[PATCH v3 2/3] udf: refactor udf_next_aext() to handle error

From: Zhao Mengmeng
Date: Tue Oct 01 2024 - 07:57:50 EST

From: Zhao Mengmeng <zhaomengmeng@xxxxxxxxxx>

Since udf_current_aext() has error handling, udf_next_aext() should have
error handling too. Besides, when too many indirect extents found in one
inode, return -EFSCORRUPTED; when reading block failed, return -EIO.

Signed-off-by: Zhao Mengmeng <zhaomengmeng@xxxxxxxxxx>
Suggested-by: Jan Kara <jack@xxxxxxx>
---
fs/udf/balloc.c | 27 ++++++++----
fs/udf/directory.c | 10 ++++-
fs/udf/inode.c | 108 ++++++++++++++++++++++++++++++---------------
fs/udf/super.c | 3 +-
fs/udf/truncate.c | 25 ++++++++---
fs/udf/udfdecl.h | 5 ++-
6 files changed, 122 insertions(+), 56 deletions(-)

diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c
index d8fc11765d61..efa110545e59 100644
--- a/fs/udf/balloc.c
+++ b/fs/udf/balloc.c
@@ -370,6 +370,7 @@ static void udf_table_free_blocks(struct super_block *sb,
struct extent_position oepos, epos;
int8_t etype;
struct udf_inode_info *iinfo;
+ int err = 0;

mutex_lock(&sbi->s_alloc_mutex);
iinfo = UDF_I(table);
@@ -383,8 +384,8 @@ static void udf_table_free_blocks(struct super_block *sb,
epos.block = oepos.block = iinfo->i_location;
epos.bh = oepos.bh = NULL;

- while (count &&
- (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+ while (count && ((err = udf_next_aext(table, &epos, &eloc, &elen,
+ &etype, 1)) == 1)) {
if (((eloc.logicalBlockNum +
(elen >> sb->s_blocksize_bits)) == start)) {
if ((0x3FFFFFFF - elen) <
@@ -435,6 +436,9 @@ static void udf_table_free_blocks(struct super_block *sb,
}
}

+ if (err < 0)
+ goto error_return;
+
if (count) {
/*
* NOTE: we CANNOT use udf_add_aext here, as it can try to
@@ -460,8 +464,6 @@ static void udf_table_free_blocks(struct super_block *sb,
else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
adsize = sizeof(struct long_ad);
else {
- brelse(oepos.bh);
- brelse(epos.bh);
goto error_return;
}

@@ -479,10 +481,10 @@ static void udf_table_free_blocks(struct super_block *sb,
__udf_add_aext(table, &epos, &eloc, elen, 1);
}

+error_return:
brelse(epos.bh);
brelse(oepos.bh);

-error_return:
mutex_unlock(&sbi->s_alloc_mutex);
return;
}
@@ -498,6 +500,7 @@ static int udf_table_prealloc_blocks(struct super_block *sb,
struct extent_position epos;
int8_t etype = -1;
struct udf_inode_info *iinfo;
+ int err = 0;

if (first_block >= sbi->s_partmaps[partition].s_partition_len)
return 0;
@@ -517,12 +520,16 @@ static int udf_table_prealloc_blocks(struct super_block *sb,
eloc.logicalBlockNum = 0xFFFFFFFF;

while (first_block != eloc.logicalBlockNum &&
- (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+ (err = udf_next_aext(table, &epos, &eloc,
+ &elen, &etype, 1)) == 1) {
udf_debug("eloc=%u, elen=%u, first_block=%u\n",
eloc.logicalBlockNum, elen, first_block);
; /* empty loop body */
}

+ if (err < 0)
+ goto err_out;
+
if (first_block == eloc.logicalBlockNum) {
epos.offset -= adsize;

@@ -539,6 +546,7 @@ static int udf_table_prealloc_blocks(struct super_block *sb,
alloc_count = 0;
}

+err_out:
brelse(epos.bh);

if (alloc_count)
@@ -560,6 +568,7 @@ static udf_pblk_t udf_table_new_block(struct super_block *sb,
struct extent_position epos, goal_epos;
int8_t etype;
struct udf_inode_info *iinfo = UDF_I(table);
+ int ret = 0;

*err = -ENOSPC;

