From: Deepa Dinamani <deepa.kernel@gmail.com> To: viro@zeniv.linux.org.uk, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Cc: torvalds@linux-foundation.org, tglx@linutronix.de, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, arnd@arndb.de, y2038@lists.linaro.org Subject: [PATCH v5 4/5] vfs: Add timestamp_truncate() api Date: Sat, 8 Apr 2017 12:37:46 -0700 [thread overview] Message-ID: <1491680267-11171-5-git-send-email-deepa.kernel@gmail.com> (raw) In-Reply-To: <1491680267-11171-1-git-send-email-deepa.kernel@gmail.com> timespec_trunc() function is used to truncate a filesystem timestamp to the right granularity. But, the function does not clamp tv_sec part of the timestamps according to the filesystem timestamp limits. Also, timespec_trunc() is exclusively used for filesystem timestamps. Move the api to be part of vfs. The replacement api: timestamp_truncate() also alters the signature of the function to accommodate filesystem timestamp clamping according to flesystem limits. Note that the clamp_t macro is used for clamping here as vfs is not yet using struct timespec64 internally. This is required for compilation purposes. Also note that clamp won't do the right thing for timestamps beyond 2038 on 32-bit machines until the vfs uses timespec64. After the vfs is transitioned to use timespec64 for timestamps, clamp_t() can be replaced by clamp(). Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> --- fs/inode.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index a0c1522..8ad5561 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2103,6 +2103,36 @@ void inode_nohighmem(struct inode *inode) EXPORT_SYMBOL(inode_nohighmem); /** + * timestamp_truncate - Truncate timespec to a granularity + * @t: Timespec + * @inode: inode being updated + * + * Truncate a timespec to the granularity supported by the fs + * containing the inode. Always rounds down. gran must + * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). + */ +struct timespec timestamp_truncate(struct timespec t, struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + unsigned int gran = sb->s_time_gran; + + t.tv_sec = clamp_t(time64_t, t.tv_sec, sb->s_time_min, sb->s_time_max); + + /* Avoid division in the common cases 1 ns and 1 s. */ + if (gran == 1) { + /* nothing */ + } else if (gran == NSEC_PER_SEC) { + t.tv_nsec = 0; + } else if (gran > 1 && gran < NSEC_PER_SEC) { + t.tv_nsec -= t.tv_nsec % gran; + } else { + WARN(1, "illegal file time granularity: %u", gran); + } + return t; +} +EXPORT_SYMBOL(timestamp_truncate); + +/** * current_time - Return FS time * @inode: inode. * @@ -2121,6 +2151,6 @@ struct timespec current_time(struct inode *inode) return now; } - return timespec_trunc(now, inode->i_sb->s_time_gran); + return timestamp_truncate(now, inode); } EXPORT_SYMBOL(current_time); -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Deepa Dinamani <deepa.kernel@gmail.com> To: viro@zeniv.linux.org.uk, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Cc: arnd@arndb.de, y2038@lists.linaro.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org Subject: [PATCH v5 4/5] vfs: Add timestamp_truncate() api Date: Sat, 8 Apr 2017 12:37:46 -0700 [thread overview] Message-ID: <1491680267-11171-5-git-send-email-deepa.kernel@gmail.com> (raw) In-Reply-To: <1491680267-11171-1-git-send-email-deepa.kernel@gmail.com> timespec_trunc() function is used to truncate a filesystem timestamp to the right granularity. But, the function does not clamp tv_sec part of the timestamps according to the filesystem timestamp limits. Also, timespec_trunc() is exclusively used for filesystem timestamps. Move the api to be part of vfs. The replacement api: timestamp_truncate() also alters the signature of the function to accommodate filesystem timestamp clamping according to flesystem limits. Note that the clamp_t macro is used for clamping here as vfs is not yet using struct timespec64 internally. This is required for compilation purposes. Also note that clamp won't do the right thing for timestamps beyond 2038 on 32-bit machines until the vfs uses timespec64. After the vfs is transitioned to use timespec64 for timestamps, clamp_t() can be replaced by clamp(). Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> --- fs/inode.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index a0c1522..8ad5561 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2103,6 +2103,36 @@ void inode_nohighmem(struct inode *inode) EXPORT_SYMBOL(inode_nohighmem); /** + * timestamp_truncate - Truncate timespec to a granularity + * @t: Timespec + * @inode: inode being updated + * + * Truncate a timespec to the granularity supported by the fs + * containing the inode. Always rounds down. gran must + * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). + */ +struct timespec timestamp_truncate(struct timespec t, struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + unsigned int gran = sb->s_time_gran; + + t.tv_sec = clamp_t(time64_t, t.tv_sec, sb->s_time_min, sb->s_time_max); + + /* Avoid division in the common cases 1 ns and 1 s. */ + if (gran == 1) { + /* nothing */ + } else if (gran == NSEC_PER_SEC) { + t.tv_nsec = 0; + } else if (gran > 1 && gran < NSEC_PER_SEC) { + t.tv_nsec -= t.tv_nsec % gran; + } else { + WARN(1, "illegal file time granularity: %u", gran); + } + return t; +} +EXPORT_SYMBOL(timestamp_truncate); + +/** * current_time - Return FS time * @inode: inode. * @@ -2121,6 +2151,6 @@ struct timespec current_time(struct inode *inode) return now; } - return timespec_trunc(now, inode->i_sb->s_time_gran); + return timestamp_truncate(now, inode); } EXPORT_SYMBOL(current_time); -- 2.7.4 _______________________________________________ Y2038 mailing list Y2038@lists.linaro.org https://lists.linaro.org/mailman/listinfo/y2038
next prev parent reply other threads:[~2017-04-08 19:39 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-04-08 19:37 [PATCH v5 0/5] vfs: Add timestamp range check support Deepa Dinamani 2017-04-08 19:37 ` Deepa Dinamani 2017-04-08 19:37 ` [PATCH v5 1/5] vfs: Add file timestamp range support Deepa Dinamani 2017-04-08 19:37 ` Deepa Dinamani 2017-04-08 19:37 ` [PATCH v5 2/5] vfs: Add checks for filesystem timestamp limits Deepa Dinamani 2017-04-08 20:04 ` Linus Torvalds 2017-04-08 20:04 ` Linus Torvalds 2017-04-09 2:58 ` Deepa Dinamani 2017-04-25 19:47 ` Arnd Bergmann 2017-04-25 20:02 ` Linus Torvalds 2017-04-25 20:31 ` [Y2038] " Arnd Bergmann 2017-04-25 20:31 ` Arnd Bergmann 2017-04-25 20:35 ` [Y2038] " Linus Torvalds 2017-04-25 20:35 ` Linus Torvalds 2017-04-25 21:23 ` [Y2038] " Arnd Bergmann 2017-04-25 21:23 ` Arnd Bergmann 2017-04-08 19:37 ` [PATCH v5 3/5] ext4: Initialize timestamps limits Deepa Dinamani 2017-04-08 19:37 ` Deepa Dinamani 2017-04-08 19:37 ` Deepa Dinamani [this message] 2017-04-08 19:37 ` [PATCH v5 4/5] vfs: Add timestamp_truncate() api Deepa Dinamani 2017-04-08 19:37 ` [PATCH v5 5/5] utimes: Clamp the timestamps before update Deepa Dinamani 2017-04-08 19:37 ` Deepa Dinamani
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