[PATCH 19/48] [GFS2] Shrink & rename di_depth

From: swhiteho
Date: Thu Apr 17 2008 - 05:42:00 EST


From: Steven Whitehouse <swhiteho@xxxxxxxxxx>

This patch forms a pair with the previous patch which shrunk
di_height. Like that patch di_depth is renamed i_depth and moved
into struct gfs2_inode directly. Also the field goes from 16 bits
to 8 bits since it is also limited to a max value which is rather
small (17 in this case). In addition we also now validate the field
against this maximum value when its read in.

Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 78c236f..081daa9 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -757,7 +757,7 @@ static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,

if (ip->i_di.di_flags & GFS2_DIF_EXHASH) {
struct gfs2_leaf *leaf;
- unsigned hsize = 1 << ip->i_di.di_depth;
+ unsigned hsize = 1 << ip->i_depth;
unsigned index;
u64 ln;
if (hsize * sizeof(u64) != ip->i_di.di_size) {
@@ -765,7 +765,7 @@ static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
return ERR_PTR(-EIO);
}

- index = name->hash >> (32 - ip->i_di.di_depth);
+ index = name->hash >> (32 - ip->i_depth);
error = get_first_leaf(ip, index, &bh);
if (error)
return ERR_PTR(error);
@@ -910,7 +910,7 @@ static int dir_make_exhash(struct inode *inode)
dip->i_di.di_flags |= GFS2_DIF_EXHASH;

for (x = sdp->sd_hash_ptrs, y = -1; x; x >>= 1, y++) ;
- dip->i_di.di_depth = y;
+ dip->i_depth = y;

gfs2_dinode_out(dip, dibh->b_data);

@@ -941,7 +941,7 @@ static int dir_split_leaf(struct inode *inode, const struct qstr *name)
int x, moved = 0;
int error;

- index = name->hash >> (32 - dip->i_di.di_depth);
+ index = name->hash >> (32 - dip->i_depth);
error = get_leaf_nr(dip, index, &leaf_no);
if (error)
return error;
@@ -952,7 +952,7 @@ static int dir_split_leaf(struct inode *inode, const struct qstr *name)
return error;

oleaf = (struct gfs2_leaf *)obh->b_data;
- if (dip->i_di.di_depth == be16_to_cpu(oleaf->lf_depth)) {
+ if (dip->i_depth == be16_to_cpu(oleaf->lf_depth)) {
brelse(obh);
return 1; /* can't split */
}
@@ -967,10 +967,10 @@ static int dir_split_leaf(struct inode *inode, const struct qstr *name)
bn = nbh->b_blocknr;

/* Compute the start and len of leaf pointers in the hash table. */
- len = 1 << (dip->i_di.di_depth - be16_to_cpu(oleaf->lf_depth));
+ len = 1 << (dip->i_depth - be16_to_cpu(oleaf->lf_depth));
half_len = len >> 1;
if (!half_len) {
- printk(KERN_WARNING "di_depth %u lf_depth %u index %u\n", dip->i_di.di_depth, be16_to_cpu(oleaf->lf_depth), index);
+ printk(KERN_WARNING "i_depth %u lf_depth %u index %u\n", dip->i_depth, be16_to_cpu(oleaf->lf_depth), index);
gfs2_consist_inode(dip);
error = -EIO;
goto fail_brelse;
@@ -997,7 +997,7 @@ static int dir_split_leaf(struct inode *inode, const struct qstr *name)
kfree(lp);

/* Compute the divider */
- divider = (start + half_len) << (32 - dip->i_di.di_depth);
+ divider = (start + half_len) << (32 - dip->i_depth);

/* Copy the entries */
dirent_first(dip, obh, &dent);
@@ -1082,7 +1082,7 @@ static int dir_double_exhash(struct gfs2_inode *dip)
int x;
int error = 0;

- hsize = 1 << dip->i_di.di_depth;
+ hsize = 1 << dip->i_depth;
if (hsize * sizeof(u64) != dip->i_di.di_size) {
gfs2_consist_inode(dip);
return -EIO;
@@ -1125,7 +1125,7 @@ static int dir_double_exhash(struct gfs2_inode *dip)

error = gfs2_meta_inode_buffer(dip, &dibh);
if (!gfs2_assert_withdraw(sdp, !error)) {
- dip->i_di.di_depth++;
+ dip->i_depth++;
gfs2_dinode_out(dip, dibh->b_data);
brelse(dibh);
}
@@ -1370,14 +1370,14 @@ static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
int error = 0;
unsigned depth = 0;