@@ -583,8 +592,8 @@ static udf_pblk_t udf_table_new_block(struct super_block *sb,
epos.block = iinfo->i_location;
epos.bh = goal_epos.bh = NULL;

- while (spread &&
- (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+ while (spread && (ret = udf_next_aext(table, &epos, &eloc, &elen,
+ &etype, 1)) == 1) {
if (goal >= eloc.logicalBlockNum) {
if (goal < eloc.logicalBlockNum +
(elen >> sb->s_blocksize_bits))
@@ -612,7 +621,7 @@ static udf_pblk_t udf_table_new_block(struct super_block *sb,

brelse(epos.bh);

- if (spread == 0xFFFFFFFF) {
+ if (ret < 0 || spread == 0xFFFFFFFF) {
brelse(goal_epos.bh);
mutex_unlock(&sbi->s_alloc_mutex);
return 0;
diff --git a/fs/udf/directory.c b/fs/udf/directory.c
index 93153665eb37..c6950050e7ae 100644
--- a/fs/udf/directory.c
+++ b/fs/udf/directory.c
@@ -166,13 +166,19 @@ static struct buffer_head *udf_fiiter_bread_blk(struct udf_fileident_iter *iter)
*/
static int udf_fiiter_advance_blk(struct udf_fileident_iter *iter)
{
+ int8_t etype = -1;
+ int err = 0;
+
iter->loffset++;
if (iter->loffset < DIV_ROUND_UP(iter->elen, 1<<iter->dir->i_blkbits))
return 0;

iter->loffset = 0;
- if (udf_next_aext(iter->dir, &iter->epos, &iter->eloc, &iter->elen, 1)
- != (EXT_RECORDED_ALLOCATED >> 30)) {
+ err = udf_next_aext(iter->dir, &iter->epos, &iter->eloc,
+ &iter->elen, &etype, 1);
+ if (err < 0)
+ return err;
+ else if (err == 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
if (iter->pos == iter->dir->i_size) {
iter->elen = 0;
return 0;
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 70a27d2bfd29..84093f9c71c7 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -545,6 +545,7 @@ static int udf_do_extend_file(struct inode *inode,
} else {
struct kernel_lb_addr tmploc;
uint32_t tmplen;
+ int8_t tmptype;

udf_write_aext(inode, last_pos, &last_ext->extLocation,
last_ext->extLength, 1);
@@ -554,8 +555,12 @@ static int udf_do_extend_file(struct inode *inode,
* more extents, we may need to enter possible following
* empty indirect extent.
*/
- if (new_block_bytes)
- udf_next_aext(inode, last_pos, &tmploc, &tmplen, 0);
+ if (new_block_bytes) {
+ err = udf_next_aext(inode, last_pos, &tmploc, &tmplen,
+ &tmptype, 0);
+ if (err < 0)
+ goto out_err;
+ }
}
iinfo->i_lenExtents += add;

@@ -674,8 +679,10 @@ static int udf_extend_file(struct inode *inode, loff_t newsize)
extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
} else {
epos.offset -= adsize;
- etype = udf_next_aext(inode, &epos, &extent.extLocation,
- &extent.extLength, 0);
+ err = udf_next_aext(inode, &epos, &extent.extLocation,
+ &extent.extLength, &etype, 0);
+ if (err != 1)
+ goto out;
extent.extLength |= etype << 30;
}

@@ -712,11 +719,11 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
loff_t lbcount = 0, b_off = 0;
udf_pblk_t newblocknum;
sector_t offset = 0;
- int8_t etype;
+ int8_t etype, tmpetype;
struct udf_inode_info *iinfo = UDF_I(inode);
udf_pblk_t goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
int lastblock = 0;
- bool isBeyondEOF;
+ bool isBeyondEOF = false;
int ret = 0;

prev_epos.offset = udf_file_entry_alloc_offset(inode);
@@ -748,9 +755,13 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
prev_epos.offset = cur_epos.offset;
cur_epos.offset = next_epos.offset;

- etype = udf_next_aext(inode, &next_epos, &eloc, &elen, 1);
- if (etype == -1)
+ ret = udf_next_aext(inode, &next_epos, &eloc, &elen, &etype, 1);
+ if (ret < 0)
+ goto out_free;
+ else if (ret == 0) {
+ isBeyondEOF = true;
break;
+ }

c = !c;

