Commit 1a0eae88 authored by Bob Peterson's avatar Bob Peterson Committed by Steven Whitehouse

GFS2: glock livelock

This patch fixes a couple gfs2 problems with the reclaiming of
unlinked dinodes.  First, there were a couple of livelocks where
everything would come to a halt waiting for a glock that was
seemingly held by a process that no longer existed.  In fact, the
process did exist, it just had the wrong pid number in the holder
information.  Second, there was a lock ordering problem between
inode locking and glock locking.  Third, glock/inode contention
could sometimes cause inodes to be improperly marked invalid by
iget_failed.
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 602c89d2
......@@ -1475,7 +1475,7 @@ struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
inode = gfs2_inode_lookup(dir->i_sb,
be16_to_cpu(dent->de_type),
be64_to_cpu(dent->de_inum.no_addr),
be64_to_cpu(dent->de_inum.no_formal_ino), 0);
be64_to_cpu(dent->de_inum.no_formal_ino));
brelse(bh);
return inode;
}
......
......@@ -169,7 +169,7 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb,
if (error)
goto fail;
inode = gfs2_inode_lookup(sb, DT_UNKNOWN, inum->no_addr, 0, 0);
inode = gfs2_inode_lookup(sb, DT_UNKNOWN, inum->no_addr, 0);
if (IS_ERR(inode)) {
error = PTR_ERR(inode);
goto fail;
......
......@@ -855,6 +855,9 @@ void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *
gh->gh_flags = flags;
gh->gh_iflags = 0;
gh->gh_ip = (unsigned long)__builtin_return_address(0);
if (gh->gh_owner_pid)
put_pid(gh->gh_owner_pid);
gh->gh_owner_pid = get_pid(task_pid(current));
}
/**
......
......@@ -158,7 +158,6 @@ void gfs2_set_iop(struct inode *inode)
* @sb: The super block
* @no_addr: The inode number
* @type: The type of the inode
* @skip_freeing: set this not return an inode if it is currently being freed.
*
* Returns: A VFS inode, or an error
*/
......@@ -166,17 +165,14 @@ void gfs2_set_iop(struct inode *inode)
struct inode *gfs2_inode_lookup(struct super_block *sb,
unsigned int type,
u64 no_addr,
u64 no_formal_ino, int skip_freeing)
u64 no_formal_ino)
{
struct inode *inode;
struct gfs2_inode *ip;
struct gfs2_glock *io_gl;
int error;
if (skip_freeing)
inode = gfs2_iget_skip(sb, no_addr);
else
inode = gfs2_iget(sb, no_addr);
inode = gfs2_iget(sb, no_addr);
ip = GFS2_I(inode);
if (!inode)
......@@ -234,13 +230,100 @@ fail_glock:
fail_iopen:
gfs2_glock_put(io_gl);
fail_put:
ip->i_gl->gl_object = NULL;
if (inode->i_state & I_NEW)
ip->i_gl->gl_object = NULL;
gfs2_glock_put(ip->i_gl);
fail:
iget_failed(inode);
if (inode->i_state & I_NEW)
iget_failed(inode);
else
iput(inode);
return ERR_PTR(error);
}
/**
* gfs2_unlinked_inode_lookup - Lookup an unlinked inode for reclamation
* @sb: The super block
* no_addr: The inode number
* @@inode: A pointer to the inode found, if any
*
* Returns: 0 and *inode if no errors occurred. If an error occurs,
* the resulting *inode may or may not be NULL.
*/
int gfs2_unlinked_inode_lookup(struct super_block *sb, u64 no_addr,
struct inode **inode)
{
struct gfs2_sbd *sdp;
struct gfs2_inode *ip;
struct gfs2_glock *io_gl;
int error;
struct gfs2_holder gh;
*inode = gfs2_iget_skip(sb, no_addr);
if (!(*inode))
return -ENOBUFS;
if (!((*inode)->i_state & I_NEW))
return -ENOBUFS;
ip = GFS2_I(*inode);
sdp = GFS2_SB(*inode);
ip->i_no_formal_ino = -1;
error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
if (unlikely(error))
goto fail;
ip->i_gl->gl_object = ip;
error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
if (unlikely(error))
goto fail_put;
set_bit(GIF_INVALID, &ip->i_flags);
error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, LM_FLAG_TRY | GL_EXACT,
&ip->i_iopen_gh);
if (unlikely(error)) {
if (error == GLR_TRYFAILED)
error = 0;
goto fail_iopen;
}
ip->i_iopen_gh.gh_gl->gl_object = ip;
gfs2_glock_put(io_gl);
(*inode)->i_mode = DT2IF(DT_UNKNOWN);
/*
* We must read the inode in order to work out its type in
* this case. Note that this doesn't happen often as we normally
* know the type beforehand. This code path only occurs during
* unlinked inode recovery (where it is safe to do this glock,
* which is not true in the general case).
