Commit 24c19ef4 authored by Mark Fasheh's avatar Mark Fasheh

ocfs2: Remove i_generation from inode lock names

OCFS2 puts inode meta data in the "lock value block" provided by the DLM.
Typically, i_generation is encoded in the lock name so that a deleted inode
on and a new one in the same block don't share the same lvb.

Unfortunately, that scheme means that the read in ocfs2_read_locked_inode()
is potentially thrown away as soon as the meta data lock is taken - we
cannot encode the lock name without first knowing i_generation, which
requires a disk read.

This patch encodes i_generation in the inode meta data lvb, and removes the
value from the inode meta data lock name. This way, the read can be covered
by a lock, and at the same time we can distinguish between an up to date and
a stale LVB.

This will help cold-cache stat(2) performance in particular.

Since this patch changes the protocol version, we take the opportunity to do
a minor re-organization of two of the LVB fields.
Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
parent f9e2d82e
......@@ -44,6 +44,9 @@
* locking semantics of the file system using the protocol. It should
* be somewhere else, I'm sure, but right now it isn't.
*
* New in version 4:
* - Remove i_generation from lock names for better stat performance.
*
* New in version 3:
* - Replace dentry votes with a cluster lock
*
......@@ -51,7 +54,7 @@
* - full 64 bit i_size in the metadata lock lvbs
* - introduction of "rw" lock and pushing meta/data locking down
*/
#define O2NET_PROTOCOL_VERSION 3ULL
#define O2NET_PROTOCOL_VERSION 4ULL
struct o2net_handshake {
__be64 protocol_version;
__be64 connector_id;
......
......@@ -320,6 +320,7 @@ void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
enum ocfs2_lock_type type,
unsigned int generation,
struct inode *inode)
{
struct ocfs2_lock_res_ops *ops;
......@@ -341,7 +342,7 @@ void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
};
ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
inode->i_generation, res->l_name);
generation, res->l_name);
ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
}
......@@ -1173,17 +1174,19 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
int ocfs2_create_new_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres,
int ex)
int ex,
int local)
{
int level = ex ? LKM_EXMODE : LKM_PRMODE;
unsigned long flags;
int lkm_flags = local ? LKM_LOCAL : 0;
spin_lock_irqsave(&lockres->l_lock, flags);
BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
spin_unlock_irqrestore(&lockres->l_lock, flags);
return ocfs2_lock_create(osb, lockres, level, LKM_LOCAL);
return ocfs2_lock_create(osb, lockres, level, lkm_flags);
}
/* Grants us an EX lock on the data and metadata resources, skipping
......@@ -1212,19 +1215,23 @@ int ocfs2_create_new_inode_locks(struct inode *inode)
* on a resource which has an invalid one -- we'll set it
* valid when we release the EX. */
ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1);
ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
if (ret) {
mlog_errno(ret);
goto bail;
}
ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1);
/*
* We don't want to use LKM_LOCAL on a meta data lock as they
* don't use a generation in their lock names.
*/
ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_meta_lockres, 1, 0);
if (ret) {
mlog_errno(ret);
goto bail;
}
ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1);
ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_data_lockres, 1, 1);
if (ret) {
mlog_errno(ret);
goto bail;
......@@ -1413,6 +1420,16 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
/*
* Invalidate the LVB of a deleted inode - this way other
* nodes are forced to go to disk and discover the new inode
* status.
*/
if (oi->ip_flags & OCFS2_INODE_DELETED) {
lvb->lvb_version = 0;
goto out;
}
lvb->lvb_version = OCFS2_LVB_VERSION;
lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
......@@ -1429,6 +1446,7 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
out:
mlog_meta_lvb(0, lockres);
mlog_exit_void();
......@@ -1727,6 +1745,18 @@ int ocfs2_meta_lock_full(struct inode *inode,
wait_event(osb->recovery_event,
ocfs2_node_map_is_empty(osb, &osb->recovery_map));
/*
* We only see this flag if we're being called from
* ocfs2_read_locked_inode(). It means we're locking an inode
* which hasn't been populated yet, so clear the refresh flag
* and let the caller handle it.
