diff --git a/include/linux/fs.h b/include/linux/fs.h index e8cd6b8396753901227a34659cedca367beb0926..b5a24ba83b6f17c7ae98bce197559a8d7e6ef60e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2227,6 +2227,13 @@ static inline void file_start_write(struct file *file) __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true); } +static inline bool file_start_write_trylock(struct file *file) +{ + if (!S_ISREG(file_inode(file)->i_mode)) + return true; + return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false); +} + static inline void file_end_write(struct file *file) { if (!S_ISREG(file_inode(file)->i_mode)) diff --git a/kernel/acct.c b/kernel/acct.c index 85389fe2abd0a95bf99d4abe6b1de63e09351c4c..8d6e145138bb9d2e39e93933177f63536d73d018 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -539,11 +539,16 @@ static void do_acct_process(struct bsd_acct_struct *acct, ac.ac_rw = encode_comp_t(ac.ac_io / 1024); ac.ac_swaps = encode_comp_t(0); + /* + * Get freeze protection. If the fs is frozen, just skip the write + * as we could deadlock the system otherwise. + */ + if (!file_start_write_trylock(file)) + goto out; /* * Kernel segment override to datasegment and write it * to the accounting file. */ - file_start_write(file); fs = get_fs(); set_fs(KERNEL_DS); /*