| Message ID | 20220516164718.2419891-8-shr@fb.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | io-uring/xfs: support async buffered writes | expand |
On Mon 16-05-22 09:47:09, Stefan Roesch wrote: > This splits off the functions need_file_update_time() and > do_file_update_time() from the function file_update_time(). > > This is required to support async buffered writes. > No intended functional changes in this patch. > > Signed-off-by: Stefan Roesch <shr@fb.com> ... > +int file_update_time(struct file *file) > +{ > + int err; > + struct inode *inode = file_inode(file); > + struct timespec64 now = current_time(inode); > + > + err = need_file_update_time(inode, file, &now); > + if (err < 0) > + return err; > + > + return do_file_update_time(inode, file, &now, err); > +} > EXPORT_SYMBOL(file_update_time); I guess 'ret' would be a more appropriate variable name than 'err'. Otherwise the patch looks good. Honza
On Mon, May 16, 2022 at 09:47:09AM -0700, Stefan Roesch wrote: > This splits off the functions need_file_update_time() and > do_file_update_time() from the function file_update_time(). > > This is required to support async buffered writes. > No intended functional changes in this patch. > > Signed-off-by: Stefan Roesch <shr@fb.com> > --- > fs/inode.c | 71 ++++++++++++++++++++++++++++++++++++------------------ > 1 file changed, 47 insertions(+), 24 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index a6d70a1983f8..1d0b02763e98 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -2054,35 +2054,22 @@ int file_remove_privs(struct file *file) > } > EXPORT_SYMBOL(file_remove_privs); > > -/** > - * file_update_time - update mtime and ctime time > - * @file: file accessed > - * > - * Update the mtime and ctime members of an inode and mark the inode > - * for writeback. Note that this function is meant exclusively for > - * usage in the file write path of filesystems, and filesystems may > - * choose to explicitly ignore update via this function with the > - * S_NOCMTIME inode flag, e.g. for network filesystem where these > - * timestamps are handled by the server. This can return an error for > - * file systems who need to allocate space in order to update an inode. > - */ > - > -int file_update_time(struct file *file) > +static int need_file_update_time(struct inode *inode, struct file *file, > + struct timespec64 *now) I think file_need_update_time() is easier to understand. > { > - struct inode *inode = file_inode(file); > - struct timespec64 now; > int sync_it = 0; > - int ret; > + > + if (unlikely(file->f_mode & FMODE_NOCMTIME)) > + return 0; Moving this into this generic helper and using the generic helper directly in file_update_atime() leads to a change in behavior for file_update_time() callers. Currently they'd get time settings updated even if FMODE_NOCMTIME is set but with this change they'd not get it updated anymore if FMODE_NOCMTIME is set. Am I reading this right? Is this a bugfix? And if so it should be split into a separate commit... > > /* First try to exhaust all avenues to not sync */ > if (IS_NOCMTIME(inode)) > return 0; > > - now = current_time(inode); > - if (!timespec64_equal(&inode->i_mtime, &now)) > + if (!timespec64_equal(&inode->i_mtime, now)) > sync_it = S_MTIME; > > - if (!timespec64_equal(&inode->i_ctime, &now)) > + if (!timespec64_equal(&inode->i_ctime, now)) > sync_it |= S_CTIME; > > if (IS_I_VERSION(inode) && inode_iversion_need_inc(inode)) > @@ -2091,15 +2078,49 @@ int file_update_time(struct file *file) > if (!sync_it) > return 0; > > + return sync_it; > +} > + > +static int do_file_update_time(struct inode *inode, struct file *file, > + struct timespec64 *now, int sync_mode) > +{ > + int ret; > + > /* Finally allowed to write? Takes lock. */ > if (__mnt_want_write_file(file)) > return 0; > > - ret = inode_update_time(inode, &now, sync_it); > + ret = inode_update_time(inode, now, sync_mode); > __mnt_drop_write_file(file); > > return ret; > } Maybe static int __file_update_time(struct inode *inode, struct file *file, struct timespec64 *now, int sync_mode) { int ret = 0; /* try to update time settings */ if (!