*/
if (inode->i_state & I_NEW) {
status = 0;
ocfs2_complete_lock_res_refresh(lockres, 0);
goto bail;
}
/* This is fun. The caller may want a bh back, or it may
* not. ocfs2_meta_lock_update definitely wants one in, but
* may or may not read one, depending on what's in the
......
......@@ -32,9 +32,9 @@
#define OCFS2_LVB_VERSION 4
struct ocfs2_meta_lvb {
__be16 lvb_reserved0;
__u8 lvb_reserved1;
__u8 lvb_version;
__u8 lvb_reserved0;
__be16 lvb_reserved1;
__be32 lvb_iclusters;
__be32 lvb_iuid;
__be32 lvb_igid;
......@@ -62,13 +62,14 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb);
void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res);
void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
enum ocfs2_lock_type type,
unsigned int generation,
struct inode *inode);
void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
u64 parent, struct inode *inode);
void ocfs2_lock_res_free(struct ocfs2_lock_res *res);
int ocfs2_create_new_inode_locks(struct inode *inode);
int ocfs2_create_new_lock(struct ocfs2_super *osb,
struct ocfs2_lock_res *lockres, int ex);
struct ocfs2_lock_res *lockres, int ex, int local);
int ocfs2_drop_inode_locks(struct inode *inode);
int ocfs2_data_lock_full(struct inode *inode,
int write,
......
......@@ -58,7 +58,7 @@ static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp)
return ERR_PTR(-ESTALE);
}
inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno);
inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno, 0);
if (IS_ERR(inode)) {
mlog_errno(PTR_ERR(inode));
......@@ -115,7 +115,7 @@ static struct dentry *ocfs2_get_parent(struct dentry *child)
goto bail_unlock;
}
inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno);
inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0);
if (IS_ERR(inode)) {
mlog(ML_ERROR, "Unable to create inode %llu\n",
(unsigned long long)blkno);
......
......@@ -54,8 +54,6 @@
#include "buffer_head_io.h"
#define OCFS2_FI_FLAG_NOWAIT 0x1
#define OCFS2_FI_FLAG_DELETE 0x2
struct ocfs2_find_inode_args
{
u64 fi_blkno;
......@@ -109,7 +107,7 @@ struct inode *ocfs2_ilookup_for_vote(struct ocfs2_super *osb,
return ilookup5(osb->sb, args.fi_ino, ocfs2_find_actor, &args);
}
struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno)
struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno, int flags)
{
struct inode *inode = NULL;
struct super_block *sb = osb->sb;
......@@ -127,7 +125,7 @@ struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 blkno)
}
args.fi_blkno = blkno;
args.fi_flags = 0;
args.fi_flags = flags;
args.fi_ino = ino_from_blkno(sb, blkno);
inode = iget5_locked(sb, args.fi_ino, ocfs2_find_actor,
......@@ -297,15 +295,11 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
OCFS2_I(inode)->ip_orphaned_slot = OCFS2_INVALID_SLOT;
OCFS2_I(inode)->ip_attr = le32_to_cpu(fe->i_attr);
if (create_ino)
inode->i_ino = ino_from_blkno(inode->i_sb,
le64_to_cpu(fe->i_blkno));
mlog(0, "blkno = %llu, ino = %lu, create_ino = %s\n",
(unsigned long long)fe->i_blkno, inode->i_ino, create_ino ? "true" : "false");
inode->i_nlink = le16_to_cpu(fe->i_links_count);
if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL))
OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE;
if (fe->i_flags & cpu_to_le32(OCFS2_LOCAL_ALLOC_FL)) {
OCFS2_I(inode)->ip_flags |= OCFS2_INODE_BITMAP;
mlog(0, "local alloc inode: i_ino=%lu\n", inode->i_ino);
......@@ -343,12 +337,28 @@ int ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
break;
}
if (create_ino) {
inode->i_ino = ino_from_blkno(inode->i_sb,
le64_to_cpu(fe->i_blkno));
/*
* If we ever want to create system files from kernel,
* the generation argument to
* ocfs2_inode_lock_res_init() will have to change.