@@ -771,13 +782,17 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
* Move prev_epos and cur_epos into indirect extent if we are at
* the pointer to it
*/
- udf_next_aext(inode, &prev_epos, &tmpeloc, &tmpelen, 0);
- udf_next_aext(inode, &cur_epos, &tmpeloc, &tmpelen, 0);
+ if (udf_next_aext(inode, &prev_epos, &tmpeloc,
+ &tmpelen, &tmpetype, 0) < 0)
+ goto out_free;
+ if (udf_next_aext(inode, &cur_epos, &tmpeloc,
+ &tmpelen, &tmpetype, 0) < 0)
+ goto out_free;

/* if the extent is allocated and recorded, return the block
if the extent is not a multiple of the blocksize, round up */

- if (etype == (EXT_RECORDED_ALLOCATED >> 30)) {
+ if (ret == 1 && etype == (EXT_RECORDED_ALLOCATED >> 30)) {
if (elen & (inode->i_sb->s_blocksize - 1)) {
elen = EXT_RECORDED_ALLOCATED |
((elen + inode->i_sb->s_blocksize - 1) &
@@ -793,10 +808,9 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
}

/* Are we beyond EOF and preallocated extent? */
- if (etype == -1) {
+ if (isBeyondEOF) {
loff_t hole_len;

- isBeyondEOF = true;
if (count) {
if (c)
laarr[0] = laarr[1];
@@ -832,7 +846,6 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)
endnum = c + 1;
lastblock = 1;
} else {
- isBeyondEOF = false;
endnum = startnum = ((count > 2) ? 2 : count);

/* if the current extent is in position 0,
@@ -846,15 +859,17 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map)

/* if the current block is located in an extent,
read the next extent */
- etype = udf_next_aext(inode, &next_epos, &eloc, &elen, 0);
- if (etype != -1) {
+ ret = udf_next_aext(inode, &next_epos, &eloc, &elen, &etype, 0);
+ if (ret == 1) {
laarr[c + 1].extLength = (etype << 30) | elen;
laarr[c + 1].extLocation = eloc;
count++;
startnum++;
endnum++;
- } else
+ } else if (ret == 0)
lastblock = 1;
+ else
+ goto out_free;
}

/* if the current extent is not recorded but allocated, get the
@@ -1172,6 +1187,7 @@ static int udf_update_extents(struct inode *inode, struct kernel_long_ad *laarr,
int start = 0, i;
struct kernel_lb_addr tmploc;
uint32_t tmplen;
+ int8_t tmpetype;
int err;

if (startnum > endnum) {
@@ -1189,14 +1205,19 @@ static int udf_update_extents(struct inode *inode, struct kernel_long_ad *laarr,
*/
if (err < 0)
return err;
- udf_next_aext(inode, epos, &laarr[i].extLocation,
- &laarr[i].extLength, 1);
+ err = udf_next_aext(inode, epos, &laarr[i].extLocation,
+ &laarr[i].extLength, &tmpetype, 1);
+ if (err < 0)
+ return err;
start++;
}
}

for (i = start; i < endnum; i++) {
- udf_next_aext(inode, epos, &tmploc, &tmplen, 0);
+ err = udf_next_aext(inode, epos, &tmploc, &tmplen, &tmpetype, 0);
+ if (err < 0)
+ return err;
+
udf_write_aext(inode, epos, &laarr[i].extLocation,
laarr[i].extLength, 1);
}
@@ -2168,16 +2189,19 @@ void udf_write_aext(struct inode *inode, struct extent_position *epos,
*/
#define UDF_MAX_INDIR_EXTS 16

-int8_t udf_next_aext(struct inode *inode, struct extent_position *epos,
- struct kernel_lb_addr *eloc, uint32_t *elen, int inc)
+/*
+ * Returns 1 on success, -errno on error, 0 on hit EOF.
+ */
+int udf_next_aext(struct inode *inode, struct extent_position *epos,
+ struct kernel_lb_addr *eloc, uint32_t *elen, int8_t *etype,
+ int inc)
{
- int8_t etype;
unsigned int indirections = 0;
int err = 0;

while ((err = udf_current_aext(inode, epos, eloc, elen,
- &etype, inc)) == 1) {
- if (etype != (EXT_NEXT_EXTENT_ALLOCDESCS >> 30))
+ etype, inc)) == 1) {
+ if (*etype != (EXT_NEXT_EXTENT_ALLOCDESCS >> 30))
break;
udf_pblk_t block;

