dquot: Detect partial write error to quota file in write_blk() and add printk_ratelim...

This patch changes quota_tree.c:write_blk() to detect error caused by partial
write to quota file and add a macro to limit control printed quota error
messages so we won't fill up dmesg with a corrupted quota file.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index 5b7f741..24f0340 100644 (file)
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -60,9 +60,17 @@ static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
 static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
 {
        struct super_block *sb = info->dqi_sb;
+       ssize_t ret;
 
-       return sb->s_op->quota_write(sb, info->dqi_type, buf,
+       ret = sb->s_op->quota_write(sb, info->dqi_type, buf,
               info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
+       if (ret != info->dqi_usable_bs) {
+               q_warn(KERN_WARNING "VFS: dquota write failed on "
+                       "dev %s\n", sb->s_id);
+               if (ret >= 0)
+                       ret = -EIO;
+       }
+       return ret;
 }
 
 /* Remove empty block from list and return it */
@@ -152,7 +160,7 @@ static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
        dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
        /* No matter whether write succeeds block is out of list */
        if (write_blk(info, blk, buf) < 0)
-               printk(KERN_ERR
+               q_warn(KERN_ERR
                       "VFS: Can't write block (%u) with free entries.\n",
                       blk);
        return 0;
@@ -244,7 +252,7 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
        if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
                *err = remove_free_dqentry(info, buf, blk);
                if (*err < 0) {
-                       printk(KERN_ERR "VFS: find_free_dqentry(): Can't "
+                       q_warn(KERN_ERR "VFS: find_free_dqentry(): Can't "
                               "remove block (%u) from entry free list.\n",
                               blk);
                        goto out_buf;
@@ -268,7 +276,7 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
 #endif
        *err = write_blk(info, blk, buf);
        if (*err < 0) {
-               printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota "
+               q_warn(KERN_ERR "VFS: find_free_dqentry(): Can't write quota "
                                "data block %u.\n", blk);
                goto out_buf;
        }
@@ -303,7 +311,7 @@ static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
        } else {
                ret = read_blk(info, *treeblk, buf);
                if (ret < 0) {
-                       printk(KERN_ERR "VFS: Can't read tree quota block "
+                       q_warn(KERN_ERR "VFS: Can't read tree quota block "
                                        "%u.\n", *treeblk);
                        goto out_buf;
                }
@@ -365,7 +373,7 @@ int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
        if (!dquot->dq_off) {
                ret = dq_insert_tree(info, dquot);
                if (ret < 0) {
-                       printk(KERN_ERR "VFS: Error %zd occurred while "
+                       q_warn(KERN_ERR "VFS: Error %zd occurred while "
                                        "creating quota.\n", ret);
                        kfree(ddquot);
                        return ret;
@@ -377,7 +385,7 @@ int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
        ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
                                    dquot->dq_off);
        if (ret != info->dqi_entry_size) {
-               printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
+               q_warn(KERN_WARNING "VFS: dquota write failed on dev %s\n",
                       sb->s_id);
                if (ret >= 0)
                        ret = -ENOSPC;
@@ -402,14 +410,14 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
        if (!buf)
                return -ENOMEM;
        if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
-               printk(KERN_ERR "VFS: Quota structure has offset to other "
+               q_warn(KERN_ERR "VFS: Quota structure has offset to other "
                  "block (%u) than it should (%u).\n", blk,
                  (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
                goto out_buf;
        }
        ret = read_blk(info, blk, buf);
        if (ret < 0) {
-               printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
+               q_warn(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
                goto out_buf;
        }
        dh = (struct qt_disk_dqdbheader *)buf;
@@ -419,7 +427,7 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
                if (ret >= 0)
                        ret = put_free_dqblk(info, buf, blk);
                if (ret < 0) {
-                       printk(KERN_ERR "VFS: Can't move quota data block (%u) "
+                       q_warn(KERN_ERR "VFS: Can't move quota data block (%u) "
                          "to free list.\n", blk);
                        goto out_buf;
                }
@@ -432,14 +440,14 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
                        /* Insert will write block itself */
                        ret = insert_free_dqentry(info, buf, blk);
                        if (ret < 0) {
-                               printk(KERN_ERR "VFS: Can't insert quota data "
+                               q_warn(KERN_ERR "VFS: Can't insert quota data "
                                       "block (%u) to free entry list.\n", blk);
                                goto out_buf;
                        }
                } else {
                        ret = write_blk(info, blk, buf);
                        if (ret < 0) {
-                               printk(KERN_ERR "VFS: Can't write quota data "
+                               q_warn(KERN_ERR "VFS: Can't write quota data "
                                  "block %u\n", blk);
                                goto out_buf;
                        }
@@ -464,7 +472,7 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
                return -ENOMEM;
        ret = read_blk(info, *blk, buf);
        if (ret < 0) {
-               printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
+               q_warn(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
                goto out_buf;
        }
        newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
@@ -488,7 +496,7 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
                } else {
                        ret = write_blk(info, *blk, buf);
                        if (ret < 0)
-                               printk(KERN_ERR "VFS: Can't write quota tree "
+                               q_warn(KERN_ERR "VFS: Can't write quota tree "
                                  "block %u.\n", *blk);
                }
        }
@@ -521,7 +529,7 @@ static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
                return -ENOMEM;
        ret = read_blk(info, blk, buf);
        if (ret < 0) {
-               printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
+               q_warn(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
                goto out_buf;
        }
        ddquot = buf + sizeof(struct qt_disk_dqdbheader);
@@ -531,7 +539,7 @@ static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
                ddquot += info->dqi_entry_size;
        }
        if (i == qtree_dqstr_in_blk(info)) {
-               printk(KERN_ERR "VFS: Quota for id %u referenced "
+               q_warn(KERN_ERR "VFS: Quota for id %u referenced "
                  "but not present.\n", dquot->dq_id);
                ret = -EIO;
                goto out_buf;
@@ -556,7 +564,7 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
                return -ENOMEM;
        ret = read_blk(info, blk, buf);
        if (ret < 0) {
-               printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
+               q_warn(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
                goto out_buf;
        }
        ret = 0;
@@ -599,7 +607,7 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
                offset = find_dqentry(info, dquot);
                if (offset <= 0) {      /* Entry not present? */
                        if (offset < 0)
-                               printk(KERN_ERR "VFS: Can't read quota "
+                               q_warn(KERN_ERR "VFS: Can't read quota "
                                  "structure for id %u.\n", dquot->dq_id);
                        dquot->dq_off = 0;
                        set_bit(DQ_FAKE_B, &dquot->dq_flags);
@@ -617,7 +625,7 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
        if (ret != info->dqi_entry_size) {
                if (ret >= 0)
                        ret = -EIO;
-               printk(KERN_ERR "VFS: Error while reading quota "
+               q_warn(KERN_ERR "VFS: Error while reading quota "
                                "structure for id %u.\n", dquot->dq_id);
                set_bit(DQ_FAKE_B, &dquot->dq_flags);
                memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));