__mnt_want_write_file(file)) { ret = inode_update_time(inode, now, sync_mode); __mnt_drop_write_file(file); } return ret; } reads a little easier and the old comment is a bit confusing imho. I'd just say we keep it short. > + > +/** > + * file_update_time - update mtime and ctime time > + * @file: file accessed > + * > + * Update the mtime and ctime members of an inode and mark the inode > + * for writeback. Note that this function is meant exclusively for > + * usage in the file write path of filesystems, and filesystems may > + * choose to explicitly ignore update via this function with the > + * S_NOCMTIME inode flag, e.g. for network filesystem where these > + * timestamps are handled by the server. This can return an error for > + * file systems who need to allocate space in order to update an inode. > + */ > + > +int file_update_time(struct file *file) My same lame complaint as before to make this kernel-doc. :) /** * file_update_time - update mtime and ctime time * @file: file accessed * * Update the mtime and ctime members of an inode and mark the inode or * writeback. Note that this function is meant exclusively for sage in * the file write path of filesystems, and filesystems may hoose to * explicitly ignore update via this function with the _NOCMTIME inode * flag, e.g. for network filesystem where these imestamps are handled * by the server. This can return an error for ile systems who need to * allocate space in order to update an inode. * * Return: 0 on success, negative errno on failure. */ int file_update_time(struct file *file) > +{ > + int err; > + struct inode *inode = file_inode(file); > + struct timespec64 now = current_time(inode); > + > + err = need_file_update_time(inode, file, &now); > + if (err < 0) > + return err; I may misread this but shouldn't this be err <= 0, i.e., if it returns 0 then we don't need to update time? > + > + return do_file_update_time(inode, file, &now, err); > +} > EXPORT_SYMBOL(file_update_time); > > /* Caller must hold the file's inode lock */ > @@ -2108,6 +2129,7 @@ int file_modified(struct file *file) > int ret; > struct dentry *dentry = file_dentry(file); > struct inode *inode = file_inode(file); > + struct timespec64 now = current_time(inode); > > /* > * Clear the security bits if the process is not being run by root. > @@ -2122,10 +2144,11 @@ int file_modified(struct file *file) > return ret; > } > > - if (unlikely(file->f_mode & FMODE_NOCMTIME)) > - return 0; > + ret = need_file_update_time(inode, file, &now); > + if (ret <= 0) > + return ret; > > - return file_update_time(file); > + return do_file_update_time(inode, file, &now, ret); > } > EXPORT_SYMBOL(file_modified); > > -- > 2.30.2 >
On 5/17/22 4:20 AM, Jan Kara wrote: > On Mon 16-05-22 09:47:09, Stefan Roesch wrote: >> This splits off the functions need_file_update_time() and >> do_file_update_time() from the function file_update_time(). >> >> This is required to support async buffered writes. >> No intended functional changes in this patch. >> >> Signed-off-by: Stefan Roesch <shr@fb.com> > > ... >> +int file_update_time(struct file *file) >> +{ >> + int err; >> + struct inode *inode = file_inode(file); >> + struct timespec64 now = current_time(inode); >> + >> + err = need_file_update_time(inode, file, &now); >> + if (err < 0) >> + return err; >> + >> + return do_file_update_time(inode, file, &now, err); >> +} >> EXPORT_SYMBOL(file_update_time); > > I guess 'ret' would be a more appropriate variable name than 'err'. > Otherwise the patch looks good. > I renamed it to ret in the next version of the patch series. > Honza
On 5/17/22 6:40 AM, Christian Brauner wrote: > On Mon, May 16, 2022 at 09:47:09AM -0700, Stefan Roesch wrote: >> This splits off the functions need_file_update_time() and >> do_file_update_time() from the function file_update_time(). >> >> This is required to support async buffered writes. >> No intended functional changes in this patch. >> >> Signed-off-by: Stefan Roesch <shr@fb.com> >> --- >> fs/inode.c | 71 ++++++++++++++++++++++++++++++++++++------------------ >> 1 file changed, 47 insertions(+), 24 deletions(-) >> >> diff --git a/fs/inode.c b/fs/inode.c >> index a6d70a1983f8..1d0b02763e98 100644 >> --- a/fs/inode.c >> +++ b/fs/inode.c >> @@ -2054,35 +2054,22 @@ int file_remove_privs(struct file *file) >> } >> EXPORT_SYMBOL(file_remove_privs); >> >> -/** >> - * file_update_time - update mtime and ctime time >> - * @file: file accessed >> - * >> - * Update the mtime and ctime members of an inode and mark the inode >> - * for writeback. Note that this function is meant exclusively for >> - * usage in the file write path of filesystems, and filesystems may >> - * choose to explicitly ignore update via this function with the >> - * S_NOCMTIME inode flag, e.g. for network filesystem where these >> - * timestamps are handled by the server. This can return an error for >> - * file systems who need to allocate space in order to update an inode. >> - */ >> - >> -int file_update_time(struct file *file) >> +static int need_file_update_time(struct inode *inode, struct file *file, >> + struct timespec64 *now) > > I think file_need_update_time() is easier to understand. > I renamed the function to file_needs_update_time(). >> { >> - struct inode *inode = file_inode(file); >> - struct timespec64 now; >> int sync_it = 0; >> - int ret; >> + >> + if (unlikely(file->f_mode & FMODE_NOCMTIME)) >> + return 0; > > Moving this into this generic helper and using the generic helper > directly in file_update_atime() leads to a change in behavior for > file_update_time() callers. Currently they'd get time settings updated > even if FMODE_NOCMTIME is set but with this change they'd not get it > updated anymore if FMODE_NOCMTIME is set. Am I reading this right? > Correct, this was not intended and will be addressed with the next version of the patch. > Is this a bugfix? And if so it should be split into a separate commit... > >> >> /* First try to exhaust all avenues to not sync */ >> if (IS_NOCMTIME(inode)) >> return 0; >> >> - now = current_time(inode); >> - if (!timespec64_equal(&inode->i_mtime, &now)) >> + if (!timespec64_equal(&inode->i_mtime, now)) >> sync_it = S_MTIME; >> >> - if (!timespec64_equal(&inode->i_ctime, &now)) >> + if (!timespec64_equal(&inode->i_ctime, now)) >> sync_it |= S_CTIME; >> >> if (IS_I_VERSION(inode) && inode_iversion_need_inc(inode)) >> @@ -2091,15 +2078,49 @@ int file_update_time(struct file *file) >> if (!sync_it) >> return 0; >> >> + return sync_it; >> +} >> + >> +static int do_file_update_time(struct inode *inode, struct file *file, >> + struct timespec64 *now, int sync_mode) >> +{ >> + int ret; >> + >> /* Finally allowed to write? Takes lock. */ >> if (__mnt_want_write_file(file)) >> return 0; >> >> - ret = inode_update_time(inode, &now, sync_it); >> + ret = inode_update_time(inode, now, sync_mode); >> __mnt_drop_write_file(file); >> >> return ret; >> } > > Maybe > > static int __file_update_time(struct inode *inode, struct file *file, > struct timespec64 *now, int sync_mode) > { > int ret = 0; > > /* try to update time settings */ > if (!__mnt_want_write_file(file)) { > ret = inode_update_time(inode, now, sync_mode); > __mnt_drop_write_file(file); > } > > return ret; > } > > reads a little easier and the old comment is a bit confusing imho. I'd > just say we keep it short. > I made the change. >> + >> +/** >> + * file_update_time - update mtime and ctime time >> + * @file: file accessed >> + * >> + * Update the mtime and ctime members of an inode and mark the inode >> + * for writeback. Note that this function is meant exclusively for >> + * usage in the file write path of filesystems, and filesystems may >> + * choose to explicitly ignore update via this function with the >> + * S_NOCMTIME inode flag, e.g. for network filesystem where these >> + * timestamps are handled by the server. This can return an error for >> + * file systems who need to allocate space in order to update an inode. >> + */ >> + >> +int file_update_time(struct file *file) > > My same lame complaint as before to make this kernel-doc. :) > > /** > * file_update_time - update mtime and ctime time > * @file: file accessed > * > * Update the mtime and ctime members of an inode and mark the inode or > * writeback. Note that this function is meant exclusively for sage in > * the file write path of filesystems, and filesystems may hoose to > * explicitly ignore update via this function with the _NOCMTIME inode > * flag, e.g. for network filesystem where these imestamps are handled > * by the server. This can return an error for ile systems who need to > * allocate space in order to update an inode. > * > * Return: 0 on success, negative errno on failure. > */ > int file_update_time(struct file *file) > I added the above kernel documentation, I only fixed a couple of typos. >> +{ >> + int err; >> + struct inode *inode = file_inode(file); >> + struct timespec64 now = current_time(inode); >> + >> + err = need_file_update_time(inode, file, &now); >> + if (err < 0) >> + return err; > > I may misread this but shouldn't this be err <= 0, i.e., if it returns 0 > then we don't need to update time? > Good catch. Fixed. >> + >> + return do_file_update_time(inode, file, &now, err); >> +} >> EXPORT_SYMBOL(file_update_time); >> >> /* Caller must hold the file's inode lock */ >> @@ -2108,6 +2129,7 @@ int file_modified(struct file *file) >> int ret; >> struct dentry *dentry = file_dentry(file); >> struct inode *inode = file_inode(file); >> + struct timespec64 now = current_time(inode); >> >> /* >> * Clear the security bits if the process is not being run by root. >> @@ -2122,10 +2144,11 @@ int file_modified(struct file *file) >> return ret; >> } >> >> - if (unlikely(file->f_mode & FMODE_NOCMTIME)) >> - return 0; >> + ret = need_file_update_time(inode, file, &now); >> + if (ret <= 0) >> + return ret; >> >> - return file_update_time(file); >> + return do_file_update_time(inode, file, &now, ret); >> } >> EXPORT_SYMBOL(file_modified); >> >> -- >> 2.30.2 >>
