From: Amir Goldstein <amir73il@xxxxxxxxx> We would like to add file range information to pre-content events. Pass a struct file_range with offset and length to event handler along with pre-content permission event. The offset and length are aligned to page size, but we may need to align them to minimum folio size for filesystems with large block size. Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> Signed-off-by: Jan Kara <jack@xxxxxxx> Link: https://patch.msgid.link/88eddee301231d814aede27fb4d5b41ae37c9702.1731684329.git.josef@xxxxxxxxxxxxxx --- fs/notify/fanotify/fanotify.c | 11 +++++++-- fs/notify/fanotify/fanotify.h | 2 ++ fs/notify/fsnotify.c | 18 ++++++++++++++ include/linux/fsnotify.h | 4 ++-- include/linux/fsnotify_backend.h | 40 ++++++++++++++++++++++++++++++++ 5 files changed, 71 insertions(+), 4 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 224bccaab4cc..c1e4ae221093 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -549,9 +549,13 @@ static struct fanotify_event *fanotify_alloc_path_event(const struct path *path, return &pevent->fae; } -static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path, +static struct fanotify_event *fanotify_alloc_perm_event(const void *data, + int data_type, gfp_t gfp) { + const struct path *path = fsnotify_data_path(data, data_type); + const struct file_range *range = + fsnotify_data_file_range(data, data_type); struct fanotify_perm_event *pevent; pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp); @@ -565,6 +569,9 @@ static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path, pevent->hdr.len = 0; pevent->state = FAN_EVENT_INIT; pevent->path = *path; + /* NULL ppos means no range info */ + pevent->ppos = range ? &range->pos : NULL; + pevent->count = range ? range->count : 0; path_get(path); return &pevent->fae; @@ -802,7 +809,7 @@ static struct fanotify_event *fanotify_alloc_event( old_memcg = set_active_memcg(group->memcg); if (fanotify_is_perm_event(mask)) { - event = fanotify_alloc_perm_event(path, gfp); + event = fanotify_alloc_perm_event(data, data_type, gfp); } else if (fanotify_is_error_event(mask)) { event = fanotify_alloc_error_event(group, fsid, data, data_type, &hash); diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index e5ab33cae6a7..93598b7d5952 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -425,6 +425,8 @@ FANOTIFY_PE(struct fanotify_event *event) struct fanotify_perm_event { struct fanotify_event fae; struct path path; + const loff_t *ppos; /* optional file range info */ + size_t count; u32 response; /* userspace answer to the event */ unsigned short state; /* state of the event */ int fd; /* fd we passed to userspace for this event */ diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index d61f6bc679f1..e8625b61100a 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -203,6 +203,24 @@ static inline bool fsnotify_object_watched(struct inode *inode, __u32 mnt_mask, return mask & marks_mask & ALL_FSNOTIFY_EVENTS; } +/* Report pre-content event with optional range info */ +int fsnotify_pre_content(const struct path *path, const loff_t *ppos, + size_t count) +{ + struct file_range range; + + /* Report page aligned range only when pos is known */ + if (!ppos) + return fsnotify_path(path, FS_PRE_ACCESS); + + range.path = path; + range.pos = PAGE_ALIGN_DOWN(*ppos); + range.count = PAGE_ALIGN(*ppos + count) - range.pos; + + return fsnotify_parent(path->dentry, FS_PRE_ACCESS, &range, + FSNOTIFY_EVENT_FILE_RANGE); +} + /* * Notify this dentry's parent about a child's events with child name info * if parent is watching or if inode/sb/mount are interested in events with diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index d91aa064f0e4..87044acf8e79 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -154,7 +154,7 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, * read()/write() and other types of access generate pre-content events. */ if (unlikely(FMODE_FSNOTIFY_HSM(file->f_mode))) { - int ret = fsnotify_path(&file->f_path, FS_PRE_ACCESS); + int ret = fsnotify_pre_content(&file->f_path, ppos, count); if (ret) return ret; @@ -171,7 +171,7 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, } /* - * fsnotify_file_perm - permission hook before file access + * fsnotify_file_perm - permission hook before file access (unknown range) */ static inline int fsnotify_file_perm(struct file *file, int perm_mask) { diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 9bda354b5538..0d24a21a8e60 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -294,6 +294,7 @@ static inline void fsnotify_group_assert_locked(struct fsnotify_group *group) /* When calling fsnotify tell it if the data is a path or inode */ enum fsnotify_data_type { FSNOTIFY_EVENT_NONE, + FSNOTIFY_EVENT_FILE_RANGE, FSNOTIFY_EVENT_PATH, FSNOTIFY_EVENT_INODE, FSNOTIFY_EVENT_DENTRY, @@ -306,6 +307,17 @@ struct fs_error_report { struct super_block *sb; }; +struct file_range { + const struct path *path; + loff_t pos; + size_t count; +}; + +static inline const struct path *file_range_path(const struct file_range *range) +{ + return range->path; +} + static inline struct inode *fsnotify_data_inode(const void *data, int data_type) { switch (data_type) { @@ -315,6 +327,8 @@ static inline struct inode *fsnotify_data_inode(const void *data, int data_type) return d_inode(data); case FSNOTIFY_EVENT_PATH: return d_inode(((const struct path *)data)->dentry); + case FSNOTIFY_EVENT_FILE_RANGE: + return d_inode(file_range_path(data)->dentry); case FSNOTIFY_EVENT_ERROR: return ((struct fs_error_report *)data)->inode; default: @@ -330,6 +344,8 @@ static inline struct dentry *fsnotify_data_dentry(const void *data, int data_typ return (struct dentry *)data; case FSNOTIFY_EVENT_PATH: return ((const struct path *)data)->dentry; + case FSNOTIFY_EVENT_FILE_RANGE: + return file_range_path(data)->dentry; default: return NULL; } @@ -341,6 +357,8 @@ static inline const struct path *fsnotify_data_path(const void *data, switch (data_type) { case FSNOTIFY_EVENT_PATH: return data; + case FSNOTIFY_EVENT_FILE_RANGE: + return file_range_path(data); default: return NULL; } @@ -356,6 +374,8 @@ static inline struct super_block *fsnotify_data_sb(const void *data, return ((struct dentry *)data)->d_sb; case FSNOTIFY_EVENT_PATH: return ((const struct path *)data)->dentry->d_sb; + case FSNOTIFY_EVENT_FILE_RANGE: + return file_range_path(data)->dentry->d_sb; case FSNOTIFY_EVENT_ERROR: return ((struct fs_error_report *) data)->sb; default: @@ -375,6 +395,18 @@ static inline struct fs_error_report *fsnotify_data_error_report( } } +static inline const struct file_range *fsnotify_data_file_range( + const void *data, + int data_type) +{ + switch (data_type) { + case FSNOTIFY_EVENT_FILE_RANGE: + return (struct file_range *)data; + default: + return NULL; + } +} + /* * Index to merged marks iterator array that correlates to a type of watch. * The type of watched object can be deduced from the iterator type, but not @@ -863,9 +895,17 @@ static inline void fsnotify_init_event(struct fsnotify_event *event) { INIT_LIST_HEAD(&event->list); } +int fsnotify_pre_content(const struct path *path, const loff_t *ppos, + size_t count); #else +static inline int fsnotify_pre_content(const struct path *path, + const loff_t *ppos, size_t count) +{ + return 0; +} + static inline int fsnotify(__u32 mask, const void *data, int data_type, struct inode *dir, const struct qstr *name, struct inode *inode, u32 cookie) -- 2.35.3
