never}     Use direct access (no page cache).  See
+                       Documentation/filesystems/dax.rst.
+dax                    A legacy option which is an alias for ``dax=always``.
 ===================    =========================================================
 
 On-disk details
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 4158572c9e1e..fb2e554c861b 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -6,7 +6,7 @@
 #include "internal.h"
 #include <linux/prefetch.h>
 #include <linux/iomap.h>
-
+#include <linux/dax.h>
 #include <trace/events/erofs.h>
 
 static void erofs_readendio(struct bio *bio)
@@ -323,6 +323,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		return ret;
 
 	iomap->bdev = inode->i_sb->s_bdev;
+	iomap->dax_dev = EROFS_I_SB(inode)->dax_dev;
 	iomap->offset = map.m_la;
 	iomap->length = map.m_llen;
 	iomap->flags = 0;
@@ -382,6 +383,10 @@ static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	if (!iov_iter_count(to))
 		return 0;
 
+#ifdef CONFIG_FS_DAX
+	if (IS_DAX(iocb->ki_filp->f_mapping->host))
+		return dax_iomap_rw(iocb, to, &erofs_iomap_ops);
+#endif
 	if (iocb->ki_flags & IOCB_DIRECT) {
 		int err = erofs_prepare_dio(iocb, to);
 
@@ -402,9 +407,42 @@ const struct address_space_operations erofs_raw_access_aops = {
 	.direct_IO = noop_direct_IO,
 };
 
+#ifdef CONFIG_FS_DAX
+static vm_fault_t erofs_dax_huge_fault(struct vm_fault *vmf,
+		enum page_entry_size pe_size)
+{
+	return dax_iomap_fault(vmf, pe_size, NULL, NULL, &erofs_iomap_ops);
+}
+
+static vm_fault_t erofs_dax_fault(struct vm_fault *vmf)
+{
+	return erofs_dax_huge_fault(vmf, PE_SIZE_PTE);
+}
+
+static const struct vm_operations_struct erofs_dax_vm_ops = {
+	.fault		= erofs_dax_fault,
+	.huge_fault	= erofs_dax_huge_fault,
+};
+
+static int erofs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	if (!IS_DAX(file_inode(file)))
+		return generic_file_readonly_mmap(file, vma);
+
+	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
+		return -EINVAL;
+
+	vma->vm_ops = &erofs_dax_vm_ops;
+	vma->vm_flags |= VM_HUGEPAGE;
+	return 0;
+}
+#else
+#define erofs_file_mmap	generic_file_readonly_mmap
+#endif
+
 const struct file_operations erofs_file_fops = {
 	.llseek		= generic_file_llseek,
 	.read_iter	= erofs_file_read_iter,
-	.mmap		= generic_file_readonly_mmap,
+	.mmap		= erofs_file_mmap,
 	.splice_read	= generic_file_splice_read,
 };
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index f296e1a2661e..92728da1d206 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -174,6 +174,10 @@ static struct page *erofs_read_inode(struct inode *inode,
 	inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
 	inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
 
+	inode->i_flags &= ~S_DAX;
+	if (test_opt(&sbi->ctx, DAX_ALWAYS) && S_ISREG(inode->i_mode) &&
+	    vi->datalayout == EROFS_INODE_FLAT_PLAIN)
+		inode->i_flags |= S_DAX;
 	if (!nblks)
 		/* measure inode.i_blocks as generic filesystems */
 		inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 2669c785d548..7c9abfc93109 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -83,6 +83,7 @@ struct erofs_sb_info {
 
 	struct erofs_sb_lz4_info lz4;
 #endif	/* CONFIG_EROFS_FS_ZIP */
+	struct dax_device *dax_dev;
 	u32 blocks;
 	u32 meta_blkaddr;
 #ifdef CONFIG_EROFS_FS_XATTR
@@ -115,6 +116,8 @@ struct erofs_sb_info {
 /* Mount flags set via mount options or defaults */
 #define EROFS_MOUNT_XATTR_USER		0x00000010
 #define EROFS_MOUNT_POSIX_ACL		0x00000020
+#define EROFS_MOUNT_DAX_ALWAYS		0x00000040
+#define EROFS_MOUNT_DAX_NEVER		0x00000080
 
 #define clear_opt(ctx, option)	((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
 #define set_opt(ctx, option)	((ctx)->mount_opt |= EROFS_MOUNT_##option)
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 8fc6c04b54f4..e8de689c94f4 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -11,6 +11,7 @@
 #include <linux/crc32c.h>
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
+#include <linux/dax.h>
 #include "xattr.h"
 