@@ -2185,7 +2209,7 @@ int8_t udf_next_aext(struct inode *inode, struct extent_position *epos,
udf_err(inode->i_sb,
"too many indirect extents in inode %lu\n",
inode->i_ino);
- return -1;
+ return -EFSCORRUPTED;
}

epos->block = *eloc;
@@ -2195,11 +2219,11 @@ int8_t udf_next_aext(struct inode *inode, struct extent_position *epos,
epos->bh = sb_bread(inode->i_sb, block);
if (!epos->bh) {
udf_debug("reading block %u failed!\n", block);
- return -1;
+ return -EIO;
}
}

- return err == 1 ? etype : -1;
+ return err;
}

/*
@@ -2270,12 +2294,14 @@ static int udf_insert_aext(struct inode *inode, struct extent_position epos,
if (epos.bh)
get_bh(epos.bh);

- while ((etype = udf_next_aext(inode, &epos, &oeloc, &oelen, 0)) != -1) {
+ while ((err = udf_next_aext(inode, &epos, &oeloc,
+ &oelen, &etype, 0)) == 1) {
udf_write_aext(inode, &epos, &neloc, nelen, 1);
neloc = oeloc;
nelen = (etype << 30) | oelen;
}
- err = udf_add_aext(inode, &epos, &neloc, nelen, 1);
+ if (err == 0)
+ err = udf_add_aext(inode, &epos, &neloc, nelen, 1);
brelse(epos.bh);

return err;
@@ -2290,6 +2316,7 @@ int8_t udf_delete_aext(struct inode *inode, struct extent_position epos)
struct udf_inode_info *iinfo;
struct kernel_lb_addr eloc;
uint32_t elen;
+ int err = 0;

if (epos.bh) {
get_bh(epos.bh);
@@ -2305,10 +2332,11 @@ int8_t udf_delete_aext(struct inode *inode, struct extent_position epos)
adsize = 0;

oepos = epos;
- if (udf_next_aext(inode, &epos, &eloc, &elen, 1) == -1)
+ if (udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1) <= 0)
return -1;

- while ((etype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
+ while ((err = udf_next_aext(inode, &epos, &eloc,
+ &elen, &etype, 1)) == 1) {
udf_write_aext(inode, &oepos, &eloc, (etype << 30) | elen, 1);
if (oepos.bh != epos.bh) {
oepos.block = epos.block;
@@ -2318,6 +2346,11 @@ int8_t udf_delete_aext(struct inode *inode, struct extent_position epos)
oepos.offset = epos.offset - adsize;
}
}
+ if (err < 0) {
+ brelse(epos.bh);
+ brelse(oepos.bh);
+ return -1;
+ }
memset(&eloc, 0x00, sizeof(struct kernel_lb_addr));
elen = 0;

@@ -2373,6 +2406,7 @@ int8_t inode_bmap(struct inode *inode, sector_t block,
loff_t lbcount = 0, bcount = (loff_t) block << blocksize_bits;
int8_t etype;
struct udf_inode_info *iinfo;
+ int err = 0;

iinfo = UDF_I(inode);
if (!udf_read_extent_cache(inode, bcount, &lbcount, pos)) {
@@ -2382,10 +2416,12 @@ int8_t inode_bmap(struct inode *inode, sector_t block,
}
*elen = 0;
do {
- etype = udf_next_aext(inode, pos, eloc, elen, 1);
- if (etype == -1) {
- *offset = (bcount - lbcount) >> blocksize_bits;
- iinfo->i_lenExtents = lbcount;
+ err = udf_next_aext(inode, pos, eloc, elen, &etype, 1);
+ if (err <= 0) {
+ if (err == 0) {
+ *offset = (bcount - lbcount) >> blocksize_bits;
+ iinfo->i_lenExtents = lbcount;
+ }
return -1;
}
lbcount += *elen;
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 3460ecc826d1..4bb7f600b99f 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -2482,13 +2482,14 @@ static unsigned int udf_count_free_table(struct super_block *sb,
uint32_t elen;
struct kernel_lb_addr eloc;
struct extent_position epos;
+ int8_t etype;

mutex_lock(&UDF_SB(sb)->s_alloc_mutex);
epos.block = UDF_I(table)->i_location;
epos.offset = sizeof(struct unallocSpaceEntry);
epos.bh = NULL;

