Hello Namjae Jeon,
The patch 00532604c72e: "ext4: introduce new i_write_mutex to protect
fallocate" from May 26, 2014, leads to the following static checker
warning:
fs/ext4/file.c:195 ext4_file_write_iter()
warn: 'mutex:&EXT4_Iinode->i_write_mutex' is sometimes locked here and sometimes unlocked.
fs/ext4/file.c
104 mutex_lock(&EXT4_I(inode)->i_write_mutex);
105
106 /*
107 * Unaligned direct AIO must be serialized; see comment above
108 * In the case of O_APPEND, assume that we must always serialize
109 */
110 if (o_direct &&
111 ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
112 !is_sync_kiocb(iocb) &&
113 (file->f_flags & O_APPEND ||
114 ext4_unaligned_aio(inode, from, pos))) {
115 unaligned_direct_aio = true;
116 ext4_unwritten_wait(inode);
117 }
118
119 mutex_lock(&inode->i_mutex);
120 if (file->f_flags & O_APPEND)
121 iocb->ki_pos = pos = i_size_read(inode);
122
123 /*
124 * If we have encountered a bitmap-format file, the size limit
125 * is smaller than s_maxbytes, which is for extent-mapped files.
126 */
127 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
128 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
129
130 if ((pos > sbi->s_bitmap_maxbytes) ||
131 (pos == sbi->s_bitmap_maxbytes && length > 0)) {
132 mutex_unlock(&inode->i_mutex);
133 ret = -EFBIG;
We want to always unlock on this path but it only unlocks when
"unaligned_direct_aio" is true.
134 goto errout;
135 }
136
[ snip ]
192 errout:
193 if (unaligned_direct_aio)
194 mutex_unlock(&EXT4_I(inode)->i_write_mutex);
195 return ret;
196 }
regards,
dan carpenter
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