 #define CREATE_TRACE_POINTS
@@ -355,6 +356,8 @@ enum {
 	Opt_user_xattr,
 	Opt_acl,
 	Opt_cache_strategy,
+	Opt_dax,
+	Opt_dax_enum,
 	Opt_err
 };
 
@@ -365,14 +368,47 @@ static const struct constant_table erofs_param_cache_strategy[] = {
 	{}
 };
 
+static const struct constant_table erofs_dax_param_enums[] = {
+	{"always",	EROFS_MOUNT_DAX_ALWAYS},
+	{"never",	EROFS_MOUNT_DAX_NEVER},
+	{}
+};
+
 static const struct fs_parameter_spec erofs_fs_parameters[] = {
 	fsparam_flag_no("user_xattr",	Opt_user_xattr),
 	fsparam_flag_no("acl",		Opt_acl),
 	fsparam_enum("cache_strategy",	Opt_cache_strategy,
 		     erofs_param_cache_strategy),
+	fsparam_flag("dax",             Opt_dax),
+	fsparam_enum("dax",		Opt_dax_enum, erofs_dax_param_enums),
 	{}
 };
 
+static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode)
+{
+#ifdef CONFIG_FS_DAX
+	struct erofs_fs_context *ctx = fc->fs_private;
+
+	switch (mode) {
+	case EROFS_MOUNT_DAX_ALWAYS:
+		warnfc(fc, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
+		set_opt(ctx, DAX_ALWAYS);
+		clear_opt(ctx, DAX_NEVER);
+		return true;
+	case EROFS_MOUNT_DAX_NEVER:
+		set_opt(ctx, DAX_NEVER);
+		clear_opt(ctx, DAX_ALWAYS);
+		return true;
+	default:
+		DBG_BUGON(1);
+		return false;
+	}
+#else
+	errorfc(fc, "dax options not supported");
+	return false;
+#endif
+}
+
 static int erofs_fc_parse_param(struct fs_context *fc,
 				struct fs_parameter *param)
 {
@@ -412,6 +448,14 @@ static int erofs_fc_parse_param(struct fs_context *fc,
 		errorfc(fc, "compression not supported, cache_strategy ignored");
 #endif
 		break;
+	case Opt_dax:
+		if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS))
+			return -EINVAL;
+		break;
+	case Opt_dax_enum:
+		if (!erofs_fc_set_dax_mode(fc, result.uint_32))
+			return -EINVAL;
+		break;
 	default:
 		return -ENOPARAM;
 	}
@@ -496,10 +540,16 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
 		return -ENOMEM;
 
 	sb->s_fs_info = sbi;
+	sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 	err = erofs_read_superblock(sb);
 	if (err)
 		return err;
 
+	if (test_opt(ctx, DAX_ALWAYS) &&
+	    !bdev_dax_supported(sb->s_bdev, EROFS_BLKSIZ)) {
+		errorfc(fc, "DAX unsupported by block device. Turning off DAX.");
+		clear_opt(ctx, DAX_ALWAYS);
+	}
 	sb->s_flags |= SB_RDONLY | SB_NOATIME;
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	sb->s_time_gran = 1;
@@ -609,6 +659,7 @@ static void erofs_kill_sb(struct super_block *sb)
 	sbi = EROFS_SB(sb);
 	if (!sbi)
 		return;
+	fs_put_dax(sbi->dax_dev);
 	kfree(sbi);
 	sb->s_fs_info = NULL;
 }
@@ -711,8 +762,8 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 {
-	struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb);
-	struct erofs_fs_context *ctx __maybe_unused = &sbi->ctx;
+	struct erofs_sb_info *sbi = EROFS_SB(root->d_sb);
+	struct erofs_fs_context *ctx = &sbi->ctx;
 
 #ifdef CONFIG_EROFS_FS_XATTR
 	if (test_opt(ctx, XATTR_USER))
@@ -734,6 +785,10 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root)
 	else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
 		seq_puts(seq, ",cache_strategy=readaround");
 #endif
+	if (test_opt(ctx, DAX_ALWAYS))
+		seq_puts(seq, ",dax=always");
+	if (test_opt(ctx, DAX_NEVER))
+		seq_puts(seq, ",dax=never");
 	return 0;
 }
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-10-14 10:18:11 +0000