udf: Move handling of uniqueID into a helper function and protect it by a s_alloc_mutex

uniqueID handling has been duplicated in three places. Move it into a common
helper. Since we modify an LVID buffer with uniqueID update, we take
sbi->s_alloc_mutex to protect agaist other modifications of the structure.

Signed-off-by: Jan Kara <jack@suse.cz>

4 files changed, 47 insertions, 53 deletions

diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c
index 75d9304d0dc3..6fb7e0adcda0 100644
--- a/fs/udf/ialloc.c
+++ b/fs/udf/ialloc.c
@@ -92,28 +92,19 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err)
                 return NULL;
         }
 
-        mutex_lock(&sbi->s_alloc_mutex);
         if (sbi->s_lvid_bh) {
-                struct logicalVolIntegrityDesc *lvid =
-                        (struct logicalVolIntegrityDesc *)
-                        sbi->s_lvid_bh->b_data;
-                struct logicalVolIntegrityDescImpUse *lvidiu =
-                                                        udf_sb_lvidiu(sbi);
-                struct logicalVolHeaderDesc *lvhd;
-                uint64_t uniqueID;
-                lvhd = (struct logicalVolHeaderDesc *)
-                                (lvid->logicalVolContentsUse);
+                struct logicalVolIntegrityDescImpUse *lvidiu;
+
+                iinfo->i_unique = lvid_get_unique_id(sb);
+                mutex_lock(&sbi->s_alloc_mutex);
+                lvidiu = udf_sb_lvidiu(sbi);
                 if (S_ISDIR(mode))
                         le32_add_cpu(&lvidiu->numDirs, 1);
                 else
                         le32_add_cpu(&lvidiu->numFiles, 1);
-                iinfo->i_unique = uniqueID = le64_to_cpu(lvhd->uniqueID);
-                if (!(++uniqueID & 0x00000000FFFFFFFFUL))
-                        uniqueID += 16;
-                lvhd->uniqueID = cpu_to_le64(uniqueID);
                 udf_updated_lvid(sb);
+                mutex_unlock(&sbi->s_alloc_mutex);
         }
-        mutex_unlock(&sbi->s_alloc_mutex);
 
         inode_init_owner(inode, dir, mode);
 
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 6d8dc02baebb..701fcda18415 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -890,8 +890,8 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
         int block;
         unsigned char *name = NULL;
         int namelen;
-        struct buffer_head *bh;
         struct udf_inode_info *iinfo;
+        struct super_block *sb = dir->i_sb;
 
         lock_kernel();
         inode = udf_new_inode(dir, S_IFLNK | S_IRWXUGO, &err);
@@ -912,7 +912,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
                 struct kernel_lb_addr eloc;
                 uint32_t bsize;
 
-                block = udf_new_block(inode->i_sb, inode,
+                block = udf_new_block(sb, inode,
                                 iinfo->i_location.partitionReferenceNum,
                                 iinfo->i_location.logicalBlockNum, &err);
                 if (!block)
@@ -923,17 +923,17 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
                 eloc.logicalBlockNum = block;
                 eloc.partitionReferenceNum =
                                 iinfo->i_location.partitionReferenceNum;
-                bsize = inode->i_sb->s_blocksize;
+                bsize = sb->s_blocksize;
                 iinfo->i_lenExtents = bsize;
                 udf_add_aext(inode, &epos, &eloc, bsize, 0);
                 brelse(epos.bh);
 
-                block = udf_get_pblock(inode->i_sb, block,
+                block = udf_get_pblock(sb, block,
                                 iinfo->i_location.partitionReferenceNum,
                                 0);
-                epos.bh = udf_tgetblk(inode->i_sb, block);
+                epos.bh = udf_tgetblk(sb, block);
                 lock_buffer(epos.bh);
-                memset(epos.bh->b_data, 0x00, inode->i_sb->s_blocksize);
+                memset(epos.bh->b_data, 0x00, bsize);
                 set_buffer_uptodate(epos.bh);
                 unlock_buffer(epos.bh);
                 mark_buffer_dirty_inode(epos.bh, inode);
@@ -941,7 +941,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
         } else
                 ea = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
 