*/
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, LM_FLAG_TRY,
&gh);
if (unlikely(error)) {
if (error == GLR_TRYFAILED)
error = 0;
goto fail_glock;
}
/* Inode is now uptodate */
gfs2_glock_dq_uninit(&gh);
gfs2_set_iop(*inode);
return 0;
fail_glock:
gfs2_glock_dq(&ip->i_iopen_gh);
fail_iopen:
gfs2_glock_put(io_gl);
fail_put:
ip->i_gl->gl_object = NULL;
gfs2_glock_put(ip->i_gl);
fail:
return error;
}
static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
{
const struct gfs2_dinode *str = buf;
......@@ -862,7 +945,7 @@ struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,
goto fail_gunlock2;
inode = gfs2_inode_lookup(dir->i_sb, IF2DT(mode), inum.no_addr,
inum.no_formal_ino, 0);
inum.no_formal_ino);
if (IS_ERR(inode))
goto fail_gunlock2;
......
......@@ -83,8 +83,9 @@ static inline void gfs2_inum_out(const struct gfs2_inode *ip,
extern void gfs2_set_iop(struct inode *inode);
extern struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned type,
u64 no_addr, u64 no_formal_ino,
int skip_freeing);
u64 no_addr, u64 no_formal_ino);
extern int gfs2_unlinked_inode_lookup(struct super_block *sb, u64 no_addr,
struct inode **inode);
extern struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr);
extern int gfs2_inode_refresh(struct gfs2_inode *ip);
......
......@@ -487,7 +487,7 @@ static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
struct dentry *dentry;
struct inode *inode;
inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0);
if (IS_ERR(inode)) {
fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
return PTR_ERR(inode);
......
......@@ -948,18 +948,20 @@ static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al)
* try_rgrp_unlink - Look for any unlinked, allocated, but unused inodes
* @rgd: The rgrp
*
* Returns: The inode, if one has been found
* Returns: 0 if no error
* The inode, if one has been found, in inode.
*/
static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked,
u64 skip)
static int try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked,
u64 skip, struct inode **inode)
{
struct inode *inode;
u32 goal = 0, block;
u64 no_addr;
struct gfs2_sbd *sdp = rgd->rd_sbd;
unsigned int n;
int error = 0;
*inode = NULL;
for(;;) {
if (goal >= rgd->rd_data)
break;
......@@ -979,14 +981,14 @@ static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked,
if (no_addr == skip)
continue;
*last_unlinked = no_addr;
inode = gfs2_inode_lookup(rgd->rd_sbd->sd_vfs, DT_UNKNOWN,
no_addr, -1, 1);
if (!IS_ERR(inode))
return inode;
error = gfs2_unlinked_inode_lookup(rgd->rd_sbd->sd_vfs,
no_addr, inode);
if (*inode || error)
return error;
}
rgd->rd_flags &= ~GFS2_RDF_CHECK;
return NULL;
return 0;
}
/**
......@@ -1096,12 +1098,27 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked)
case 0:
if (try_rgrp_fit(rgd, al))
goto out;
if (rgd->rd_flags & GFS2_RDF_CHECK)
inode = try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr);
/* If the rg came in already locked, there's no
way we can recover from a failed try_rgrp_unlink
because that would require an iput which can only
happen after the rgrp is unlocked. */
if (!rg_locked && rgd->rd_flags & GFS2_RDF_CHECK)
error = try_rgrp_unlink(rgd, last_unlinked,
ip->i_no_addr, &inode);
if (!rg_locked)
gfs2_glock_dq_uninit(&al->al_rgd_gh);
if (inode)
if (inode) {
if (error) {
if (inode->i_state & I_NEW)
iget_failed(inode);
else
iput(inode);
return ERR_PTR(error);
}
return inode;
}
if (error)
return ERR_PTR(error);
/* fall through */
case GLR_TRYFAILED:
rgd = recent_rgrp_next(rgd);
......@@ -1130,12 +1147,23 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked)
case 0:
if (try_rgrp_fit(rgd, al))
goto out;
if (rgd->rd_flags & GFS2_RDF_CHECK)
inode = try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr);
if (!rg_locked && rgd->rd_flags & GFS2_RDF_CHECK)
error = try_rgrp_unlink(rgd, last_unlinked,
ip->i_no_addr, &inode);
if (!rg_locked)
gfs2_glock_dq_uninit(&al->al_rgd_gh);
if (inode)
if (inode) {
if (error) {
if (inode->i_state & I_NEW)
iget_failed(inode);
else
iput(inode);
return ERR_PTR(error);
}
return inode;
}
if (error)
return ERR_PTR(error);
break;
case GLR_TRYFAILED:
......
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