diff --git a/fs/quota/quota_tree.h b/fs/quota/quota_tree.h
index a1ab8db..ccc3e71 100644 (file)
--- a/fs/quota/quota_tree.h
+++ b/fs/quota/quota_tree.h
@@ -22,4 +22,10 @@ struct qt_disk_dqdbheader {
 
 #define QT_TREEOFF     1               /* Offset of tree in file in blocks */
 
+#define q_warn(fmt, args...) \
+do { \
+       if (printk_ratelimit()) \
+               printk(fmt, ## args); \
+} while(0)
+
 #endif /* _LINUX_QUOTAIO_TREE_H */

diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
index e3da02f..135206a 100644 (file)
--- a/fs/quota/quota_v2.c
+++ b/fs/quota/quota_v2.c
@@ -63,7 +63,7 @@ static int v2_read_header(struct super_block *sb, int type,
        size = sb->s_op->quota_read(sb, type, (char *)dqhead,
                                    sizeof(struct v2_disk_dqheader), 0);
        if (size != sizeof(struct v2_disk_dqheader)) {
-               printk(KERN_WARNING "quota_v2: Failed header read:"
+               q_warn(KERN_WARNING "quota_v2: Failed header read:"
                       " expected=%zd got=%zd\n",
                        sizeof(struct v2_disk_dqheader), size);
                return 0;
@@ -106,7 +106,7 @@ static int v2_read_file_info(struct super_block *sb, int type)
        size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
               sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
        if (size != sizeof(struct v2_disk_dqinfo)) {
-               printk(KERN_WARNING "quota_v2: Can't read info structure on device %s.\n",
+               q_warn(KERN_WARNING "quota_v2: Can't read info structure on device %s.\n",
                        sb->s_id);
                return -1;
        }
@@ -167,7 +167,7 @@ static int v2_write_file_info(struct super_block *sb, int type)
        size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
               sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
        if (size != sizeof(struct v2_disk_dqinfo)) {
-               printk(KERN_WARNING "Can't write info structure on device %s.\n",
+               q_warn(KERN_WARNING "Can't write info structure on device %s.\n",
                        sb->s_id);
                return -1;
        }