-        eoffset = inode->i_sb->s_blocksize - udf_ext0_offset(inode);
+        eoffset = sb->s_blocksize - udf_ext0_offset(inode);
         pc = (struct pathComponent *)ea;
 
         if (*symname == '/') {
@@ -981,7 +981,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
                 }
 
                 if (pc->componentType == 5) {
-                        namelen = udf_put_filename(inode->i_sb, compstart, name,
+                        namelen = udf_put_filename(sb, compstart, name,
                                                    symname - compstart);
                         if (!namelen)
                                 goto out_no_entry;
@@ -1015,23 +1015,11 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
         fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err);
         if (!fi)
                 goto out_no_entry;
-        cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
+        cfi.icb.extLength = cpu_to_le32(sb->s_blocksize);
         cfi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
-        bh = UDF_SB(inode->i_sb)->s_lvid_bh;
-        if (bh) {
-                struct logicalVolIntegrityDesc *lvid =
-                                (struct logicalVolIntegrityDesc *)bh->b_data;
-                struct logicalVolHeaderDesc *lvhd;
-                uint64_t uniqueID;
-                lvhd = (struct logicalVolHeaderDesc *)
-                                lvid->logicalVolContentsUse;
-                uniqueID = le64_to_cpu(lvhd->uniqueID);
+        if (UDF_SB(inode->i_sb)->s_lvid_bh) {
                 *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
-                        cpu_to_le32(uniqueID & 0x00000000FFFFFFFFUL);
-                if (!(++uniqueID & 0x00000000FFFFFFFFUL))
-                        uniqueID += 16;
-                lvhd->uniqueID = cpu_to_le64(uniqueID);
-                mark_buffer_dirty(bh);
+                        cpu_to_le32(lvid_get_unique_id(sb));
         }
         udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
         if (UDF_I(dir)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
@@ -1060,7 +1048,6 @@ static int udf_link(struct dentry *old_dentry, struct inode *dir,
         struct udf_fileident_bh fibh;
         struct fileIdentDesc cfi, *fi;
         int err;
-        struct buffer_head *bh;
 
         lock_kernel();
         if (inode->i_nlink >= (256 << sizeof(inode->i_nlink)) - 1) {
@@ -1075,21 +1062,9 @@ static int udf_link(struct dentry *old_dentry, struct inode *dir,
         }
         cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
         cfi.icb.extLocation = cpu_to_lelb(UDF_I(inode)->i_location);
-        bh = UDF_SB(inode->i_sb)->s_lvid_bh;
-        if (bh) {
-                struct logicalVolIntegrityDesc *lvid =
-                                (struct logicalVolIntegrityDesc *)bh->b_data;
-                struct logicalVolHeaderDesc *lvhd;
-                uint64_t uniqueID;
-                lvhd = (struct logicalVolHeaderDesc *)
-                                (lvid->logicalVolContentsUse);
-                uniqueID = le64_to_cpu(lvhd->uniqueID);
+        if (UDF_SB(inode->i_sb)->s_lvid_bh) {
                 *(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
-                        cpu_to_le32(uniqueID & 0x00000000FFFFFFFFUL);
-                if (!(++uniqueID & 0x00000000FFFFFFFFUL))
-                        uniqueID += 16;
-                lvhd->uniqueID = cpu_to_le64(uniqueID);
-                mark_buffer_dirty(bh);
+                        cpu_to_le32(lvid_get_unique_id(inode->i_sb));
         }
         udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
         if (UDF_I(dir)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
diff --git a/fs/udf/super.c b/fs/udf/super.c
index f99ff5dbd741..948e1aca0f34 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1823,6 +1823,33 @@ static void udf_close_lvid(struct super_block *sb)
         sbi->s_lvid_dirty = 0;
 }
 
+u64 lvid_get_unique_id(struct super_block *sb)
+{
+        struct buffer_head *bh;
+        struct udf_sb_info *sbi = UDF_SB(sb);
+        struct logicalVolIntegrityDesc *lvid;
+        struct logicalVolHeaderDesc *lvhd;
+        u64 uniqueID;
+        u64 ret;
+
+        bh = sbi->s_lvid_bh;
+        if (!bh)
+                return 0;
+
+        lvid = (struct logicalVolIntegrityDesc *)bh->b_data;
+        lvhd = (struct logicalVolHeaderDesc *)lvid->logicalVolContentsUse;
+
+        mutex_lock(&sbi->s_alloc_mutex);
+        ret = uniqueID = le64_to_cpu(lvhd->uniqueID);
+        if (!(++uniqueID & 0xFFFFFFFF))
+                uniqueID += 16;
+        lvhd->uniqueID = cpu_to_le64(uniqueID);
+        mutex_unlock(&sbi->s_alloc_mutex);
+        mark_buffer_dirty(bh);
+
+        return ret;
+}
+
 static void udf_sb_free_bitmap(struct udf_bitmap *bitmap)
 {
         int i;
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index f25e57e8a777..eba48209f9f3 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -125,6 +125,7 @@ static inline void udf_updated_lvid(struct super_block *sb)
         sb->s_dirt = 1;
         UDF_SB(sb)->s_lvid_dirty = 1;
 }
+extern u64 lvid_get_unique_id(struct super_block *sb);
 
 /* namei.c */
 extern int udf_write_fi(struct inode *inode, struct fileIdentDesc *,