*/
BUG_ON(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL));
ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
OCFS2_LOCK_TYPE_META, 0, inode);
}
ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_rw_lockres,
OCFS2_LOCK_TYPE_RW, inode);
ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
OCFS2_LOCK_TYPE_META, inode);
OCFS2_LOCK_TYPE_RW, inode->i_generation,
inode);
ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_data_lockres,
OCFS2_LOCK_TYPE_DATA, inode);
OCFS2_LOCK_TYPE_DATA, inode->i_generation,
inode);
ocfs2_set_inode_flags(inode);
inode->i_flags |= S_NOATIME;
......@@ -366,15 +376,15 @@ static int ocfs2_read_locked_inode(struct inode *inode,
struct ocfs2_super *osb;
struct ocfs2_dinode *fe;
struct buffer_head *bh = NULL;
int status;
int sysfile = 0;
int status, can_lock;
u32 generation = 0;
mlog_entry("(0x%p, 0x%p)\n", inode, args);
status = -EINVAL;
if (inode == NULL || inode->i_sb == NULL) {
mlog(ML_ERROR, "bad inode\n");
goto bail;
return status;
}
sb = inode->i_sb;
osb = OCFS2_SB(sb);
......@@ -382,50 +392,110 @@ static int ocfs2_read_locked_inode(struct inode *inode,
if (!args) {
mlog(ML_ERROR, "bad inode args\n");
make_bad_inode(inode);
goto bail;
return status;
}
/* Read the FE off disk. This is safe because the kernel only
* does one read_inode2 for a new inode, and if it doesn't
* exist yet then nobody can be working on it! */
status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0, NULL);
/*
* To improve performance of cold-cache inode stats, we take
* the cluster lock here if possible.
*
* Generally, OCFS2 never trusts the contents of an inode
* unless it's holding a cluster lock, so taking it here isn't
* a correctness issue as much as it is a performance
* improvement.
*
* There are three times when taking the lock is not a good idea:
*
* 1) During startup, before we have initialized the DLM.
*
* 2) If we are reading certain system files which never get
* cluster locks (local alloc, truncate log).
*
* 3) If the process doing the iget() is responsible for
* orphan dir recovery. We're holding the orphan dir lock and
* can get into a deadlock with another process on another
* node in ->delete_inode().
*
* #1 and #2 can be simply solved by never taking the lock
* here for system files (which are the only type we read
* during mount). It's a heavier approach, but our main
* concern is user-accesible files anyway.
*
* #3 works itself out because we'll eventually take the
* cluster lock before trusting anything anyway.
*/
can_lock = !(args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
&& !(args->fi_flags & OCFS2_FI_FLAG_NOLOCK);
/*
* To maintain backwards compatibility with older versions of
* ocfs2-tools, we still store the generation value for system
* files. The only ones that actually matter to userspace are
* the journals, but it's easier and inexpensive to just flag
* all system files similarly.
*/
if (args->fi_flags & OCFS2_FI_FLAG_SYSFILE)
generation = osb->fs_generation;
ocfs2_inode_lock_res_init(&OCFS2_I(inode)->ip_meta_lockres,
OCFS2_LOCK_TYPE_META,
generation, inode);
if (can_lock) {
status = ocfs2_meta_lock(inode, NULL, NULL, 0);
if (status) {
make_bad_inode(inode);
mlog_errno(status);
return status;
}
}
status = ocfs2_read_block(osb, args->fi_blkno, &bh, 0,
can_lock ? inode : NULL);
if (status < 0) {
mlog_errno(status);
make_bad_inode(inode);
goto bail;
}
status = -EINVAL;
fe = (struct ocfs2_dinode *) bh->b_data;
if (!OCFS2_IS_VALID_DINODE(fe)) {
mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
(unsigned long long)fe->i_blkno, 7, fe->i_signature);
make_bad_inode(inode);
goto bail;
}
if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL))
sysfile = 1;
/*
* This is a code bug. Right now the caller needs to
* understand whether it is asking for a system file inode or
* not so the proper lock names can be built.
