ext4: modify ext4_xattr_ino_array to hold struct inode *

Tracking struct inode * rather than the inode number eliminates the
repeated ext4_xattr_inode_iget() call later. The second call cannot
fail in practice but still requires explanation when it wants to ignore
the return value. Avoid the trouble and make things simple.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

4 files changed, 53 insertions, 59 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9b6a10e1bf18..144a2863ba27 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2243,9 +2243,9 @@ struct mmpd_data {
 # define ATTRIB_NORET   __attribute__((noreturn))
 # define NORET_AND      noreturn,
 
-struct ext4_xattr_ino_array {
-        unsigned int xia_count;         /* # of used item in the array */
-        unsigned int xia_inodes[0];
+struct ext4_xattr_inode_array {
+        unsigned int count;             /* # of used items in the array */
+        struct inode *inodes[0];
 };
 /* bitmap.c */
 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index fda70fedf56d..1b2a68c5ea42 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -188,7 +188,7 @@ void ext4_evict_inode(struct inode *inode)
         handle_t *handle;
         int err;
         int extra_credits = 3;
-        struct ext4_xattr_ino_array *lea_ino_array = NULL;
+        struct ext4_xattr_inode_array *ea_inode_array = NULL;
 
         trace_ext4_evict_inode(inode);
 
@@ -257,7 +257,7 @@ void ext4_evict_inode(struct inode *inode)
         /*
          * Delete xattr inode before deleting the main inode.
          */
-        err = ext4_xattr_delete_inode(handle, inode, &lea_ino_array);
+        err = ext4_xattr_delete_inode(handle, inode, &ea_inode_array);
         if (err) {
                 ext4_warning(inode->i_sb,
                              "couldn't delete inode's xattr (err %d)", err);
@@ -345,9 +345,7 @@ void ext4_evict_inode(struct inode *inode)
 
         ext4_journal_stop(handle);
         sb_end_intwrite(inode->i_sb);
-
-        if (lea_ino_array != NULL)
-                ext4_xattr_inode_array_free(inode, lea_ino_array);
+        ext4_xattr_inode_array_free(ea_inode_array);
         return;
 no_delete:
         ext4_clear_inode(inode);        /* We must guarantee clearing of inode... */
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 43a2c075aa1f..fed54001c9e6 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1940,44 +1940,44 @@ cleanup:
 
 #define EIA_INCR 16 /* must be 2^n */
 #define EIA_MASK (EIA_INCR - 1)
-/* Add the large xattr @ino into @lea_ino_array for later deletion.
- * If @lea_ino_array is new or full it will be grown and the old
+/* Add the large xattr @inode into @ea_inode_array for later deletion.
+ * If @ea_inode_array is new or full it will be grown and the old
  * contents copied over.
  */
 static int
-ext4_expand_ino_array(struct ext4_xattr_ino_array **lea_ino_array, __u32 ino)
+ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
+                        struct inode *inode)
 {
-        if (*lea_ino_array == NULL) {
+        if (*ea_inode_array == NULL) {
                 /*
                  * Start with 15 inodes, so it fits into a power-of-two size.
-                 * If *lea_ino_array is NULL, this is essentially offsetof()
+                 * If *ea_inode_array is NULL, this is essentially offsetof()
                  */
-                (*lea_ino_array) =
-                        kmalloc(offsetof(struct ext4_xattr_ino_array,
-                                         xia_inodes[EIA_MASK]),
+                (*ea_inode_array) =
+                        kmalloc(offsetof(struct ext4_xattr_inode_array,
+                                         inodes[EIA_MASK]),
                                 GFP_NOFS);
-                if (*lea_ino_array == NULL)
+                if (*ea_inode_array == NULL)
                         return -ENOMEM;
-                (*lea_ino_array)->xia_count = 0;
-        } else if (((*lea_ino_array)->xia_count & EIA_MASK) == EIA_MASK) {
+                (*ea_inode_array)->count = 0;
+        } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
                 /* expand the array once all 15 + n * 16 slots are full */
-                struct ext4_xattr_ino_array *new_array = NULL;
-                int count = (*lea_ino_array)->xia_count;
+                struct ext4_xattr_inode_array *new_array = NULL;
+                int count = (*ea_inode_array)->count;
 
                 /* if new_array is NULL, this is essentially offsetof() */
                 new_array = kmalloc(
-                                offsetof(struct ext4_xattr_ino_array,
-                                         xia_inodes[count + EIA_INCR]),
+                                offsetof(struct ext4_xattr_inode_array,
+                                         inodes[count + EIA_INCR]),
                                 GFP_NOFS);
                 if (new_array == NULL)
                         return -ENOMEM;
-                memcpy(new_array, *lea_ino_array,
-                       offsetof(struct ext4_xattr_ino_array,
-                                xia_inodes[count]));
-                kfree(*lea_ino_array);
-                *lea_ino_array = new_array;
+                memcpy(new_array, *ea_inode_array,
+                       offsetof(struct ext4_xattr_inode_array, inodes[count]));
+                kfree(*ea_inode_array);
+                *ea_inode_array = new_array;
         }
-        (*lea_ino_array)->xia_inodes[(*lea_ino_array)->xia_count++] = ino;
+        (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
         return 0;
 }
 
