ext4: improve journal credit handling in set xattr paths

Both ext4_set_acl() and ext4_set_context() need to be made aware of
ea_inode feature when it comes to credits calculation.

Also add a sufficient credits check in ext4_xattr_set_handle() right
after xattr write lock is grabbed. Original credits calculation is done
outside the lock so there is a possiblity that the initially calculated
credits are not sufficient anymore.

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

diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index 3ec0e46de95fc8dece943c4d753eb401e6343cad..74f7ac539e00ce877d34e7121b818cace1455258 100644 (file)
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -231,14 +231,15 @@ int
 ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
        handle_t *handle;
-       int error, retries = 0;
+       int error, credits, retries = 0;
+       size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
 
        error = dquot_initialize(inode);
        if (error)
                return error;
 retry:
-       handle = ext4_journal_start(inode, EXT4_HT_XATTR,
-                                   ext4_jbd2_credits_xattr(inode));
+       credits = ext4_xattr_set_credits(inode, acl_size);
+       handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
        if (IS_ERR(handle))
                return PTR_ERR(handle);
 

diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 5e61e464d71c7e01b7f86ac97d4fca35a0516a4b..dabad1bc861723932fd7f25da1d86cdd0a641ce9 100644 (file)
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -111,20 +111,6 @@
 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
 
-static inline int ext4_jbd2_credits_xattr(struct inode *inode)
-{
-       int credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
-
-       /*
-        * In case of inline data, we may push out the data to a block,
-        * so we need to reserve credits for this eventuality
-        */
-       if (ext4_has_inline_data(inode))
-               credits += ext4_writepage_trans_blocks(inode) + 1;
-       return credits;
-}
-
-
 /*
  * Ext4 handle operation types -- for logging purposes
  */

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d37c81f327e790cc4a309fd0a12baef0dc2ff4ac..b02a23ec92ca058ce5cefb72c7ce30e832fe4b2a 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1143,7 +1143,7 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
                                                        void *fs_data)
 {
        handle_t *handle = fs_data;
-       int res, res2, retries = 0;
+       int res, res2, credits, retries = 0;
 
        res = ext4_convert_inline_data(inode);
        if (res)
@@ -1178,8 +1178,8 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
        if (res)
                return res;
 retry:
-       handle = ext4_journal_start(inode, EXT4_HT_MISC,
-                       ext4_jbd2_credits_xattr(inode));
+       credits = ext4_xattr_set_credits(inode, len);
+       handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
        if (IS_ERR(handle))
                return PTR_ERR(handle);
 

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index c8b71bd118b06080c2a50a783ae4d682c9156ab3..43a2c075aa1f2e1ea5d1b38ee2cec3c670d2efc2 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1471,6 +1471,17 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 
        ext4_write_lock_xattr(inode, &no_expand);
 
+       /* Check journal credits under write lock. */
+       if (ext4_handle_valid(handle)) {
+               int credits;
+
+               credits = ext4_xattr_set_credits(inode, value_len);
+               if (!ext4_handle_has_enough_credits(handle, credits)) {
+                       error = -ENOSPC;
+                       goto cleanup;
+               }
+       }
+
        error = ext4_reserve_inode_write(handle, inode, &is.iloc);
        if (error)
                goto cleanup;
@@ -1568,6 +1579,36 @@ cleanup:
        return error;
 }
 
+int ext4_xattr_set_credits(struct inode *inode, size_t value_len)
+{
+       struct super_block *sb = inode->i_sb;
+       int credits;
+
+       if (!EXT4_SB(sb)->s_journal)
+               return 0;
+
+       credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
+
+       /*
+        * In case of inline data, we may push out the data to a block,
+        * so we need to reserve credits for this eventuality
+        */
+       if (ext4_has_inline_data(inode))
+               credits += ext4_writepage_trans_blocks(inode) + 1;
+
+       if (ext4_has_feature_ea_inode(sb)) {
+               int nrblocks = (value_len + sb->s_blocksize - 1) >>
+                                       sb->s_blocksize_bits;
+
+               /* For new inode */
+               credits += EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + 3;
+
+               /* For data blocks of EA inode */
+               credits += ext4_meta_trans_blocks(inode, nrblocks, 0);
+       }
+       return credits;
+}
+
 /*
  * ext4_xattr_set()
  *
@@ -1583,24 +1624,14 @@ ext4_xattr_set(struct inode *inode, int name_index, const char *name,
        handle_t *handle;
        struct super_block *sb = inode->i_sb;
        int error, retries = 0;
-       int credits = ext4_jbd2_credits_xattr(inode);
+       int credits;
 
        error = dquot_initialize(inode);
        if (error)
                return error;
 
-       if (ext4_has_feature_ea_inode(sb)) {
-               int nrblocks = (value_len + sb->s_blocksize - 1) >>
-                                       sb->s_blocksize_bits;
-
-               /* For new inode */
-               credits += EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + 3;
-
-               /* For data blocks of EA inode */
-               credits += ext4_meta_trans_blocks(inode, nrblocks, 0);
-       }
-
 retry:
+       credits = ext4_xattr_set_credits(inode, value_len);
        handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
        if (IS_ERR(handle)) {
                error = PTR_ERR(handle);

diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index b6ef99d1a061fe020ca0c7a59b6475667b05c84b..e82c5fe36a26958aef74367131e9a79ca11e5acb 100644 (file)
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -160,6 +160,7 @@ extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
+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,