diff --git a/fs/inode.c b/fs/inode.c index a6d70a1983f8..1d0b02763e98 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2054,35 +2054,22 @@ int file_remove_privs(struct file *file) } EXPORT_SYMBOL(file_remove_privs); -/** - * file_update_time - update mtime and ctime time - * @file: file accessed - * - * Update the mtime and ctime members of an inode and mark the inode - * for writeback. Note that this function is meant exclusively for - * usage in the file write path of filesystems, and filesystems may - * choose to explicitly ignore update via this function with the - * S_NOCMTIME inode flag, e.g. for network filesystem where these - * timestamps are handled by the server. This can return an error for - * file systems who need to allocate space in order to update an inode. - */ - -int file_update_time(struct file *file) +static int need_file_update_time(struct inode *inode, struct file *file, + struct timespec64 *now) { - struct inode *inode = file_inode(file); - struct timespec64 now; int sync_it = 0; - int ret; + + if (unlikely(file->f_mode & FMODE_NOCMTIME)) + return 0; /* First try to exhaust all avenues to not sync */ if (IS_NOCMTIME(inode)) return 0; - now = current_time(inode); - if (!timespec64_equal(&inode->i_mtime, &now)) + if (!timespec64_equal(&inode->i_mtime, now)) sync_it = S_MTIME; - if (!timespec64_equal(&inode->i_ctime, &now)) + if (!timespec64_equal(&inode->i_ctime, now)) sync_it |= S_CTIME; if (IS_I_VERSION(inode) && inode_iversion_need_inc(inode)) @@ -2091,15 +2078,49 @@ int file_update_time(struct file *file) if (!sync_it) return 0; + return sync_it; +} + +static int do_file_update_time(struct inode *inode, struct file *file, + struct timespec64 *now, int sync_mode) +{ + int ret; + /* Finally allowed to write? Takes lock. */ if (__mnt_want_write_file(file)) return 0; - ret = inode_update_time(inode, &now, sync_it); + ret = inode_update_time(inode, now, sync_mode); __mnt_drop_write_file(file); return ret; } + +/** + * file_update_time - update mtime and ctime time + * @file: file accessed + * + * Update the mtime and ctime members of an inode and mark the inode + * for writeback. Note that this function is meant exclusively for + * usage in the file write path of filesystems, and filesystems may + * choose to explicitly ignore update via this function with the + * S_NOCMTIME inode flag, e.g. for network filesystem where these + * timestamps are handled by the server. This can return an error for + * file systems who need to allocate space in order to update an inode. + */ + +int file_update_time(struct file *file) +{ + int err; + struct inode *inode = file_inode(file); + struct timespec64 now = current_time(inode); + + err = need_file_update_time(inode, file, &now); + if (err < 0) + return err; + + return do_file_update_time(inode, file, &now, err); +} EXPORT_SYMBOL(file_update_time); /* Caller must hold the file's inode lock */ @@ -2108,6 +2129,7 @@ int file_modified(struct file *file) int ret; struct dentry *dentry = file_dentry(file); struct inode *inode = file_inode(file); + struct timespec64 now = current_time(inode); /* * Clear the security bits if the process is not being run by root. @@ -2122,10 +2144,11 @@ int file_modified(struct file *file) return ret; } - if (unlikely(file->f_mode & FMODE_NOCMTIME)) - return 0; + ret = need_file_update_time(inode, file, &now); + if (ret <= 0) + return ret; - return file_update_time(file); + return do_file_update_time(inode, file, &now, ret); } EXPORT_SYMBOL(file_modified);
This splits off the functions need_file_update_time() and do_file_update_time() from the function file_update_time(). This is required to support async buffered writes. No intended functional changes in this patch. Signed-off-by: Stefan Roesch <shr@fb.com> --- fs/inode.c | 71 ++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 47 insertions(+), 24 deletions(-)