[PATCHv5 36/36] ext4, vfs: add huge= mount option

From: Kirill A. Shutemov
Date: Tue Nov 29 2016 - 06:28:58 EST


The same four values as in tmpfs case.

Encyption code is not yet ready to handle huge page, so we disable huge
pages support if the inode has EXT4_INODE_ENCRYPT.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
fs/ext4/ext4.h | 5 +++++
fs/ext4/inode.c | 30 +++++++++++++++++++++++-------
fs/ext4/super.c | 24 ++++++++++++++++++++++++
3 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index aff204f040fc..fb3f81863b53 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1133,6 +1133,11 @@ struct ext4_inode_info {
#define EXT4_MOUNT_DIOREAD_NOLOCK 0x400000 /* Enable support for dio read nolocking */
#define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */
#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
+#define EXT4_MOUNT_HUGE_MODE 0x6000000 /* Huge support mode: */
+#define EXT4_MOUNT_HUGE_NEVER 0x0000000
+#define EXT4_MOUNT_HUGE_ALWAYS 0x2000000
+#define EXT4_MOUNT_HUGE_WITHIN_SIZE 0x4000000
+#define EXT4_MOUNT_HUGE_ADVISE 0x6000000
#define EXT4_MOUNT_DELALLOC 0x8000000 /* Delalloc support */
#define EXT4_MOUNT_DATA_ERR_ABORT 0x10000000 /* Abort on file data write */
#define EXT4_MOUNT_BLOCK_VALIDITY 0x20000000 /* Block validity checking */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 17a767c21dc3..4c37fd9fb219 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4472,7 +4472,7 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
void ext4_set_inode_flags(struct inode *inode)
{
unsigned int flags = EXT4_I(inode)->i_flags;
- unsigned int new_fl = 0;
+ unsigned int mask, new_fl = 0;

if (flags & EXT4_SYNC_FL)
new_fl |= S_SYNC;
@@ -4484,12 +4484,28 @@ void ext4_set_inode_flags(struct inode *inode)
new_fl |= S_NOATIME;
if (flags & EXT4_DIRSYNC_FL)
new_fl |= S_DIRSYNC;
- if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode) &&
- !ext4_should_journal_data(inode) && !ext4_has_inline_data(inode) &&
- !ext4_encrypted_inode(inode))
- new_fl |= S_DAX;
- inode_set_flags(inode, new_fl,
- S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);
+ if (S_ISREG(inode->i_mode) && !ext4_encrypted_inode(inode)) {
+ if (test_opt(inode->i_sb, DAX) &&
+ !ext4_should_journal_data(inode) &&
+ !ext4_has_inline_data(inode))
+ new_fl |= S_DAX;
+ switch (test_opt(inode->i_sb, HUGE_MODE)) {
+ case EXT4_MOUNT_HUGE_NEVER:
+ break;
+ case EXT4_MOUNT_HUGE_ALWAYS:
+ new_fl |= S_HUGE_ALWAYS;
+ break;
+ case EXT4_MOUNT_HUGE_WITHIN_SIZE:
+ new_fl |= S_HUGE_WITHIN_SIZE;
+ break;
+ case EXT4_MOUNT_HUGE_ADVISE:
+ new_fl |= S_HUGE_ADVISE;
+ break;
+ }
+ }
+ mask = S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
+ S_DIRSYNC | S_DAX | S_HUGE_MODE;
+ inode_set_flags(inode, new_fl, mask);
}

/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 72b459d2b244..127ddfeae1e0 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1296,6 +1296,7 @@ enum {
Opt_dioread_nolock, Opt_dioread_lock,
Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
Opt_max_dir_size_kb, Opt_nojournal_checksum,
+ Opt_huge_never, Opt_huge_always, Opt_huge_within_size, Opt_huge_advise,
};

static const match_table_t tokens = {
@@ -1376,6 +1377,10 @@ static const match_table_t tokens = {
{Opt_init_itable, "init_itable"},
{Opt_noinit_itable, "noinit_itable"},
{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
+ {Opt_huge_never, "huge=never"},
+ {Opt_huge_always, "huge=always"},
+ {Opt_huge_within_size, "huge=within_size"},
+ {Opt_huge_advise, "huge=advise"},
{Opt_test_dummy_encryption, "test_dummy_encryption"},
{Opt_removed, "check=none"}, /* mount option from ext2/3 */
{Opt_removed, "nocheck"}, /* mount option from ext2/3 */
@@ -1494,6 +1499,11 @@ static int clear_qf_name(struct super_block *sb, int qtype)
#define MOPT_NO_EXT3 0x0200
#define MOPT_EXT4_ONLY (MOPT_NO_EXT2 | MOPT_NO_EXT3)
#define MOPT_STRING 0x0400
+#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#define MOPT_HUGE 0x1000
+#else
+#define MOPT_HUGE MOPT_NOSUPPORT
+#endif

static const struct mount_opts {
int token;
@@ -1581,6 +1591,10 @@ static const struct mount_opts {
{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
{Opt_max_dir_size_kb, 0, MOPT_GTE0},
+ {Opt_huge_never, EXT4_MOUNT_HUGE_NEVER, MOPT_HUGE},
+ {Opt_huge_always, EXT4_MOUNT_HUGE_ALWAYS, MOPT_HUGE},
+ {Opt_huge_within_size, EXT4_MOUNT_HUGE_WITHIN_SIZE, MOPT_HUGE},
+ {Opt_huge_advise, EXT4_MOUNT_HUGE_ADVISE, MOPT_HUGE},
{Opt_test_dummy_encryption, 0, MOPT_GTE0},
{Opt_err, 0, 0}
};
@@ -1662,6 +1676,16 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
} else
return -1;
}
+ if (MOPT_HUGE != MOPT_NOSUPPORT && m->flags & MOPT_HUGE) {
+ sbi->s_mount_opt &= ~EXT4_MOUNT_HUGE_MODE;
+ sbi->s_mount_opt |= m->mount_opt;
+ if (m->mount_opt) {
+ ext4_msg(sb, KERN_WARNING, "Warning: "
+ "Support of huge pages is EXPERIMENTAL,"
+ " use at your own risk");
+ }
+ return 1;
+ }
if (m->flags & MOPT_CLEAR_ERR)
clear_opt(sb, ERRORS_MASK);
if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
--
2.10.2