@@ -1985,16 +1985,16 @@ ext4_expand_ino_array(struct ext4_xattr_ino_array **lea_ino_array, __u32 ino)
  * Add xattr inode to orphan list
  */
 static int
-ext4_xattr_inode_orphan_add(handle_t *handle, struct inode *inode,
-                        int credits, struct ext4_xattr_ino_array *lea_ino_array)
+ext4_xattr_inode_orphan_add(handle_t *handle, struct inode *inode, int credits,
+                            struct ext4_xattr_inode_array *ea_inode_array)
 {
-        struct inode *ea_inode;
         int idx = 0, error = 0;
+        struct inode *ea_inode;
 
-        if (lea_ino_array == NULL)
+        if (ea_inode_array == NULL)
                 return 0;
 
-        for (; idx < lea_ino_array->xia_count; ++idx) {
+        for (; idx < ea_inode_array->count; ++idx) {
                 if (!ext4_handle_has_enough_credits(handle, credits)) {
                         error = ext4_journal_extend(handle, credits);
                         if (error > 0)
@@ -2007,10 +2007,7 @@ ext4_xattr_inode_orphan_add(handle_t *handle, struct inode *inode,
                                 return error;
                         }
                 }
-                error = ext4_xattr_inode_iget(inode,
-                                lea_ino_array->xia_inodes[idx], &ea_inode);
-                if (error)
-                        continue;
+                ea_inode = ea_inode_array->inodes[idx];
                 inode_lock(ea_inode);
                 ext4_orphan_add(handle, ea_inode);
                 inode_unlock(ea_inode);
@@ -2032,13 +2029,14 @@ ext4_xattr_inode_orphan_add(handle_t *handle, struct inode *inode,
  */
 int
 ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
-                        struct ext4_xattr_ino_array **lea_ino_array)
+                        struct ext4_xattr_inode_array **ea_inode_array)
 {
         struct buffer_head *bh = NULL;
         struct ext4_xattr_ibody_header *header;
         struct ext4_inode *raw_inode;
         struct ext4_iloc iloc;
         struct ext4_xattr_entry *entry;
+        struct inode *ea_inode;
         unsigned int ea_ino;
         int credits = 3, error = 0;
 
@@ -2055,8 +2053,12 @@ ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
                 if (!entry->e_value_inum)
                         continue;
                 ea_ino = le32_to_cpu(entry->e_value_inum);
-                error = ext4_expand_ino_array(lea_ino_array, ea_ino);
+                error = ext4_xattr_inode_iget(inode, ea_ino, &ea_inode);
+                if (error)
+                        continue;
+                error = ext4_expand_inode_array(ea_inode_array, ea_inode);
                 if (error) {
+                        iput(ea_inode);
                         brelse(iloc.bh);
                         goto cleanup;
                 }
@@ -2068,7 +2070,7 @@ delete_external_ea:
         if (!EXT4_I(inode)->i_file_acl) {
                 /* add xattr inode to orphan list */
                 error = ext4_xattr_inode_orphan_add(handle, inode, credits,
-                                                    *lea_ino_array);
+                                                    *ea_inode_array);
                 goto cleanup;
         }
         bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
@@ -2091,7 +2093,10 @@ delete_external_ea:
                 if (!entry->e_value_inum)
                         continue;
                 ea_ino = le32_to_cpu(entry->e_value_inum);
-                error = ext4_expand_ino_array(lea_ino_array, ea_ino);
+                error = ext4_xattr_inode_iget(inode, ea_ino, &ea_inode);
+                if (error)
+                        continue;
+                error = ext4_expand_inode_array(ea_inode_array, ea_inode);
                 if (error)
                         goto cleanup;
                 entry->e_value_inum = 0;
@@ -2099,7 +2104,7 @@ delete_external_ea:
 
         /* add xattr inode to orphan list */
         error = ext4_xattr_inode_orphan_add(handle, inode, credits,
-                                        *lea_ino_array);
+                                        *ea_inode_array);
         if (error)
                 goto cleanup;
 
@@ -2126,28 +2131,20 @@ cleanup:
         return error;
 }
 
-void
-ext4_xattr_inode_array_free(struct inode *inode,
-                            struct ext4_xattr_ino_array *lea_ino_array)
+void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
 {
         struct inode    *ea_inode;
         int             idx = 0;
-        int             err;
 
-        if (lea_ino_array == NULL)
+        if (ea_inode_array == NULL)
                 return;
 
-        for (; idx < lea_ino_array->xia_count; ++idx) {
-                err = ext4_xattr_inode_iget(inode,
-                                lea_ino_array->xia_inodes[idx], &ea_inode);
-                if (err)
-                        continue;
-                /* for inode's i_count get from ext4_xattr_delete_inode */
-                iput(ea_inode);
+        for (; idx < ea_inode_array->count; ++idx) {
+                ea_inode = ea_inode_array->inodes[idx];
                 clear_nlink(ea_inode);
                 iput(ea_inode);
         }
-        kfree(lea_ino_array);
+        kfree(ea_inode_array);
 }
 
 /*
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index e82c5fe36a26..323eba54f72f 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -164,9 +164,8 @@ extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len);
 
 extern int ext4_xattr_inode_unlink(struct inode *inode, unsigned long ea_ino);
 extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
-                                   struct ext4_xattr_ino_array **array);
-extern void ext4_xattr_inode_array_free(struct inode *inode,
-                                        struct ext4_xattr_ino_array *array);
+                                   struct ext4_xattr_inode_array **array);
+extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array);
 
 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
                             struct ext4_inode *raw_inode, handle_t *handle);