*/
mlog_bug_on_msg(!!(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) !=
!!(args->fi_flags & OCFS2_FI_FLAG_SYSFILE),
"Inode %llu: system file state is ambigous\n",
(unsigned long long)args->fi_blkno);
if (S_ISCHR(le16_to_cpu(fe->i_mode)) ||
S_ISBLK(le16_to_cpu(fe->i_mode)))
inode->i_rdev = huge_decode_dev(le64_to_cpu(fe->id1.dev1.i_rdev));
status = -EINVAL;
if (ocfs2_populate_inode(inode, fe, 0) < 0) {
mlog(ML_ERROR, "populate failed! i_blkno=%llu, i_ino=%lu\n",
(unsigned long long)fe->i_blkno, inode->i_ino);
make_bad_inode(inode);
goto bail;
}
BUG_ON(args->fi_blkno != le64_to_cpu(fe->i_blkno));
if (sysfile)
OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE;
status = 0;
bail:
if (can_lock)
ocfs2_meta_unlock(inode, 0);
if (status < 0)
make_bad_inode(inode);
if (args && bh)
brelse(bh);
......@@ -898,9 +968,15 @@ void ocfs2_delete_inode(struct inode *inode)
goto bail_unlock_inode;
}
/* Mark the inode as successfully deleted. This is important
* for ocfs2_clear_inode as it will check this flag and skip
* any checkpointing work */
/*
* Mark the inode as successfully deleted.
*
* This is important for ocfs2_clear_inode() as it will check
* this flag and skip any checkpointing work
*
* ocfs2_stuff_meta_lvb() also uses this flag to invalidate
* the LVB for other nodes.
*/
OCFS2_I(inode)->ip_flags |= OCFS2_INODE_DELETED;
bail_unlock_inode:
......
......@@ -122,7 +122,13 @@ struct buffer_head *ocfs2_bread(struct inode *inode, int block,
void ocfs2_clear_inode(struct inode *inode);
void ocfs2_delete_inode(struct inode *inode);
void ocfs2_drop_inode(struct inode *inode);
struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff);
/* Flags for ocfs2_iget() */
#define OCFS2_FI_FLAG_NOWAIT 0x1
#define OCFS2_FI_FLAG_DELETE 0x2
#define OCFS2_FI_FLAG_SYSFILE 0x4
#define OCFS2_FI_FLAG_NOLOCK 0x8
struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff, int flags);
struct inode *ocfs2_ilookup_for_vote(struct ocfs2_super *osb,
u64 blkno,
int delete_vote);
......
......@@ -1493,7 +1493,8 @@ static int ocfs2_queue_orphans(struct ocfs2_super *osb,
if (de->name_len == 2 && !strncmp("..", de->name, 2))
continue;
iter = ocfs2_iget(osb, le64_to_cpu(de->inode));
iter = ocfs2_iget(osb, le64_to_cpu(de->inode),
OCFS2_FI_FLAG_NOLOCK);
if (IS_ERR(iter))
continue;
......
......@@ -179,7 +179,7 @@ static struct dentry *ocfs2_lookup(struct inode *dir, struct dentry *dentry,
if (status < 0)
goto bail_add;
inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno);
inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0);
if (IS_ERR(inode)) {
mlog(ML_ERROR, "Unable to create inode %llu\n",
(unsigned long long)blkno);
......
......@@ -202,7 +202,7 @@ static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb)
mlog_entry_void();
new = ocfs2_iget(osb, osb->root_blkno);
new = ocfs2_iget(osb, osb->root_blkno, OCFS2_FI_FLAG_SYSFILE);
if (IS_ERR(new)) {
status = PTR_ERR(new);
mlog_errno(status);
......@@ -210,7 +210,7 @@ static int ocfs2_init_global_system_inodes(struct ocfs2_super *osb)
}
osb->root_inode = new;
new = ocfs2_iget(osb, osb->system_dir_blkno);
new = ocfs2_iget(osb, osb->system_dir_blkno, OCFS2_FI_FLAG_SYSFILE);
if (IS_ERR(new)) {
status = PTR_ERR(new);
mlog_errno(status);
......
......@@ -115,7 +115,7 @@ static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
goto bail;
}
inode = ocfs2_iget(osb, blkno);
inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE);
if (IS_ERR(inode)) {
mlog_errno(PTR_ERR(inode));
inode = NULL;
......
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