[PATCH 5.10 009/147] gfs2: Turn gfs2_extent_map into gfs2_{get,alloc}_extent

Sasha Levin
2026-02-28T18:17:44Z

From: Andreas Gruenbacher <agruenba@redhat.com>

[ Upstream commit 9153dac13a6966b63183bac450d5cd39b07cc85c ]

Convert gfs2_extent_map to iomap and split it into gfs2_get_extent and
gfs2_alloc_extent. Instead of hardcoding the extent size, pass it in
via the extlen parameter.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Stable-dep-of: faddeb848305 ("gfs2: Fix use-after-free in iomap inline data write path")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/gfs2/bmap.c | 59 ++++++++++++++++++++++++++++++----------------
fs/gfs2/bmap.h | 6 +++--
fs/gfs2/dir.c | 13 +++++-----
fs/gfs2/quota.c | 4 ++--
fs/gfs2/recovery.c | 4 ++--
5 files changed, 53 insertions(+), 33 deletions(-)

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 8ec1114ab452c..41e98499862db 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1316,28 +1316,47 @@ int gfs2_block_map(struct inode *inode, sector_t lblock,
return ret;
}

-/*
- * Deprecated: do not use in new code
- */
-int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)
+int gfs2_get_extent(struct inode *inode, u64 lblock, u64 *dblock,
+ unsigned int *extlen)
{
- struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 };
+ unsigned int blkbits = inode->i_blkbits;
+ struct iomap iomap = { };
+ unsigned int len;
int ret;
- int create = *new;
-
- BUG_ON(!extlen);
- BUG_ON(!dblock);
- BUG_ON(!new);
-
- bh.b_size = BIT(inode->i_blkbits + (create ? 0 : 5));
- ret = gfs2_block_map(inode, lblock, &bh, create);
- *extlen = bh.b_size >> inode->i_blkbits;
- *dblock = bh.b_blocknr;
- if (buffer_new(&bh))
- *new = 1;
- else
- *new = 0;
- return ret;
+
+ ret = gfs2_iomap_get(inode, lblock << blkbits, *extlen << blkbits,
+ &iomap);
+ if (ret)
+ return ret;
+ if (iomap.type != IOMAP_MAPPED)
+ return -EIO;
+ *dblock = iomap.addr >> blkbits;
+ len = iomap.length >> blkbits;
+ if (len < *extlen)
+ *extlen = len;
+ return 0;
+}
+
+int gfs2_alloc_extent(struct inode *inode, u64 lblock, u64 *dblock,
+ unsigned int *extlen, bool *new)
+{
+ unsigned int blkbits = inode->i_blkbits;
+ struct iomap iomap = { };
+ unsigned int len;
+ int ret;
+
+ ret = gfs2_iomap_alloc(inode, lblock << blkbits, *extlen << blkbits,
+ &iomap);
+ if (ret)
+ return ret;
+ if (iomap.type != IOMAP_MAPPED)
+ return -EIO;
+ *dblock = iomap.addr >> blkbits;
+ len = iomap.length >> blkbits;
+ if (len < *extlen)
+ *extlen = len;
+ *new = iomap.flags & IOMAP_F_NEW;
+ return 0;
}

/*
diff --git a/fs/gfs2/bmap.h b/fs/gfs2/bmap.h
index c63efee8aaa43..67ef7cf7fdacc 100644
--- a/fs/gfs2/bmap.h
+++ b/fs/gfs2/bmap.h
@@ -53,8 +53,10 @@ extern int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
struct iomap *iomap);
extern int gfs2_iomap_alloc(struct inode *inode, loff_t pos, loff_t length,
struct iomap *iomap);
-extern int gfs2_extent_map(struct inode *inode, u64 lblock, int *new,
- u64 *dblock, unsigned *extlen);
+extern int gfs2_get_extent(struct inode *inode, u64 lblock, u64 *dblock,
+ unsigned int *extlen);
+extern int gfs2_alloc_extent(struct inode *inode, u64 lblock, u64 *dblock,
+ unsigned *extlen, bool *new);
extern int gfs2_setattr_size(struct inode *inode, u64 size);
extern void gfs2_trim_blocks(struct inode *inode);
extern int gfs2_truncatei_resume(struct gfs2_inode *ip);
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index c0f2875c946c9..4517ffb7c13d2 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -159,7 +159,7 @@ static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
unsigned int o;
int copied = 0;
int error = 0;
- int new = 0;
+ bool new = false;

if (!size)
return 0;
@@ -189,9 +189,9 @@ static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
amount = sdp->sd_sb.sb_bsize - o;

if (!extlen) {
- new = 1;
- error = gfs2_extent_map(&ip->i_inode, lblock, &new,
- &dblock, &extlen);
+ extlen = 1;
+ error = gfs2_alloc_extent(&ip->i_inode, lblock, &dblock,
+ &extlen, &new);
if (error)
goto fail;
error = -EIO;
@@ -286,15 +286,14 @@ static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
while (copied < size) {
unsigned int amount;
struct buffer_head *bh;
- int new;

amount = size - copied;
if (amount > sdp->sd_sb.sb_bsize - o)
amount = sdp->sd_sb.sb_bsize - o;

if (!extlen) {
- new = 0;
- error = gfs2_extent_map(&ip->i_inode, lblock, &new,
+ extlen = 32;
+ error = gfs2_get_extent(&ip->i_inode, lblock,
&dblock, &extlen);
if (error || !dblock)
goto fail;
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 8c226aa286336..984ca5057d9d5 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -1394,8 +1394,8 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
unsigned int y;

if (!extlen) {
- int new = 0;
- error = gfs2_extent_map(&ip->i_inode, x, &new, &dblock, &extlen);
+ extlen = 32;
+ error = gfs2_get_extent(&ip->i_inode, x, &dblock, &extlen);
if (error)
goto fail;
}
diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index 8f9c6480a5df4..b925ba068af50 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -34,12 +34,12 @@ int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
{
struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
struct gfs2_glock *gl = ip->i_gl;
- int new = 0;
u64 dblock;
u32 extlen;
int error;

- error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
+ extlen = 32;
+ error = gfs2_get_extent(&ip->i_inode, blk, &dblock, &extlen);
if (error)
return error;
if (!dblock) {
--
2.51.0