From ed44724b79d8e03a40665436019cf22baba80d30 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 19 Apr 2014 14:37:20 -0400 Subject: [PATCH] acct: switch to __kernel_write() Signed-off-by: Al Viro --- fs/internal.h | 1 - include/linux/fs.h | 1 + kernel/acct.c | 31 ++++++++++++------------------- 3 files changed, 13 insertions(+), 20 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index 4657424..9a2edba 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -131,7 +131,6 @@ extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan, /* * read_write.c */ -extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern int rw_verify_area(int, struct file *, const loff_t *, size_t); /* diff --git a/include/linux/fs.h b/include/linux/fs.h index e11d60c..4b7d57c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2335,6 +2335,7 @@ extern int do_pipe_flags(int *, int); extern int kernel_read(struct file *, loff_t, char *, unsigned long); extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t); +extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern struct file * open_exec(const char *); /* fs/dcache.c -- generic fs support functions */ diff --git a/kernel/acct.c b/kernel/acct.c index 807ebc5..8082d98 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -456,12 +456,16 @@ static void do_acct_process(struct bsd_acct_struct *acct, { struct pacct_struct *pacct = ¤t->signal->pacct; acct_t ac; - mm_segment_t fs; unsigned long flim; u64 elapsed, run_time; struct tty_struct *tty; const struct cred *orig_cred; + /* + * Accounting records are not subject to resource limits. + */ + flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; + current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; /* Perform file operations on behalf of whoever enabled accounting */ orig_cred = override_creds(file->f_cred); @@ -536,25 +540,14 @@ static void do_acct_process(struct bsd_acct_struct *acct, * 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. - */ - fs = get_fs(); - set_fs(KERNEL_DS); - /* - * Accounting records are not subject to resource limits. - */ - flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; - file->f_op->write(file, (char *)&ac, - sizeof(acct_t), &file->f_pos); - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; - set_fs(fs); - file_end_write(file); + if (file_start_write_trylock(file)) { + /* it's been opened O_APPEND, so position is irrelevant */ + loff_t pos = 0; + __kernel_write(file, (char *)&ac, sizeof(acct_t), &pos); + file_end_write(file); + } out: + current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; revert_creds(orig_cred); } -- 2.7.4