- hsize = 1 << dip->i_di.di_depth;
+ hsize = 1 << dip->i_depth;
if (hsize * sizeof(u64) != dip->i_di.di_size) {
gfs2_consist_inode(dip);
return -EIO;
}

hash = gfs2_dir_offset2hash(*offset);
- index = hash >> (32 - dip->i_di.di_depth);
+ index = hash >> (32 - dip->i_depth);

lp = kmalloc(sdp->sd_hash_bsize, GFP_KERNEL);
if (!lp)
@@ -1405,7 +1405,7 @@ static int dir_e_read(struct inode *inode, u64 *offset, void *opaque,
if (error)
break;

- len = 1 << (dip->i_di.di_depth - depth);
+ len = 1 << (dip->i_depth - depth);
index = (index & ~(len - 1)) + len;
}

@@ -1549,7 +1549,7 @@ static int dir_new_leaf(struct inode *inode, const struct qstr *name)
u32 index;
u64 bn;

- index = name->hash >> (32 - ip->i_di.di_depth);
+ index = name->hash >> (32 - ip->i_depth);
error = get_first_leaf(ip, index, &obh);
if (error)
return error;
@@ -1641,7 +1641,7 @@ int gfs2_dir_add(struct inode *inode, const struct qstr *name,
continue;
if (error < 0)
break;
- if (ip->i_di.di_depth < GFS2_DIR_MAX_DEPTH) {
+ if (ip->i_depth < GFS2_DIR_MAX_DEPTH) {
error = dir_double_exhash(ip);
if (error)
break;
@@ -1785,7 +1785,7 @@ static int foreach_leaf(struct gfs2_inode *dip, leaf_call_t lc, void *data)
u64 leaf_no;
int error = 0;

- hsize = 1 << dip->i_di.di_depth;
+ hsize = 1 << dip->i_depth;
if (hsize * sizeof(u64) != dip->i_di.di_size) {
gfs2_consist_inode(dip);
return -EIO;
@@ -1817,7 +1817,7 @@ static int foreach_leaf(struct gfs2_inode *dip, leaf_call_t lc, void *data)
if (error)
goto out;
leaf = (struct gfs2_leaf *)bh->b_data;
- len = 1 << (dip->i_di.di_depth - be16_to_cpu(leaf->lf_depth));
+ len = 1 << (dip->i_depth - be16_to_cpu(leaf->lf_depth));
brelse(bh);

error = lc(dip, index, len, leaf_no, data);
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index e9c58dc..9dfdde3 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -246,7 +246,6 @@ struct gfs2_dinode_host {
u64 di_generation; /* generation number for NFS */
u32 di_flags; /* GFS2_DIF_... */
/* These only apply to directories */
- u16 di_depth; /* Number of bits in the table */
u32 di_entries; /* The number of entries in the directory */
u64 di_eattr; /* extended attribute block number */
};
@@ -267,6 +266,7 @@ struct gfs2_inode {

struct rw_semaphore i_rw_mutex;
u8 i_height;
+ u8 i_depth;
};

/*
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index db5961a..65fdfee 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -248,7 +248,7 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
{
struct gfs2_dinode_host *di = &ip->i_di;
const struct gfs2_dinode *str = buf;
- u16 height;
+ u16 height, depth;

if (unlikely(ip->i_no_addr != be64_to_cpu(str->di_num.no_addr)))
goto corrupt;
@@ -293,7 +293,10 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
goto corrupt;
ip->i_height = (u8)height;

- di->di_depth = be16_to_cpu(str->di_depth);
+ depth = be16_to_cpu(str->di_depth);
+ if (unlikely(depth > GFS2_DIR_MAX_DEPTH))
+ goto corrupt;
+ ip->i_depth = (u8)depth;
di->di_entries = be32_to_cpu(str->di_entries);

di->di_eattr = be64_to_cpu(str->di_eattr);
@@ -1410,7 +1413,7 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
!(ip->i_di.di_flags & GFS2_DIF_EXHASH) ?
GFS2_FORMAT_DE : 0);
- str->di_depth = cpu_to_be16(di->di_depth);
+ str->di_depth = cpu_to_be16(ip->i_depth);
str->di_entries = cpu_to_be32(di->di_entries);

str->di_eattr = cpu_to_be64(di->di_eattr);
@@ -1436,7 +1439,7 @@ void gfs2_dinode_print(const struct gfs2_inode *ip)
(unsigned long long)di->di_goal_data);
printk(KERN_INFO " di_flags = 0x%.8X\n", di->di_flags);
printk(KERN_INFO " i_height = %u\n", ip->i_height);
- printk(KERN_INFO " di_depth = %u\n", di->di_depth);
+ printk(KERN_INFO " i_depth = %u\n", ip->i_depth);
printk(KERN_INFO " di_entries = %u\n", di->di_entries);
printk(KERN_INFO " di_eattr = %llu\n",
(unsigned long long)di->di_eattr);
--
1.5.1.2

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