Commit 47ae32d6a54955a041cdc30b06d0bb16e75f68d5
Committed by
Linus Torvalds
Linus Torvalds
1 parent
b227613841
Exists in
master
and in
4 other branches
[PATCH] relative atime
Add "relatime" (relative atime) support. Relative atime only updates the atime if the previous atime is older than the mtime or ctime. Like noatime, but useful for applications like mutt that need to know when a file has been read since it was last modified. A corresponding patch against mount(8) is available at http://userweb.kernel.org/~akpm/mount-relative-atime.txt Signed-off-by: Valerie Henson <val_henson@linux.intel.com> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Karel Zak <kzak@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Showing 4 changed files with 24 additions and 5 deletions Side-by-side Diff
fs/inode.c
| ... | ... | @@ -1177,13 +1177,27 @@ |
| 1177 | 1177 | return; |
| 1178 | 1178 | if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)) |
| 1179 | 1179 | return; |
| 1180 | + | |
| 1181 | + if (mnt->mnt_flags & MNT_RELATIME) { | |
| 1182 | + /* | |
| 1183 | + * With relative atime, only update atime if the | |
| 1184 | + * previous atime is earlier than either the ctime or | |
| 1185 | + * mtime. | |
| 1186 | + */ | |
| 1187 | + if (timespec_compare(&inode->i_mtime, | |
| 1188 | + &inode->i_atime) < 0 && | |
| 1189 | + timespec_compare(&inode->i_ctime, | |
| 1190 | + &inode->i_atime) < 0) | |
| 1191 | + return; | |
| 1192 | + } | |
| 1180 | 1193 | } |
| 1181 | 1194 | |
| 1182 | 1195 | now = current_fs_time(inode->i_sb); |
| 1183 | - if (!timespec_equal(&inode->i_atime, &now)) { | |
| 1184 | - inode->i_atime = now; | |
| 1185 | - mark_inode_dirty_sync(inode); | |
| 1186 | - } | |
| 1196 | + if (timespec_equal(&inode->i_atime, &now)) | |
| 1197 | + return; | |
| 1198 | + | |
| 1199 | + inode->i_atime = now; | |
| 1200 | + mark_inode_dirty_sync(inode); | |
| 1187 | 1201 | } |
| 1188 | 1202 | EXPORT_SYMBOL(touch_atime); |
| 1189 | 1203 |
fs/namespace.c
| ... | ... | @@ -368,6 +368,7 @@ |
| 368 | 368 | { MNT_NOEXEC, ",noexec" }, |
| 369 | 369 | { MNT_NOATIME, ",noatime" }, |
| 370 | 370 | { MNT_NODIRATIME, ",nodiratime" }, |
| 371 | + { MNT_RELATIME, ",relatime" }, | |
| 371 | 372 | { 0, NULL } |
| 372 | 373 | }; |
| 373 | 374 | struct proc_fs_info *fs_infop; |
| 374 | 375 | |
| ... | ... | @@ -1405,9 +1406,11 @@ |
| 1405 | 1406 | mnt_flags |= MNT_NOATIME; |
| 1406 | 1407 | if (flags & MS_NODIRATIME) |
| 1407 | 1408 | mnt_flags |= MNT_NODIRATIME; |
| 1409 | + if (flags & MS_RELATIME) | |
| 1410 | + mnt_flags |= MNT_RELATIME; | |
| 1408 | 1411 | |
| 1409 | 1412 | flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | |
| 1410 | - MS_NOATIME | MS_NODIRATIME); | |
| 1413 | + MS_NOATIME | MS_NODIRATIME | MS_RELATIME); | |
| 1411 | 1414 | |
| 1412 | 1415 | /* ... and get the mountpoint */ |
| 1413 | 1416 | retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd); |
include/linux/fs.h
| ... | ... | @@ -120,6 +120,7 @@ |
| 120 | 120 | #define MS_PRIVATE (1<<18) /* change to private */ |
| 121 | 121 | #define MS_SLAVE (1<<19) /* change to slave */ |
| 122 | 122 | #define MS_SHARED (1<<20) /* change to shared */ |
| 123 | +#define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */ | |
| 123 | 124 | #define MS_ACTIVE (1<<30) |
| 124 | 125 | #define MS_NOUSER (1<<31) |
| 125 | 126 |