- while (udf_next_aext(table, &epos, &eloc, &elen, 1) != -1)
+ while (udf_next_aext(table, &epos, &eloc, &elen, &etype, 1) == 1)
accum += (elen >> table->i_sb->s_blocksize_bits);

brelse(epos.bh);
diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
index 76186b211efe..b91876a7b53a 100644
--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -69,6 +69,7 @@ void udf_truncate_tail_extent(struct inode *inode)
int8_t etype = -1, netype;
int adsize;
struct udf_inode_info *iinfo = UDF_I(inode);
+ int err = 0;

if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
inode->i_size == iinfo->i_lenExtents)
@@ -85,7 +86,8 @@ void udf_truncate_tail_extent(struct inode *inode)
BUG();

/* Find the last extent in the file */
- while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
+ while ((err = udf_next_aext(inode, &epos, &eloc,
+ &elen, &netype, 1)) == 1) {
etype = netype;
lbcount += elen;
if (lbcount > inode->i_size) {
@@ -101,7 +103,8 @@ void udf_truncate_tail_extent(struct inode *inode)
epos.offset -= adsize;
extent_trunc(inode, &epos, &eloc, etype, elen, nelen);
epos.offset += adsize;
- if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
+ if (udf_next_aext(inode, &epos, &eloc, &elen,
+ &netype, 1) == 1)
udf_err(inode->i_sb,
"Extent after EOF in inode %u\n",
(unsigned)inode->i_ino);
@@ -110,7 +113,8 @@ void udf_truncate_tail_extent(struct inode *inode)
}
/* This inode entry is in-memory only and thus we don't have to mark
* the inode dirty */
- iinfo->i_lenExtents = inode->i_size;
+ if (err == 0)
+ iinfo->i_lenExtents = inode->i_size;
brelse(epos.bh);
}

@@ -124,6 +128,8 @@ void udf_discard_prealloc(struct inode *inode)
int8_t etype = -1;
struct udf_inode_info *iinfo = UDF_I(inode);
int bsize = i_blocksize(inode);
+ int8_t tmpetype = -1;
+ int err = 0;

if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
@@ -132,16 +138,22 @@ void udf_discard_prealloc(struct inode *inode)
epos.block = iinfo->i_location;

/* Find the last extent in the file */
- while (udf_next_aext(inode, &epos, &eloc, &elen, 0) != -1) {
+ while ((err = udf_next_aext(inode, &epos, &eloc,
+ &elen, &tmpetype, 0)) == 1) {
brelse(prev_epos.bh);
prev_epos = epos;
if (prev_epos.bh)
get_bh(prev_epos.bh);

- etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
+ err = udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1);
+ if (err <= 0)
+ break;
lbcount += elen;
}
- if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
+ if (err < 0)
+ goto out;
+
+ if (err == 1 && etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
lbcount -= elen;
udf_delete_aext(inode, prev_epos);
udf_free_blocks(inode->i_sb, inode, &eloc, 0,
@@ -150,6 +162,7 @@ void udf_discard_prealloc(struct inode *inode)
/* This inode entry is in-memory only and thus we don't have to mark
* the inode dirty */
iinfo->i_lenExtents = lbcount;
+out:
brelse(epos.bh);
brelse(prev_epos.bh);
}
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index d893db95ac70..5067ed68a8b4 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -169,8 +169,9 @@ extern int udf_add_aext(struct inode *, struct extent_position *,
extern void udf_write_aext(struct inode *, struct extent_position *,
struct kernel_lb_addr *, uint32_t, int);
extern int8_t udf_delete_aext(struct inode *, struct extent_position);
-extern int8_t udf_next_aext(struct inode *, struct extent_position *,
- struct kernel_lb_addr *, uint32_t *, int);
+extern int udf_next_aext(struct inode *inode, struct extent_position *epos,
+ struct kernel_lb_addr *eloc, uint32_t *elen,
+ int8_t *etype, int inc);
extern int udf_current_aext(struct inode *inode, struct extent_position *epos,
struct kernel_lb_addr *eloc, uint32_t *elen,
int8_t *etype, int inc);
--
2.43.0